Philippine Electrical Wiring – Building our Philippine House

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Wiring your Philippine house.  Philippine electrical wiring.   As part of our project to build our house in the Philippines, we had to learn about Philippine residential electrical systems. Here’s what we’ve learned. As with our other writings, we do our best to chronicle our missteps as well as our successes, so that our readers get slice of reality about coming to the Philippines and building a house, not a fairy tale.  This is not a how-to guide, it’s a description of our experiences.

The transformer serving our house

The transformer serving our house

Our pole-mounted meter

Our pole-mounted meter.  The wires on the left provide power to the meter, the black load wire on the right goes back up the pole and connects to the duplex utility feed or “drop” which connects to the house wiring at the weather head.

From the standpoint of electrical engineering theory, the Philippine system is similar to that used in the U.S. and Europe.  From the utility pole to the residence panel box we have one or two load wires and neutral conductor. We have a ground (earth) provided by the homeowner.   You can explore the technical details at http://en.wikipedia.org/wiki/Earthing_system and various other sites.   However there are some big differences in materials and techniques between the USA, Europe, the U.K. and the Philippines. Looking at how things were done when we built our Philippine house may help other considering house building in the Philippines to get an idea how things are done here.  One final note.  The Philippine electricians we have met have been quite professional.  It’s best to hire an electrical engineer to do your plan (you will need it for your building permit), and have good electricians to do the work.  Wage rates are negotiable and far more reasonable than in your home country.  We hope this essay will be of help in making you a more knowledgeable home builder.

First, some background.  Understanding “hot” neutral and ground.  This from Schneider Electric helps explain the purpose and nature of each of the three conductors.

“Electrical power flows in the form of current, which must pass through the equipment and then return to the power source. Therefore, it is convenient to think of one wire to the load being the “source” wire and one being the “return” wire. This simple model is appropriate for DC systems but does not work for an AC system because the flow of the power is continually reversing direction with a frequency of 50 or 60 times per second. From the point of view of the equipment or the power source, the source and return wires are constantly being interchanged. In fact, no equipment can tell which wire is which! It is easily demonstrated that the two power wires to any piece of AC equipment can be interchanged without any effect on function. In fact, in Europe [and the Philippines], the plug on a piece of equipment can be plugged in either way! This fact of symmetry seems to be at odds with the distinct labeling of the AC power wires as “hot” and “neutral”. The reason that one of the power wires is named “neutral” is because it is connected directly to the building ground connection at the circuit breaker panel. Therefore it is connected directly to the grounding (third) wire. In essence, then, two of the three wires at the wall receptacle are actually grounded wires, one being used for power flow, and the other connected only to exposed metal parts on the equipment. The power wire that is grounded is called the “neutral” wire because it is not dangerous with respect to exposed metal parts or plumbing. The “hot” wire gets its name because it is dangerous. The grounding of the neutral wire is not related to the operation of electrical equipment but is required for reasons of safety.” [minor edits] http://www.apcmedia.com/salestools/SADE-5TNQYQ_R0_EN.pdf

TYPES OF ELECTRICAL SERVICE IN THE PHILIPPINES. There are two main types of residential electrical service in the Philippines.

MANILA AND CITIES: Three wire 120/240V Systems.  In Manila, Iloilo City and other large Philippine cities, residences are supplied with 240 volt, alternating current, 60 cycle power.  Power from the utility transformer to the residence arrives through three wires, two 120 VAC load (“hot”) wires and a single neutral.  Circuits in the residence are generally wired to supply 240 VAC to outlets using the two 120 VAC load wires, much the same as a heavy appliance (dryer, hot water heater etc.) would be supplied in the U.S. All small and large appliances sold in the Philippines are designed to use 240 VAC, 60C.

However, it is possible to wire in 120 VAC circuits and outlets by using only one of the load wires and a neutral.  These 120 V outlets are seen in hotels, some condos and other places which expect American visitors.   Visitors must keep in mind that the Philippines uses the same style of wall outlets as you see in America, but that the outlet is supplying 240 V, not 120 V.  Plugging a 120 V appliance into a 240 V outlet will generally destroy the appliance.

It seems likely that the American-style 120 / 240  VAC 60 cycle used in Manila may have been the result of the fact that electrical systems in Philippine cities were expanded during the American occupation of the Philippines between 1899 and WWII.  There may be areas around the big former U.S. military bases (Clark and Subic) which are wired for 120 VAC service.

OUTSIDE OF BIG CITIES: Two wire 230V Systems  Areas outside of the old established cities were electrified later and use a different and more economical system using a two wire service drop to the residence.  This consists of one 230 VAC load wire and one neutral wire.  120 VAC cannot be supplied by this type of system unless the property owner, at his own expense and with the cooperation of the utility company, installs his own transformer at the utility pole, a transformer having a secondary winding which can supply 120 VAC.  This is not impossible as many utility transformers are recycled from the U.S., but it is expensive and in our view the 230 V systems are better unless the homeowner ships expensive appliances from the U.S.  It will be difficult to find parts and service for these imported 120 V appliances.

Much of the rest of the world runs on 220-240 VAC but 50 cycle rather than 60 cycle found in the Philippines, creating a problem in importing some European appliances for use in the Philippines.

A FIELD GUIDE TO ELECTRICAL SYSTEM IDENTIFICATION.

How can you identify the type of power system you have?  You may look up at the utility feed wires leading from the meter or pole to your house — or a neighbor’s house.  If there are three  wires you probably have two 115 volt load (“hot”) wires and a neutral.  If you have two wires you probably have a single 230 volt load wire and a single combined neutral/ground wire.  With a few exceptions,  Philippine utilities deliver 230 volt, 60 cycle power to your house, but there are differences based on where you live.  Our comments below mostly apply to areas in the Philippines which supply residences using a single 230 volt load wire and a neutral wire to your residence.  They are not fully applicable to urban areas using two 110 volt load wires (including Manila) or to systems around former American military bases.

For our purposes let’s call the three wire urban systems as “three wire 120/240V systems” and the two wire systems as “two wire 230V systems”.

Our residence is located in a rural location served by an electrical cooperative so we have a 230V two wire electrical supply.

Duplex cable from meter to weather head

Duplex cable from meter to weather head

Here is a photo of the point where the utility company service drop or cable  joins with our house wiring at the weather head and enters the house.

The utility feed cables on the right are from the pole, one black load wire and one un-insulated neutral wire.  The black and green feed wires on the left go into our attic and through conduit to our panel box. Again, from the fact that there is only one load wire, we can guess that we have a two wire 230 v. system.  If you had seen two black wires and a neutral leading from the pole to the house, you’re probably dealing with a three wire 120/240V system.

The meter-to-house wire is referred to as “duplex cable”.  If it was three wire it would be referred to as “triplex”.  Our duplex feed cable is a #6 AWG load wire which is insulated and wound with an un-insulated neutral wire.  Both are aluminum.  We had to pay for the duplex wire extending from the meter to our house. We paid about P17 per meter for this cable at Western Lamp, an electrical supply house in Iloilo City. The utility may provide the wire and/or the meter and bill you for it monthly until it’s paid for.  You’ll pay more this way.

Also note that the utility feed is aluminum whereas the panel feed wire is copper.  The two have to be spliced together at the weather head.  Ideally this is done with a special compression splice and splicing tool because copper and aluminum have a different coefficient of expansion, plus the two materials are subject to electrochemical reaction.

Splice crimping tool

Splice crimping tool

While the default service drop is the 6AWG aluminum cable, we recently replaced ours with 4AWG aluminum cable to better accommodate a new 2HP air conditioner. Remember that all resistance losses from the meter are paid by the homeowner. We paid about P30 per meter for each strand of the 4AWG cable. We were happy to tear out and replace the old 6AWG wire which had several splices with heavier cable all connected with proper crimp connectors. The total cost for replacing the 60 meters of service drop was P3,000. If there are any electrical engineers out there, they could calculate the difference in resistance losses between the larger and smaller service drops.

Replacing thin 6AWG drop cable with 4AWG

Replacing thin 6AWG drop cable with 4AWG

At the bottom of each electrical pole is (or should be) a ground rod which is connected to the transformer and to the line serving your house. These provide a ground to the system, but it’s critical to have your own separate ground to ensure that your own neutral wiring is properly grounded.  The utility’s ground is to make their system work.  The home owner’s ground is to protect the household and its wiring system from electrical hazards.

Ground rod at pole

Ground rod at pole

Many Americans considering a move to the Philippines want to know if they can get 120 volt power in the Philippines and whether or not they should bring their 120 volt appliances with them.  If your residence has the two-wire 230 volt system, 120 volts is not going to be available except by means of a step-down transformer inside the house.  Step down transformers generate heat and waste power, but are quite popular in the Philippines and available in almost all hardware stores.

There is no right answer to the question about bringing appliances from the U.S. to the Philippines.  Items used only infrequently, say a food processor or sewing machine, it might make sense to bring. We would not bring Items in constant use, such as a refrigerator.   We have seen Filipinos using 120v power tools, dragging around a step-down transformer.  Bob sold his power tools before leaving the U.S. and bought new ones in the Philippines.  Just remember that electrical plugs in the U.S. and the Philippines look the same, but the first time you plug your 120v gadget into a 230v circuit, will likely be the end of that item.

Foreigners from places other than the U.S. may have an easier time but, even if their appliances are made for 230v use, have to investigate the compatibility of 50 cycle appliances when used on 60 cycle Philippine circuits.

Step-down transformer

Step-down transformer.  It plugs into a 230 volt receptacle and provides 120 volt power

Some expats have bought and installed their own power pole transformers and have been able to get 120v that way. This is an expensive option, possibly more expensive than buying new 230v appliances.

We have seen above that the utility drop cable attaches to the house wiring at the weather head.  Now to follow the wiring from this point to the panel or circuit breaker box.

Our electrical engineer originally proposed a 125 amp panel box for our house.  He probably did this because he was designing for a foreigner who would have hot water and air conditioning throughout and every conceivable electrical appliance and gadget.  We went to the engineer and informed him of our plans and he agreed to a 100 amp panel box using #2 AWG wire.  Even with a 100 amp panel box, at 230 volts we have an almost 25KW capacity, far in excess of any load we can possibly use.

In the Philippines, metric sizing is replacing the AWG (American Wire Gauge) system.  Our #2 AWG cable is designated as 30mm sq., under the metric system. This cable is expensive.   Undersized cable is often used.  Our electricians were astounded that we were using such heavy cable in a residence.  To run the main feed into the attic we used 1″ galvanized pipe.  It should have been 32mm or 1¼”.  There are charts available which specify the required size of conduit. Cable overcrowded in conduit can overheat.

Running the entrance cable in the attic

Running the entrance cable in the attic

The main feed cable has come into the attic through the weather head.  In this photo, the workers are feeding the wire through plastic conduit.  The main feed cable does not go directly to the panel box.  It first goes to a switch allowing the panel box to be supplied by the electrical utility or, in the event of a power failure, by a backup generator.  This switch ensures that no power from the generator can flow into the utility lines, placing utility workers at risk.  It also allows us to put the switch in a neutral position where no power from either source is flowing to the panel box.  This allows us to safely work on the panel box without having the utility company remove the meter.

knife_switch

This photo shows the double-pole, double throw switch which switches between utility company power and power from our generator.  The capacity of the switch is 100 amps.  It cost about $80.  Our generator hookup is the simplest and cheapest kind.  Power from our utility comes in at the top of the switch.  Power from the generator (when running) comes in at the bottom.  The middle terminals connect to the panel box.   Normally, utility power flows through the DPDT switch to the panel box.  During a blackout, the switch is changed to the lower position and the generator is started.  With this simple set-up, power from the generator flows to all circuits.  Because the capacity of the generator is limited, less than what’s available from the utility company, we check to see that high consumption circuits (mostly air conditioning) are not on when we start the generator.  After the generator is running, we have used one of our air conditioners powered by the generator without a problem.

There are more complex switching systems which automatically determine which circuits will be active when the generator is being used.  There are also systems in which the generator automatically starts and automatically switches over when a blackout occurs.  An automatic system would improve security at times when power goes out at night and one has the choice of going outside in the middle of the night to start the generator or to stay inside a dark house, hoping the security lights, air conditioners and fans will come back on soon.

Subpanel for generator

Subpanel for generator

Above is a snapshot of a generator switch which uses a separate circuit and breaker for circuits which are energized when the generator is running.  Also the knife switch is in a box, a good idea!

We did install battery operated emergency lights to illuminate our front porch and garage during power outages.

PANEL BOXES.  The knife switch normally delivers utility power to the main buses of the panel box via #2 AWG (30mm²) cable.  This brings us to a discussion about panel boxes.  Panel (circuit breaker boxes) boxes vary in quality, the number of circuits they can handle, the type of breakers they use and so forth.  We are far from being panel box experts, but we will share our experiences.

If you buy your panel box and breakers in a hardware store you’ll generally find cheaper brands such as Koten, Meiji, Royu and so forth.  We also saw crude copies of GE breakers labeled as “American”.  Some of the panel boxes at hardware stores even had aluminum buses.  It should be noted that these brands are not necessarily cheaper than GE brand breakers sold at specialized electrical supply stores.

If you go to an electrical supply outfit which caters to electricians, you find a wider range of products with better quality and lower prices.  The counter staff at these places can be quite knowledgeable.  Two good places in Iloilo City are Western Lamp and Eastman Electric.  Always ask for a discount, especially if you are buying in quantity.

Bolt on breaker

Bolt on breaker

Plug in breaker showing panel box copper bus bars

Plug in breaker showing panel box copper bus bars

We bought a good quality twenty-circuit panel box with a sturdy copper buses for about P4,100 at Western Lamp in Iloilo City. This box uses GE-style plug-in breakers.  We were offered a choice between a panel box using plug-in or bolt-on breakers.  We chose plug-in because that’s what we were familiar with in the U.S.  As we will see, that was a mistake.

This type of panel box is really engineered for use with the 120-240v three wire type of system but can be used with the 230v three wire systems too.  In a 120-240v three wire system, the two main buses each carry 120v. The buses on the plug-in panel boxes have a zig-zag type of arrangement which works well if your two buses are hot and you have separate neutral and ground busses – such as in the U.S. or in Manila or other Philippine cities.  When you plug in a single-pole breaker you connect to one bus and end up with a 120v circuit.  If you use a double-pole breaker you connect to both buses and get a 240v circuit.

However, if you have a 230v two wire supply, you will use one of the buses as a load bus and the other as a neutral bus.  This works fine except that you have to carefully check the polarity of your circuits to be sure the neutral wires always connect with the neutral bus.  The zig-zag or staggered  buses mean that the order of the load and neutral buses are reversed on the left and right buses.

Diagram of panel box with staggered bus

Diagram of panel box with staggered bus

The maximum capacity of the plug in breakers is 100 amps, so if you need a panel box with a larger capacity, buy one designed for bolt-on breakers.  Further, in Iloilo City single-pole breakers are not available in the plug-in style.  We strongly recommend a panel box with bolt on breakers.

Here is when we got into trouble.  We decided to use single-pole breakers.  We only had one load wire.  What was the point in “protecting” the neutral side of the circuit, we asked ourselves?  It’s a general rule that neutral lines should not be switched or fused.  So, we bonded the two panel box busses together and made them both hot with 230v.  We would use single pole breakers protecting the load wires and tie the neutrals to a separate neutral bus.  This simultaneously converted our twenty breaker double pole box to a forty circuit single-pole box.  Brilliant!

bus with captions

Not really.  Since we found that single pole breakers were not available for our plug-in panel box, we looked at double pole breakers and they seemed to be two single pole breakers tied together.  We cut the links on the handles and wired up our panel box.  Everything seemed to work just fine.

Panel box wired single pole

Panel box wired single pole.  Note that only the right bus was used.

Gradually, we learned that circuit breakers are much more complicated than we thought.  Breakers provide protection for both instantaneous large surges in current (short circuit) and lower, longer term overages from an overloaded circuit.

Inside a circuit breaker (Wikipedia)

Inside a circuit breaker (Wikipedia) This is a European DIN mount breaker.

  1. Actuator lever – used to manually trip and reset the circuit breaker. Also indicates the status of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip even if the lever is held or locked in the “on” position. This is sometimes referred to as “free trip” or “positive trip” operation.
  2. Actuator mechanism – forces the contacts together or apart.
  3. Contacts – Allow current when touching and break the current when moved apart.
  4. Terminals
  5. Bimetallic strip.
  6. Calibration screw – allows the manufacturer to precisely adjust the trip current of the device after assembly.
  7. Solenoid
  8. Arc divider/extinguisher

The assumption that the two halves of DP breakers can serve as SP breakers proved to be very wrong.  The double-pole breakers are NOT just two single pole breakers physically joined.  We found this out the hard way when we had a total short in one of our circuits and the 20 amp breaker did not trip, but instead melted a #12 AWG wire.  This must have been a huge overload, far beyond 20 amps.

We then tested the breakers on a test circuit.  We found that only one side of our double pole breaker provide short circuit protection. It’s unknown which side may provide over current protection.  Presumably, breakers made to be used as single-pole provide both protections in a single breaker, as do double-pole breakers used as a unit.

We decided we were not so smart after all. Since we had a plug-in type of panel box for which single-pole breakers are not available, we had no choice but to wire our plug-in style panel box, as many local electricians do, using double-pole breakers.

We took out the link we had installed connecting the two panel box bus bars and bought new double-pole breakers.   Now, one of the buses was hot, the other bus was neutral. When a double pole breaker is installed, one pole of the breaker protects the load wire and one the neutral wire for each branch circuit.

We used a specific GE double pole breaker which is sold and in almost universal use here – the TQL2415X or TQL2420X. Our electrical supply store only sells GE brand breakers. I could not find these “X-suffix” breakers in the huge online GE breaker directory, but did read elsewhere that the X designation is for “special purpose” applications.  The GE breakers sold here are 240/415 volt rated.

GE_breaker_label

Almost all U.S. residential single pole breakers are made for circuits with 120v loads.  The breakers for the U.S. are generally rated at 120-240v.  The GE breakers sold in the Philippines are 240/415 volt rated (see photo above). There may also be internal design differences between the breakers used in the U.S. and in the Philippines which might affect the safety and effectiveness of your system. Breaker engineering is way beyond our comprehension.  We feel it’s best to buy product designed for the local market and electrical systems.

Therefore, we do not recommend bringing breakers from the U.S. The part numbers of the locally sold GE breakers are not the same and we are not certain if they are designed to work properly with 230v two wire systems.  Perhaps, after being burned (literally!) experimenting with breakers, we were not in a mood for further experiments.

We have not seen Siemens or Square D or C-H breakers.  Perhaps they are available in Manila?  The GE double pole breakers we used cost P400  each – after negotiation.  Single-pole GE breakers are available for bolt-in panel boxes.  These should work fine on a panel box made for them but, as we have said, we have decided to follow local wiring customs after our earlier misadventure and given the fact that we had already installed a plug-in type panel box.

Panel Box

Panel Box wired using double pole breakers, one pole load, one pole neutral.

OUR RECOMMENDATION: We live in an area where electricians are called on to install both 230 volt two-wire systems and 240 volt three-wire systems.  On the three wire systems, the electricians must install a panel box using double-pole breakers.  On the two wire systems they can use either single or double-pole breakers.  We feel we were right in the first place in thinking that single pole breakers are a good (and more economical)  choice to the 230 volt two wire systems. What is the point on spending more to install double pole breakers?  Unfortunately, we bought and installed a plug-in style panel box and ended up with no choice but to use double pole breakers.  Starting from scratch, we feel the best option for the 230V two-wire systems is a good bolt-on panel box using genuine GE single-pole bolt-on breakers.

GROUNDING.  One last, but important part of panel box installation is proper grounding.  While the neutral line may be (or may not be) grounded at the base of the utility pole, it is essential that the residence have its own grounding system.  This can be in the form of grounding pipes or rods.  The Philippine 230v two wire system is called a multi-ground system because it depends on a distribution ground provided by the utility company and a protective ground at each panel box.

Rather than using a grounding rod pounded into the soil, we attached brass “acorn” clamps to the rebar in one of the house’s main columns. This rebar leads underground to a mass of rebar in the base of the footer and ultimately to all of the rebar and concrete of the house.  A #6 AWG copper conductor runs from the clamp to the panel box.  Rebar grounding is permitted by both the PEC and NEC.   One advantage of the rebar ground being in the attic is that it is protected from the corrosion or damage risk outdoor ground rods are prone to.

Grounding clamp on rebar in attic

Grounding clamp on rebar in attic

See comments below why some feel rebar does not make a good protective ground. See this link for an excellent discussion of grounding.  http://www.creia.org/files/public/grounding_electrode_locked.pdf

Most Philippine houses are not wired with three-prong, grounded outlets.  Most outlets have only a load wire and a neutral wire. The quality of grounding of the neutral wire can be uncertain due to improper earthing at the pole or in the residence.  If you’ve spent any time in the Philippines, you’ve probably been repeatedly shocked by your computer, refrigerator and so forth.   The metal parts of these appliances either have no ground (earth) connection and/or the neutral is not properly grounded. When you touch them with bare feet on a tile, you become the ground.  Since bare feet on tile are a pleasure of Philippine retirement, this is best avoided.

Sometimes proper polarity is not maintained in the wiring.  Make sure the neutral (white) wires in branch circuits are attached to the neutral bus in the panel box.  Otherwise the metal parts of an appliance may be connected to a hot wire rather than a neutral.

Unfortunately, it is typical for appliances sold in the Philippines to lack a grounding prong on the plug.  The rusty plug shown above not only does not have a grounding lug, the blades are identical, so that it can be plugged in without regard to the polarity of the outlet.  Generally, outlets have one wider slot and one narrow slot so that plugs can only be plugged in in one way.  This is to ensure that the polarity of the appliance connection is correct, that the neutral rather than hot wire is attached to the metal case of the appliance. See “Polarity Matters in AC Wiring”  http://www.phillylicensedelectrician.com/polarity-matters-in-ac-wiring/

Fortunately, grounded outlets are readily available and that’s what we used.  We ran a separate #14 AWG ground wire to each outlet.  This wire connects to the ground bus in the panel box and from there to our earthing system.  The neutral and ground are bonded in the panel box and only in the panel box.  This neutral to ground bonding is a must.  See Mike Holt’s discussion at http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Neutral-to-GroundConnections~20020521.htm

grounding-lead

Appliance cord with unpolarized plug and ground lead

 We hardly ever see grounded three prong plugs on appliances sold in the Philippines.  That’s because few houses have grounded outlets.  Sometimes you’ll get a two prong plug with a separate ground wire that the homeowner is left to connect — or not. We suspect that a very small percentage of these are ever connected.  For that reason, the ground wire is more of a fig leaf than a real solution.  Generally we have found that if the neutral wire is well grounded (earthed), these shocks are less common.  Still, it’s best to use these ground wires to prevent serious shocks in case of a failure which connects the hot wire to the metal parts of the appliance.  These grounding leads should always go to a ground (earth) not a neutral.  The best approach may be to cut the original 2-prong plug off of the appliance cord and install a grounded plug, making sure that the polarity is correct.

brass_lamp

Even if the neutral and hot wires are correctly connected, a shock hazard still exists unless exterior metal parts of the appliance are not grounded via a separate ground wire.  Above is a photo of a pretty old brass fixture.  Although the polarity of the two conductors is correct, you will get a vicious shock if you touch this lamp because one of the load wires is frayed and touches the brass case.  The barefoot retiree on a tile floor makes an excellent ground!  If this lamp had the metal parts connected to a grounded outlet, the breaker or GFI would trip.

Since the panel box only came with a load and neutral buses, we added a ground (earth) bus.  We were able to buy a very nice brass ground bus to add to the panel box.  The green ground wire from every circuit is connected to this ground bus.

A ground bus in a panel box

An added ground bus in a panel box.  The 2 #10 AWG wires bond the ground bar to incoming neutral utility conductor at the knife switch.

GROUND FAULT INTERRUPTER CIRCUITS (GFI) also called Residual Current Devices (RCD). GFI protection in mandatory in much of the world but is expensive and not often seen in the Philippines, despite the fact that electrical shocks and electrocution are a common events here.  We’ll write more about this later as we add GFI protection to our system.  In the meantime, keep in mind that ordinary circuit breakers are not intended to protect humans from many of the most common types of shock hazards.   A properly operating breaker is intended to carry loads without tripping, loads which could easily electrocute a human being. Consider, for example, that (depending on the design of the breaker)  a 30 A breaker will take one hour to trip at a current of 40 A.   Circuit breakers protect circuits, GFI devices are designed to sense faults and trip fast enough to prevent fatal shocks.

BRANCH CIRCUITS FOR OUTLETS AND LIGHTS.  Now we can discuss wiring “branch” circuits.  Our house plan called for four lighting circuits, eight outlet circuits and two circuits for our two split air conditioning units.  Three of the outlet circuits are dedicated circuits as required by the electrical code, one for the refrigerator, one for the water pump and one for the washing machine.

We wired our branch circuits using stranded 12 AWG (3.5mm²) THHN conductors for the load and neutral wires and 14 AWG (2.0mm²) for the ground wire. Although this wire is rated to handle 20 amps, we decided to use mostly 15 amp breakers.  A fifteen amp breaker (and a #12 AWG wire) have a nominal capacity of 1,800 Watts on a 120v circuit and 3,450 watts on our 230v system.  If we had used 20amp breakers, our circuits would have a capacity of 4,600.  Using the 15 amp breakers on #12 AWG wire gives us a very considerable margin of safety, but plenty of capacity for any combination of appliances we can imagine on any single circuit.

It was our electrical engineer who specified using stranded rather than solid wire for our branch circuits.  Stranded wire is somewhat easier to work with and stands up to situations where the wire is flexed, better than solid wire.  If you are going to use stranded wire you have to be sure to buy switches and outlets designed for stranded wire.  Stranded wire has a larger diameter than solid wire of the same capacity and therefore will not fit properly into most outlets and switches.  Most (but not all) switches and outlets are labeled as to the type and size of wire they can accommodate. Fortunately, the widely available and excellent Panasonic Wide Series switches and outlets are designated for and work well with stranded wire. We used a mix of Panasonic and Royu outlets.  The Panasonic outlets are much better and much more expensive. Our switches are Panasonic and Anam.  Anam is a mid-priced Korean brand which seems to be of very good quality.  If you are using stranded wire and on a budget, Royu makes a low cost outlet (WD922 and WH922) with screw terminals which works quite well with both solid and stranded wire.

Royu Outlet (receptacle)

Royu Outlet (receptacle)

Mistakenly, we bought Anam switches which were made for solid wire.  Our electricians used them but cut off strands of wire so that they would fit into the switches.  Since we used 12 AWG for our lightly loaded lighting circuits, we have plenty of capacity even with the cut strands.   Perhaps we’ll gradually replace these switches at some point.  We did all of the outlet wiring ourselves using outlets made for stranded wire, so we are confident there are no problems with these.

Outlet labelled for solid wire only

Outlet labelled for solid wire only

stranded_switch_clipped

Photo of switches with cut strands

Panasonic Wide Series - OK with solid or stranded wire

Panasonic Wide Series – OK with solid or stranded wire

These Meiji outlets also worked well with stranded wire

These Meiji outlets also worked well with stranded wire.  We tinned the leads.  The neutral leads should be white not red.  This was just a photo to show the Meiji receptacle

panasonic_royu

The above photo shows the interior construction of a Royu brand outlet (left) and Panasonic brand outlet (right).  The cheaper outlets do not seem to be the same quality but less expensive.  The Panasonic housing and contact are quite a bit heavier.  The Panasonic outlets grip the prongs of the plugs so strongly that we have pulled the outlets out of the wall when trying to remove a plug.  Commercial buildings in Iloilo almost always use Panasonic outlets and switches.

There is lots of poor quality electrical gear sold in the Philippines.  Below is a plug made with brass-plated steel prongs rather than brass.  It does not take long for the prong to start corroding.  The capacity of the circuit will be reduced. This is not a problem restricted to the Philippines.  I have a Leviton brand made in USA outlet I brought with me that has rusty terminal screws.  Corrosion of electrical components in the Philippines is rapid, another reason to buy quality products for your own house.  If you buy a pre-built house in a subdivision, did the developer use good parts?

Rusty plug

Rusty plug with non-polarized blades (prongs).  The quality of electrical parts on offer is generally poor.

CONDUIT. This brings us to the mechanics of running conduit for our branch circuits.  Having a detailed electrical plan is essential.  You’ll be required to have one before you get your building permit,  but, in any case, you’ll want a plan.   If you try to make things up as you go, you’ll probably make a mess of things.

Romex-type (NM) cable (several conductors enclosed in a integral plastic sheath)  is available, but not generally used.  In the Philippines, the branch circuit wires are generally run from panel box to outlet to in plastic conduit.  We used individual load, neutral and ground wires of THHN (Thermoplastic High Heat-resistant Nylon-coated) wire in conduit, which is similar to what is used in commercial installations in the U.S.

When embedded in the floor or block walls, the conduit is 25mm rigid plastic.  In the space above the ceiling, the wires generally run in flexible plastic conduit.   The Philippine system of running conduit in the walls can be pretty horrifying when you first see it. Basically, the house is built without much regard to electrical or plumbing runs.  Then, when it comes time to run wires, channels are hacked into the hollow block to accommodate the electrical conduit.  The house can look pretty massacred before the thick finishing coat covers all construction sins.

We tried to neatly cut the conduit channels into the hollow block using a diamond masonry blade in a 4″ angle grinder.  The end result will be the same but we’ll just feel better at least trying to be neat.  Ideally, conduit runs should be anticipated and conduit should be cast into beams so that the beams do not have to be cut later to accommodate the conduit running to the lighting and ceiling fans above the beams.

Conduit in place before pouring concrete

Conduit in place before pouring concrete

Above: before pouring a tie beam at the top of the wall above the location for the panel box, the workers place eight pieces of electrical conduit through the form for the beam. This will provide a path from the panel box for the circuits in the ceiling, mainly light fixtures and ceiling fans.  Put in more conduit than you think you’ll need.  It’s easy to do before the concrete is poured and very difficult afterwards. We should have used larger conduit.  All of these shown are overstuffed with wires, not an ideal situation.

Conduit cut into hollow block wall

Conduit cut into hollow block wall

Above.  Utility boxes which will contain switches are half buried in the hollow block wall.  Boxes are plastic with brass inserts for the mounting screws.  The walls will be plastered with a smooth 1/2″ to 1″coat of finishing cement which is then painted and forms the final finish for both interior and exterior walls.

Conduit will be imbedded in concrete floor

Conduit will be imbedded in concrete floor

These electrical conduits were buried in the concrete floor.  The genius of this system is that wires can be replaced (if necessary) by pulling them through the conduit embedded in the floors.  For this to work, there can be no shortcuts.  The wide arc conduit elbows must be used.  There are no electrical conduit tees.  The blue-color water system fittings can be used with the electrical conduit, but such use may well defeat the ability to pull new wires as the bends are too sharp to pull through.  These outlet circuits embedded in the concrete floors are quite safe from gnawing rodents.

Flexible conduit in attic

Flexible conduit in attic

These photos show how wiring is installed in the attic or ceiling area.  This wiring feeds ceiling light fixtures, ceiling fans, some outdoor lighting and our split air conditioners.  Wiring is in flexible plastic conduit. The silver protrusions are the tops of recessed lighting.  The four stubs of plastic pipe protruding through the top of the wall now carry coax cable to CCTV cameras at each corner of the house.

Recessed ceiling light fixture

Recessed ceiling light fixture

Except for table lamps, all lighting is recessed, no ceiling fixtures or chandeliers except in the bathrooms. We are very happy with the clean look of the recessed lighting, so many exposed fixures are ugly.

After three years in our house we had two recessed fixtures in our kitchen ceiling fail because mice or rats chewed through the short, thin wire leads powering the recessed lights.  They did not touch the THHN conductors which are in conduit.  Our theory is that a thin layer of grease from the kitchen went up through the recessed fixtures and coated the wires.  This made them attractive to the rodents.  Since our attic and roof structures are all cement board and steel, the fire hazard should be minimal.

We have various circuits running outside the house; weatherproof outlets on the porch, circuits to the bahay kubo bamboo guest house, circuits to lights on the perimeter fence posts, circuits for security lighting, circuits for porch lights, circuits for the carport, circuits for outdoor split air conditioning compressors and so forth.  All of these must be anticipated and conduit leading outside installed before the house floor is poured.

security_light_switches

This panel of switches controls all outdoor lighting; front and rear gate lights, lights at each corner of the house, and sodium vapor lights in the garage (three way) and yard.

Panasonic timer switch for security lights

Panasonic timer switch for security lights

Our outdoor security lights can also be controlled by this Panasonic timer switch which is wired into our panel box.  We bought this industrial duty switch after having a couple of hardware store electronic timer switches fail.  This allows our lights to be on when we get back after dark and to shut them off at dawn, even if we are still sleeping or away from the house.

We installed a 250 Watt high pressure sodium light in our yard. It lights up the whole neighborhood.  Our neighbors who raise corn like it as sometimes miscreants sneak in and steal their corn. Generally we don’t use it, but can if we feel the need.

HP Sodium yard light

HP Sodium yard light

It lights the yard quite well

It lights the yard quite well

HP sodium tunnel fixture

HP sodium tunnel fixture

We installed this 150 Watt high pressure sodium lamp in our garage.  These lamps are made to illuminate highway tunnels.

garage_light_on

Please take time to read the many comments below.  It’s remarkable how little consensus there is, even among those who are knowledgeable about wiring.  Take the information here as hypothesis, not gospel.  We are home owners, not electricians or electrical engineers.  Please feel free to offer comments, suggestions and corrections

Revised June 2016

 

 

 

 

 

Comments (65) Write a comment

  1. Hi Bob, here in our area is also “line to ground” just like in your place. And Can’t find a single pole breaker. If I will use a double pole breaker and just connect together the two terminal of breaker to hot wire so that it it will produce an output of 220v each to two hot bar on panel for branches 2pole breaker, while the neutral will be bond to ground wire will this be ok? Will the breaker will work as single breaker ? Thank you!!!

    Reply

    • Leon,

      I can only share my experience with GE plug-in breakers. A double pole breaker will definately NOT serve as two single pole breakers. My theory was that a double pole breaker was just two single pole breakers attached together. I was very wrong and ended up with totally unprotected circuits. I had to rewire my panel box using the DP breakers — one side neutral, one side load. Since the poles are physically linked, a fault will disconnect load and neutral simultaneously. If I had it to do over again, I’d use a bolt in panel box, not plug in. Plug in SP breakers are available. Good luck. Bob and Carol

      Reply

      • So how about the Grounding and bonding? How you bond the neutral and ground in main panel when one side is load and the other is neutral in breaker? Thanks

        Reply

        • Leon, maybe others can comment, but in my panel box the load goes to one leg of the DP breakers and the utility neutral goes to the the other leg. I have a separate ground bus. All of my outlets accept three prong plug, load, neutral and ground. The ground is two brass clamps on the house rebar. Consider this from http://www.esgroundingsolutions.com/why-do-you-have-to-bond-the-neutral-and-the-ground-wire-in-the-main-panel/

          “To visualize the reason why the neutral-to-ground bond is required, you must consider the entire electrical circuit from a 120-volt outlet all the way back to the utility transformer hanging out on the pole:

          In a properly designed circuit, if a fault were to occur on the 120-volt outlet between the hot-wire and the ground, the current will flow through ground wire back to the main panel, where it will move to the neutral wire via the neutral-to-ground bond, up to the utility transformer, back down the hot wire to the circuit breaker, tripping the breaker.
          In an faulty designed circuit, if a fault were to occur on the 120-volt outlet between the hot-wire and the ground, the current will flow through ground wire back to the main panel, where because it does not have a neutral-to-ground bond, the current will be forced through the ground rod, into and across the earth, and up the utility ground rod and in to the utility transformer, back down the hot wire to the circuit breaker. The resistance of the earth is almost always to great to allow sufficient current flow to trip the breaker, and you end up with a steady-state ground fault, that never trips the breaker, and this is a hazardous situation indeed. You cannot use the earth as a conductor.”

          Reply

  2. Hi,

    Aside from Green and Green with Yellow stripes, Any other color permitted by PEC for Grounding?

    Reply

  3. Hello Bob and Carol,

    I am very amazed how you’d find time in putting all of these issues together. Very helpful though. I was born, raised and finished my schooling and a licensed/registered Electrical Engineer (from MIT) there in the Philippines. Now I am residing in the US for almost half of my life. To be honest I was very much entertained because I thought everything about residential and commercial wiring there are done without due regard in complying with the code. Problem is they mixed both European and US standards and make it their own code. I have studied most electrical systems in various countries and I definitely convinced that the US standards is the best and efficient electrical system wiring. GROUNDING System is the one they’ve neglected and mostly disregarded – a system where it’s designed to protect the safety of people and property. No proper implementation because of corrupt practices and most of the houses there are not insured anyway that is why the city officials are not being pushed to implement all requirements necessary for building safety.

    Reply

    • The Philippines is in some ways the most libertarian of places. You can do more or less what you want and live with the consequences. Yes, they make you get building permits, have plans etc. but that is mainly to collect fees. I don’t anyone cares what you build.

      Reply

  4. Hi Bob, outlet is oriented horizontally, it’s because of human safety. As you noticed, MOST power outlets are of different hole size. Larger hole shall be placed above the smaller hole and its terminal shall be connected to ground line and place the live or hot line on the smaller hole below… The essence is that there is a tendency of a suspended cord to expose the upper part of the plug along the way due to the influence of a downward GRAVITITIONAL pulling. Assuming that the orientation and placement of the outlet is correct, in time the upper part of the plug connecting the outlet is exposed, you cannot be electrocuted the ground terminal of the outlet is connected to system utility ground line which is zero potential. For other concern, please see face book page “electrical safety, protection & energy savings”.

    Reply

    • Emilio, thank you for your contribution. What you say makes sense. However, I rarely see grounded outlets in the Philippines. Bob and Carol

      Reply

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  6. Great site and wished i had come across it earlier , as it would have saved me a lot of research into the 3 wire system , and also a few jolts in the house in Manila . I have worked on the 240v two system in Negros and rewired a house down there for a relation . The components for the 2 wire system i purchased from the UK and brought everything up to the 17th edition UK standard which is very safe and gives peace of mind .
    Thanks again for the site .

    Reply

  7. Bob,

    I just want to know if what would be an ideal duration for an ordinary household electrical installation be rewired/re-installed?

    Thanks…

    Reply

    • I am not sure if there is a good single answer to this question. I the U.S. we still see old knob and tube wiring. Many older systems were not intended for today’s higher wattage appliances such as air conditioning and electric hot water systems. I suppose the best thing to do is to examine the physical condition of the wiring and see if it’s okay and then consider if the capacity is still suitable for the anticipated loads.

      Bob

      Reply

  8. Thank you for such an informative website and sharing your experiences with us. I am a retired electrical contractor/master electrician from Texas. I’ve built and remodeled many homes so it is very interesting to learn the Philippine way of construction from someone who has “done the time”.

    I will say that bringing my 120v power tools and voltage inverter was a good decision. The tools here are very expensive. I brought about 10 power tools and will use them on our house improvements so I don’t mind lugging around the inverter.

    Keep up the good work,
    Mike

    Reply

  9. hello guys..

    ahmm anybody knows how much it cost for an electrician to install per outlet, lighting’s, appliances and etc, here in cebu.. or is there a book published about costing per installations? thank you..

    Reply

  10. Hi Bob,

    I live in Angeles City and I’ve recently purchased a ELEMAX with a rated 5.6kva and 6.5kva max power. I didn’t really want to purchase this much power but it was the only Japanese made/honda powered genset we could find around here. After seeing your WEIMA and the price, I think I might have spent way too much. I can only hope it at least is reliable. I was originally going to use extension cords but since I bought all this extra power I now want to get a knife switch like you and wire it in. Unfortunately, it comes with two 16A receptacles which doesn’t give me the full power out of either. So it looks like I will need to either wire directly or replace it with a L6-30R. The schematics seems to show that it’s just a 230V live and neutral so it shouldn’t be a problem to replace the existing.

    My real question is what do we do with the ground from the generator? Since it’s only two wires going to the DPDT. Do we leave the ground connected to the generator as is? I think I’ve read else where and maybe even here that you should not do that. Also does the polarity matter when connecting to the DPDT, how do you know which is correct?

    I plan to have a “electrician” do this work but as you probably know, a lot of the people around here don’t even know what they are talking about. So I want to have my facts straight before trying that.

    Please help asap! Thanks.

    Reply

    • Jack,

      I do suggest you consult with a local electrical engineer familiar with generator hookups. It’s my understanding that the generator neutral should be bonded to ground in the panel box, so your hot and neutral wires from your generator would go through the knife switch and the ground will be a separate wire from the generator to the panel box ground. But, please confirm this with someone who knows what they are doing!

      Bob

      Reply

      • Thanks, I’m looking in my panel box and I don’t really see any kind of grounding at all! I’d hope that’s not the case but it wouldn’t surprise me. They don’t do anything right here and this is a major builder in the area. So now I’d really have no idea where to connect it.

        Reply

        • Hi Jack,

          I am not sure what kind of distribution system they have in Angeles City – 2 wire (230+neutral) or 3 wire (110+110+neutral)? I’m assuming you don’t have grounded outlets (receptacles). That’s pretty common. So you don’t have a ground (earth) at your residence such a grounding rod? If not, they are relying on the utility system ground, say a ground road at the nearest utility pole. I am no expert, but you should have your own ground. You can add a ground bus bar to your panel box and connect it with a heavy wire to a ground rod driven into the earth. Again, I suggest, for the generator hook-up that you consult and electrical engineer.

          Bob

          Reply

  11. hi like to know can australia 3 pin be used for cebu city philippines since this is different to there as they use 2 pins as we building a house there soon thx

    Reply

    • Darren,

      I looked up the Australian plug. Are you planning on bringing Oz appliances to the Philippines? Philippines is 240v/60 cycle whereas Australia is 240v/50 cycle.
      Better just buy what appliances you need here in the Philippines.

      We suggest you wire your new house using U.S. style grounded outlets. See attached image. These are widely used in the Philippines. http://en.wikipedia.org/wiki/File:Domestic_AC_Type_B_USA.jpg

      Bob

      Reply

  12. Hi Bob
    It’s been a while but I have just reviewed your very informative house building blog, with special reference to the electrical wiring, as I am now fast approaching wiring my own home on Negros Occidental.
    A few things have come to note. You have removed that very informative wiring diagram which links up the generator, 100A switch and circuit breaker box. Any chance of reinstating it?
    You also show the clamp which holds the earthing wire to a rebar at the top of one of your posts. Does the fact that the rebar is actually painted make any difference?
    One last point – you used #12 AWG wire, which you say is rated at 20 amps, but several sites on the internet rate it at 9.2 amps, which is quite a difference.
    But overall, thanks again for the effort of posting this very helpful site.
    Thanks
    John

    Reply

    • John,

      Regarding the wiring diagram, we have taken it down for revision. The diagram showed the our generator as providing two 115v hot wires whereas in actuality the generator output is one 230v hot and one neutral. These are still connected to the knife switch in the same way except that we are advised that the generator neutral must be bonded to ground in the panel box, in the same way that the utility neutral is bonded to ground in the panel box. There are also some other changes due to the fact that we have changed from single pole breakers to double pole breakers. I can’t guarantee that my drawing skills will be as good as the original!

      Please read over the many revisions to our essay on wiring.

      Here is a link to an allowable ampacity table for wire: http://www.usawire-cable.com/pdfs/NEC%20AMPACITIES.pdf

      The capacity of wire depends on the size of the conductors and the type of insulation used. We used THHN insulated 3.5mm stranded copper wire. This insulation is rated as suitable for hot and wet conditions. The chart gives an allowable ampacity of 30 amps. Codes (Philippine and U.S.) require using up to 80% of the ampacity, so 12 AWG/3.5mm THHN can be used for circuits up to 24 amps. These ampacities can be further reduced if they are used in areas of high ambient temperature, such a Philippine attic. Even assuming high ambient temperatures, this wire is good for more than 20 amps. We are now using all GE 15 amp breakers with all our circuits so we feel we have a very safe arrangement. Not sure where the 9.2 amps capacity came from but using 20 amp breakers for #12 wire has been the case for decades.

      Others have pointed out the possible problem with the painted rebar used as a grounding point. When I installed the clamp, I did scrape away the paint under the clamp but go to the attic with my angle grinder and then take a photo which shows a better contact with the rebar.

      Bob and Carol

      Reply

  13. Well, i take your advice at heart,,, however,, i have a friend who is American, married to Philippino, the built a new home, and they put both 110 and 220, also they are planning to bring appliances, such a refrigerator, freezer, washer and dryer, along when they transfer to the philippines… This is why i am asking the question of bringing my own appliances, small and large,,, another reason and the biggest,,, is that philippine appliances small or large do not withstand what US products do…. I have learned my lesson, for i have been married to my wife for 13 years, and have communicated and been there, first time 1992, second 1994, third 1999, fourth 2007.. anyway i am grateful for your input.. and Thanks for the advice…. however,, i feel that with good electrical outlets, switches, wiring, breaker box and breakers…. My wife and I have purchased some land already, now we need to build a house,, and i am looking for any advice i can find…. Thank you so very much, and Please advice me more.. for i am planning to go to the Philippines this coming November and start to look for all things needed to build a house… and therefore i greatly appreciate all advice i can get….. Larry

    Reply

    • Larry,

      Top quality large and small appliances as well as electrical gear are available in the Philippines. Our Electrolux refrigerator is the best quality I have ever owned as is our Bompani kitchen range. The same is true of electrical gear including outlet and switches. Admittedly, the best stuff is found in the cities and it is going to cost more than it would in the U.S. However, keep in mind that it will not require step-down transformers and parts and service will be available in the Philippines.

      There is no definite rule about these things. There is nothing wrong with bringing all your stuff from the U.S. We brought a KitchenAid food processor, a Braun blender, a Sunbeam mixer, a Singer sewing machine and various table lamps. Perhaps you should bring the things you already own that are of good quality and in good condition but don’t go out and buy U.S. stuff just because you think good quality is not available in the Philippines.

      Whatever your decision, I’m sure you’ll enjoy your Philippine life.

      Bob and Carol

      Reply

      • Bob and Carol,

        Thanks for your advise,, one thing more if i may ask,,, can it be done without much problem, that is wiring of 110 and 220 separately from the same breaker box, as can be done here in the USA??

        Reply

        • No, except for a few places, there is no easy way to have 110 v. In the U.S. the utilities provide two 110 volt hot wires which, combined, can give you 220. Here (and most of the rest of the world) you get one 230 volt hot wire. If you bring some 110 volt small appliances, you can use a step-down transformer to run them.

          Bob

          Reply

  14. Would it behove me to bring my own electrical outlets, and switches, also my own electrical box and breakers?? Also could i bring along my own appliances? and perhaps my own wire?

    Reply

    • Larry,

      Thanks for your comment. I would buy all the electrical gear in the Philippines, but especially breakers. If you bring the inexpensive switches and outlets from the U.S. they will be rated with use on 115v systems. Our own Philippine utility delivers more like 250v. I did bring some 12-3 Romex cable and I did use in on conduit to an outdoor circuit. Most wiring here uses individual wires in conduit, not the Romex type cable which are stapled to studs in the U.S. Are you going to use a Philippine electrician and ask him to install 115v rated gear? He might refuse. The electrical inspector might not give you a COA, especially if he saw non-standard switches and outlet around the house. The electrical gear here is good, if you avoid the cheap junk. We used Panasonic, which is great stuff, Anam, Korean and good quality and even Bticino, an Italian brand.

      Based on your question about appliances, I revised the electrical post to try to answer that question, saying, “Many Americans considering a move to the Philippines want to know is they can get 115 v power in the Philippines and whether or not they should bring their 115 v appliances with them. If your residence has the two-wire 230v system, 115 v is not going to be available except by means of a step-down transformer. Step down transformers generate heat and waste power, but are quite popular in the Philippines and available in almost all hardware stores. There is no right answer to the question about bringing appliances from the U.S. to the Philippines. Items used only infrequently, say a food processor or sewing machine, it might make sense to bring. Items which are in constant use, such as a refrigerator, we would not bring. We have seen Filipinos using 115 v power tools, dragging around a step-down transformer. Bob sold his power tools before leaving the U.S. and bought new ones in the Philippines. His main regret is not bringing his Delta table saw. It happened to have a 115/230 v motor. Just remember that electrical plugs in the U.S. and the Philippines look the same, but the first time you plug your 115v gadget into a 230 circuit, will likely be the end of that item.

      Some expats have bought and installed their own power pole transformers and have been able to get 115 v that way. This is an expensive option, probably more expensive than buying new 230 appliances.”

      Best wishes,

      Bob and Carol

      Reply

  15. Here’s an informative essay on Philippine electrical systems reprinted by permission of its author Harry Morgan. As you read what we have written above, you will see that we have diverged from Mr. Morgan on the matter of breakers on the neutral line. We would also be careful in using 110v breakers from the U.S. Some are rated 110/220v, marginal on our 246v supply, some are for 110v only.

    Harry wrote:

    Dear Members,

    Personally I enjoy the arguments about the electric service in the Philippines. I’ve been an electrician for 30+ years in the USA and I totally rewired my father-in-law’s house in Sibonga, Cebu. I will try to address some of the issues about the electric service you will find in most of the Philippines, although I understand there are small areas of American style systems around the old US military bases.

    “IDEALLY”, here is what you “should” have in the majority of the Philippines: A transformer on a pole somewhere near your house, it will be serving several houses in the neighborhood. It will have 2 lugs on the secondary with 220 volts between them. There will be 1 wire from each lug going to each house. One and only one of the lugs “should” also have a second bare copper wire connected to it with the other wire and this bare wire will run down the pole to a ground rod at the base of the pole. The 2 large wires running to each house (service drop) will have the hot wire insulated and the other (neutral) may be bare or insulated. After passing through the electric meter these wires go to your fuse or breaker box. The hot wire will connect to the supply buss where the fuses or breakers are. The neutral wire will connect to the neutral bus which is directly mounted to the metal box. There SHOULD also be a bare wire going from the neutral bus to a copper ground rod at each house. From the fuse or breaker box there will be one black 220 volt hot wire from the fuse or breaker and one white neutral wire from the neutral bus for each circuit. This is what you should have in the majority of the simple Philippine 2 wire systems, please take note of the above IDEALLY’s and SHOULD’s.

    The Philippine system is a GROUNDED system because the neutral wire is/SHOULD be connected to a ground rod at the pole where the transformer is and a ground rod and/or cold water pipe at each house. This keeps the transformer secondary from floating: the neutral wire at zero volts and the hot wire about 220 volts, depending on the service company’s supply voltage. The neutral wire will be at zero volts because it is connected to ground. If you have anything other than zero volts, you have a loose, dirty, or missing connection to the ground rod; or you are using your volt meter incorrectly (which is not unusual). The neutral wire is also called the “GROUNDED” wire and it should have white insulation throughout the house.

    AS for the 3rd green or bare wire, which is missing most of the time in the Philippines, It is called the “GROUNDING” wire. It is connected to the neutral wire in the fuse/breaker box either in the same neutral bus mounted to the metal box or a seperate GROUNDING bus, but they should be connected together and only in the fuse/breaker box, this is the one and only time they should ever be connected together. Throughout the house this GROUNDING wire should connect to the 3rd round prong of each recepticle, all metal electric switch/ recepticle boxes, green hex head GROUNDING screws, and eventually all metal fromes of all electric appliances. This keeps the metal parts of the electric system and appliances at zero volts. The same Zero volts your human body is, so no shocks.

    Throughout the house the white GROUNDED wire is at zero volts and is a current carrying part of each circuit. The green or bare GROUNDING wire is also at zero volts, is not part of the circuit, and does not carry current (except in a fault). It’s purpose is to keep all metal parts of the system and metal parts of the appliances at zero volts, and to trip the breaker or blow the fuse and shut the circuit down in the case of a fault.


    As for fuses or breakers, there should be one, and only one, in each circuit and it should be in the hot wire. There should NEVER be a fuse or breaker in the neutral white GROUNDED wire, usually you will find this mistake in the old 2 fuse boxes. I have seen a fuse in the neutral a lot in the Philippines and some old installations in the US. If you find a fuse in the neutral GROUNDED wire, please remove it and connect the neutral GROUNDED wire direct. If you disagree with me and that fuse in the neutral ever blows, you may then understand why.

    There is no magic electrical trick you can do to get 110 volts from the usual Philippine style 220 volt electric system. The ONLY way is to buy a 220 to 110 volt transformer.

    Yes you can ship an American style breaker box to the Philippines and it will work fine, if you know what to do. The 2 hot busses will have to be connected together and tied to the one hot 220 volt wire in the Philippines. Yes, standard American single pole 110 volt breakers will work just fine on Philippine 220 volt systems, they are good to 300 volts. You will only need single pole breakers, NO/NONE/NEVER any 2 pole breakers. Also the same breaker on 220 volts will carry twice the power it carries on 110 volts. A 15 amp breaker carries only 1650 watts on 110 volts, but a whopping 3300 watts on 220 volts. So you will likely want/need the smallest breakers you can find.

    I have no idea if an American style 110 volt ground fault or arc fault breakers will work on the Philippine system, I imagine you would blow the test button when you try to test them. I contacted the American manufacturer with this question, but they wouldn’t answer. I imagine because of legal issues. You will have no use for the American style 2 pole GFCI’s for you hot tub heater, I imagine no use for a hot tub either.

    Now for the American style 110/220 volt system you might find around the old US military bases: The transformer on the pole will have 3 lugs for the secondary. The middle lug is the “center tap” and will be connected to the ground rod that should be at the bottom of the pole and at the ground rod that should be at each house. The second wire connected to this lug and running to each house may be called GROUNDED, neutral, or common. The other 2 lugs are the hot wires. Each hot wire will be 110 volts to the neutral/common/GROUNDED wire. And there will be also be 220 volts between the 2 hot wires if you leave the 3rd neutral/common/GROUNDED wire out of the circuit. The American style system is a single phase system even though there are 2 hot wires. One hot wire will be at +110 volts at exactly the same time the other hot wire is at -110 volts, thus they are in the same phase.

    If there are any budding electrical engineers out there, please no arguments about American style 208 volt systems, I already know they use 2 phases from a three phase system. If you do have a 3 phase system for the secondary in your area of the Philippines, I think you will find it to be a 380 volt 3 phase “Y” tied secondary. Thus any phase to ground will be 220 volts. Besides, I thought engineers were supposed to drive trains?

    If I can be of help or if anyone wants to argue (I enjoy both), you may contact me on or of the list.

    Best always, Harry Morgan harry80020@yahoo.com

    Reply

  16. You can buy books on electrical wiring at National Bookstore or better get a copy of the Philippine Electrical Code. This is from a comment posted on the blog.

    Bob,

    Below is the IIEE web address and contact numbers. You may call them up about the purchase then they will tell how much including shipping and ask you to deposit it with their bank account (BDO). You have to scan the receipt and email it to them for confirmation of the purchase. The item/s will be shipped on the same day thru LBC if scanned receipt is received before 2PM. You will receive the item/s the next day or the day after depending on your location.

    http://www.iiee.org.ph/home/index.php/home/contact-us

    I hope this one may help you get a copy of the code.

    Happy New Year!

    Jahn

    Reply

  17. I have written over 50 books on electrical and after readers various comments I would like to say: Grounding to concrete encased rebar is the BEST ground and the worst is a ground rod!
    As far as connecting wires, the Code states in 110.3(B) all electrical equipment shall be installed as LISTED! The proper electrical connection requires an inch-pound torque. The label in the load center will state the correct inch-pounds for the wire size. All circuit breakers in the U.S. have the required inch-pound of torque molded into the circuit breaker case. How many of your so called electricians even have a torque screwdriver? In you reply ask them.
    I work as an electrical expert in personal injury and death cases, and when the lawyer asks you if you torqued the connections you had better hope you did! Please understand the Philippine Code and the NFPA 70 contain the same rules and Code rules are the MINIMUM requirement and a jury doesn’t want to hear you didn’t even follow the MINIMUM! Read 110.3(B) before you connect another electrical conductor. And by way the way in section 110 the Code considers concrete to be a GROUNDED material, you can inform your reader.
    Tom Henry
    56 years in the electrical industry and many visits to the Philippines
    National Bookstore sold my books

    Reply

    • Tom,

      Thanks for your comments and for your backup on using rebar for grounding. There are lots of folks out there who feel that the only acceptable ground in a grounding rod or pipe.

      I have never seen an electrician with a torque screwdriver but the idea makes sense to me. Under-tighten and have bad connection, over-tighten and break something.

      Bob

      Reply

  18. Just a comment regarding the use of 2-pole circuit breakers. It is perfectly OK to use these on a 220V AC single phase system. If a RCD is used these should be 2 pole. Also though not applicable for residential houses, it is mandatory to break both the phase and neutral of power suppies into harardous areas. In all cases the phase and neutral of the 2 pole circuit breaker must be mechanically linked. Under no circumstances should a fuse be placed in the neutral or an independent circuit breaker.

    Reply

  19. Hi Bob,
    Doing my electrics now and you are right about Panasonic sockets, they are much better than the Royu. Would have preferred the international sockets for flat and round connectors but the ones I saw had no protective spring covers inside which left gaping holes where the bare terminals could be seen. Have decided to use the ordinary slot type by Panasonic. The latter are also the only brand I found to have screw type terminals. The other brands are the spring type which are pushed back by a narrow blade and then they come back and trap the wire inside. This is fine for lamp sockets but Power sockets at 10 amps …..doubt that, would prefer a screw that can tighten into stranded cable to make more electrical surface contact.
    Some very nice distributor/fuse boxes available now instead of the dull grey jobs that you hide under the stairs. These are attractive plastic fronts with rows of trips under a clear cover; they don’t look untowards on the wall by the kitchen door. I was disappointed to find the lowest trip to be 16 amps. In the UK a lighting socket will have a 6amp line and we have trips to suit. My architect has put 8 lights on a 16 amp trip …imagine a load of maybe 800 watts at the most, drawing less than 4 amps protected by 16 amp fuse yuk yuk. At first the plans specified 3.5 mm all round and I wanted a smaller cable for the lights but the 2mm suggested by my electrician will only carry about 9 amps, even covered by insulation and in a pipe at 30 odd degrees! I can see the benefit of using 3.5 mm on the light circuits since if there is a problem we can get the surge of shorting current to the 16 amp trip asap. The 3.5 mm wire fits perfectly into the Panasonic sockets. Panasonic also do a double socket linked together needing only 2 connections and it also has the 3 pin type for the ground connection. (285 pesos, 2 times the Royu ones)
    My plans also have too many trips to cover what I think is a very low load and I have put all the lights under one 16 amp trip and also the power sockets under another 16 amp trip. Electricity is expensive in the Philippines and no one user’s high wattage appliances save a iron at less than a kilo watt.
    My electrician arrived this morning to “layout” the Meltex piping into to rebar grid of the first floor slab before the pour, apparently in the PI it’s the norm. I sent him home because I prefer to put a 17 inch ½ pipe into each beam to string the cable through and lay the wire onto the ceiling. My foremen will put a ¾ piece of marine ply in the centre of the room suspended by 10mm rebar from the first floor to hold the room lights, so we can also use it to support the junction boxes…….or Johnson boxes as my man says hohoho.
    Ground or Earth rod will go down the side of our septic tank to the damp parts that will never dry out even in the summer season. I can feed it alongside the plastic sewer pipe to the building distributor boxes..
    Some difference in the quality of “back” boxes and “junction” boxes, ended up with “omni” at 20 pesos from Ace hardware, 5 pesos more than el cheapo but worth it.
    Said to my foreman…water goes up and electric comes down. These local chaps love to hide services under concrete whilst we are used to having them exposed and more accessible.
    take care..Peter
    ps we are having our light switches horizontal with “down” for “on”

    Reply

    • Thanks for your excellent report. When I do my list of things I’d do differently, using all Panasonic outlets and switches will be on it. Great stuff. Also I’d use all 15a GE breakers.

      One engineer commented that the spring type terminals are better. Over time the wire flows or flattens. With screws the connection can then loosen, but the spring connectors maintain firm contact. But, I agree that the screw terminals FEEL more secure.

      Bob and Carol

      Reply

  20. Hi, I have a second home in Pampanga, I shipped in a GE 20 Circuit Panel Box with all GE Style breakers installed and converted my second home there to US NEMA standards I also shipped in all wires and conduit pipe because I did not trust any of their low standard and poor quality electrical items. I also seen the snickering by the so-called electricians there but when I was done they simply dropped their collective jaws in awe and I had a line of electrician wannabes lining my driveway. I wanted a 120/240v Delta power because of my imported US appliances from the skinny toothpick pole so I found a used pole transformer here on Guam for cheap and had the local power company in the PI install it and at first they had reservations and said so but I simply said I am donating it to their company and they couldn’t climb the pole fast enough. I have seen through my years here on Guam a certain amount of Filipinos shipping all sorts of electrical items via Forex shipping for a very reasonable price and I looked into it and I saved a lot of $$$ sending all my electrical appliances and TV’s from the local K-Mart and Home Depot as compared to the prices in the malls in the PI.

    Reply

  21. Bob,

    The PEC requires the use of 3.5 sq. mm as minimum wire size for power circuits provided the connected load does not exceed 3680VA. You may use 2.0 sq. mm as minimum wire size only for lighting provided the load does not exceed 2760VA. Overcurrent protection shall not exceed 15AT and 20AT for 2.0 and 3.5 sq. mm, respectively.

    Power outlets shall be calculated at no less than 180VA per box while lighting outlets shall be calculated at a minimum 100VA per outlet. So, a 3.5 sq. mm wire can have 20 maximum power outlets and 27 lighting outlets for the 2.0 sq. mm wire.

    Jahn, REE

    Reply

  22. Hi Bob,
    I have some concern on the service entrance of the house. Is the metal conduit that housed the service entrance cable and runs inside the attic connected to the ground? Is there a service switch or service disconnect installed outside after the meter? If there is none, the service entrance cable from the meter running inside the attic is not protected by a breaker or safety switch. It will looks like a utility company erected its additional pole in the open space inside the house. The service entrance should not be ran horizontally in the attic but should instead run vertically concealed inside the concrete wall unless it is buried in a concrete slab. The metal conduit which housed the main supply cable should be used up to the service panel where it will be bonded galvanically to the frame.

    Regards,

    Andrei
    Orl,FL

    Reply

    • Hi Andrei,

      You are the second person to question the installation of the service cable in the galvanized pipe. The pipe is not grounded except perhaps by passing through the steel cornice components. It should be easy to run a ground wire from the pipe to rebar coming up from the footers. Thanks for pointing this out.

      Bob

      Reply

  23. Pingback: Building our Philippine House – Index | My Philippine Life

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  25. Andrew,

    One other thing. We discussed the neutral to ground jumper in the panel box. I got to thinking that the jumper means that when the generator is running the generator neutral will be connected to the utility neutral through the buss. Is there any possible danger to utility workers in this?

    Bob

    Reply

  26. Hi Bob,

    You mentioned beefing up the bonding connection for lightning safety and it piqued my interest. One of these days i hope to be living under a metal roof in the Philippines myself. I’ve been reading up on metal roofs and lightning protection. I thought you and other readers of the blog might like to know what i found so far.

    Grounding the metal roof is not required by code except in the unlikely event that your roof is likely to be “energized” ( gets touched by a hot wire). But most people think that grounding the roof can’t hurt and might be beneficial. But grounding the roof might require running a bonding conductor to each panel if they have an insulating coating.

    In your house, the roof panels might not be electrically connected to ground, but the giant metal roof trusses are likely grounded due to the welded connection to the rebar from the top of the wall (provided the wall rebar is tied to the foundation rebar).

    No matter how big the grounding wire is in your main panel, it isn’t going to help you much in a direct lightning strike on your house. But it will help if lightning strikes in the neighborhood and induces a surge on the service entrance conductors. What will help even more is a whole-house surge suppresor (Transient Voltage Surge Suppressor-TVSS). I installed one in my main panel that looks like a double-pole breaker. If there is no room for another breaker a unit like this can be used: http://74.53.140.226/~sycomsur/products/SYC_120_240_T2-4-3.html

    If you want to protect the house from a direct lightning strike, it can be done with a separate system of lightning rods, ground rods, and heavy conductors to connect the two. The code for lightning protection is published by the same people who publish the NEC, and i found a downloadable copy here: http://www.atmo.arizona.edu/students/courselinks/spring07/atmo589/articles/NFPA_780_2004.pdf

    And here is a helpful guide for designing a lightning protection system: http://www.designandbuildwithmetal.com/TechArticles/Articles/lightning_protection_basics.aspx

    For a typical Philippine house with metal roof trusses, it should be possible to use the roof trusses as conductors in the lightning protection system. That would reduce the amount of heavy conductor required to just between the ground rods and the roof truss.

    Although the lightning protection code allows using rebar in a concrete foundation as a grounding terminal in new construction, i think it would be much better in a typical Philippine home to use dedicated ground rods instead. If lightning hits my house, i’d much rather have the millions of amps going through a thick braided copper conductor on the outside of the wall instead of through the rebar inside of the wall. FYI: some experts recommend staying away from walls containing rebar during a thunderstorm (and also stay away from computers, wired phones, metal plumbing, and metal framing around windows and doors).

    Cheers!
    -Andrew

    Reply

  27. Hi Bob and Carol,

    I managed to find a free download of the Philippine Electrical Code in PDF format. The name of the file includes “2008” and “Draft”. Even if this document is not the one currently in effect, it’s probably not much different from the one that is in effect. Here is the link:

    http://rapidshare.com/#!download|755l33|263242134|Philippine_Electrical_Code__Draft__2008.pdf|6248

    I just found it and have not had much time to read it, but it does not appear to have a table of ampacities just for service entrance cables as the NEC does. If so, then the #2 wires you used might be the legal minimum for a 100-amp service. Those who snickered at your “oversized” wires just aren’t used to seeing people follow the code. 🙂

    Also, using rebar for a grounding system electrode is allowed in the PEC. The text is almost identical to the NEC:

    “2.5.3.3(a)(3) Concrete-Encased Electrode. An electrode encased by at least 50 mm of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 6 000 mm of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm in diameter, or consisting of at least 6 000 mm of bare copper conductor not smaller than 22 mm2. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.”

    Bare rebar like you used is specifically allowed.

    You didn’t say how big your grounding wire was, but i found a table that says it only needs to be 3.2 mm sq for your 30 mm sq service entrance conductors. I think that is around #12 AWG which seems mighty small to me. In the US the wire would have to be at least #8 AWG. In the code this wire is called a GEC or “grounding electrode conductor”. You said you used a #10 AWG wire to bond the ground bus to the neutral bus inside the main panel. Since that is bigger than the minimum size needed for the GEC, it should be fine. If i were wiring the panel i would run the GEC in one continuous, unspliced piece from the rebar clamp through the neutral bus or ground bus and then terminate it on the other zero-potential bus inside the main panel.

    —–

    Hi Bob,

    Congratulations on your new house! I haven’t finished reading the blog yet, but it sounds like you’ve carefully considered all the options and made a lot of smart design decisions. I’m hoping to build a house near Manila in five or ten years and am eager to learn from the experience of others. It’s definitely a challenging situation for people familiar with different methods, materials, and standards of home construction.

    The rebar we use here LOOKS the same as the rebar used in the Philippines. I suspect it is the same, but i’ll have to research that. I’m pretty confident that you have a good ground electrode system. You could have it tested if you were curious. It’s not a simple test, though. You couldn’t do it yourself with a voltmeter. You might be able to get the utility to do it for a fee. Here is more info about ground testing:
    http://ecmweb.com/grounding/electric_ground_testing_techniques/

    In the US the neutral bus and the ground bus are bonded together in the main panel. In all downstream subpanels the neutral bus is isolated from the ground bus. You used a #10 wire to bond these together in your main panel. That is probably adequate. I’ll have to check but i think the NEC would require a bigger wire here in the US.

    When there is a wider prong on a plug, it is supposed to be connected to the neutral and the other prong goes to hot. When both prongs are the same it shouldn’t matter because the device is supposedly “double-insulated”. I can only guess why your stereo cares which way it is plugged in. I’ll bet if you opened it up you’d find the neutral wire goes to the internal chassis ground (if there is one).

    #2 for service entrance cable might have been overkill, but #6 would definitely be underkill. Like you i prefer to err on the side of caution and safety. I would not worry about your service entrance conductor overheating, although the conduit is small, the conductors are over-sized and should not get very warm.

    Crimps make good connections. If you taped them very well, it should be good for decades. But twisted and taped connections will fail over time. They are explicitly forbidden in the NEC. I have seen with my own eyes wires twisted together years earlier that no longer have electrical contact due to surface corrosion. Before the connection fails it becomes a high-resistance connection which can easily lead to fires. Yikes!

    Wire nuts are great for solid wire. I don’t have much experience with them on #12 stranded wire. I’ll have to research that.

    You might want to wait a year and then examine the stranded wiring connection to one of your heavily-used receptacles. If the periodic heating and cooling has not caused the connection to loosen up and start to burn, then it will probably be good for decades.

    The last time i was in the Philippines was three years ago. I was able to get a copy of the National Building Code of the Philippines in a bookstore in Manila (i think it was a branch of the National chain). But the Philippine Electrical Code eluded me and i looked all over.

    I’m looking forward to reading the rest of your blog and finding out what you like about the new house and would you would have done differently (if anything). Cheers!

    Reply

  28. You wrote: “We discovered that our electricians would sometimes cut off strands from the 12 AWG wires so they would fit more easily into switch terminals.”

    Bad electricians, no donut for you! Did you really use stranded wire for all the 15-amp and 20-amp circuits? I wonder if that is common in the Philippines? It’s a little bit easier to pull stranded wire through conduit compared to solid wire, but using solid wire makes it much easier to make connections from wire to wire and wire to screw terminal.

    In the US the most common receptacles and switches are designed for solid wires only (which doesn’t stop some people from using stranded wire). I wonder if the wiring devices you have in the Philippines are more stranded-friendly than wiring devices here in the US.

    Reply

    • We are advised that using the stranded is better than solid copper wires. I had solid copper wires installed in one of our houses in metro Manila and after 12 years, the copper got brittle and we had problems pulling them out.

      Reply

  29. “To run the main feed into the attic we used 3/4? galvanized pipe.”

    I hope you used electrical conduit and not galvanized water pipe. Galvanized water pipe should not be substituted for electrical conduit because the galvanization causes the inside to be rough enough to damage the insulation of conductors pulled through it.

    Also, 3/4 inch is too small to meet NEC requirements. According to table 1 in annex C, the conduit should be at least 1 inch for two or three #2 conductors. In the US the smallest service entrance conduit commonly used is 1-1/4 inch.

    Reply

  30. “It’s interesting that our entrance cable (weather head to panel box) is #2 AWG copper (as specified by our electrical engineer) while the cable from the pole to the house is much lower capacity #6 AWG aluminum.”

    According to the NEC table 310.15(B)(6), #2 AWG copper can be used for a 125 amp service. For a 100 amp service you could have gone with the smaller #4 AWG copper wire. Your engineer may have mistakenly relied on table 310.16 for general-purpose use that requires bigger wires for a given amp rating.

    Utilities everywhere use small wires when connecting overhead services. They can do it because the wires are in open air and not near anything combustible, so it doesn’t matter if the current warms them up a little from time to time.

    Reply

  31. Mabuhay! I’ve read half your blog and so far i love it. I’m planning to build a house in the Philippines someday, and i’m sure the info here will be very useful.

    If i understood your description correctly, you may have a perfectly adequate grounding system for your electrical service. You wrote:

    “Rather than using a grounding rod pounded into the soil, we attached a copper clamp to the rebar in one of the house’s main columns. This rebar leads about 1.5 meters underground to a mass of rebar in the base of the footer. A heavy copper cable runs from the clamp to the panel box. ”

    Where i live in California, using the rebar in a concrete foundation as a ground instead of a driven ground rod is allowed by the National Electric Code (NEC) and is also quite common. My house built in 1984 uses rebar instead of a ground rod. A new house i’m helping build right now is the same way. Both were approved by the local building inspector.

    The NEC requires what it calls a “grounding electrode system” installed where the electric service enters the building. That system is composed of one or more “electrodes” and a wire that connects the electrode or electrodes to the main panel. A driven ground rod is one permissible type of electrode. Rebar can also be permissible if installed correctly. Here is what the 2008 NEC says about it:

    “NEC 250.52(3) An electrode encased by at least 2 inches of concrete, located horizontally near the bottom or vertically, and within that portion of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 20 feet of one or more bar or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 1/2 inch diameter.”

    I don’t have a copy of the Philippine Electrical Code, but i believe it is similar to and maybe even derived from the NEC used in the US.

    The customary practice here is to arrange for 6 to 8 inches of rebar stick out of the concrete at a convenient location near the main panel. Then use a purpose-made ground clamp to connect a wire to the rebar and run the wire to the main panel.

    Reply

    • Hi “pogidaga”

      Thanks so much for your comments and compliments about our blog and electrical system. You really seem like you know what you’re talking about. Hopefully you comments will benefit other readers.

      Thanks especially for the information about using rebar as a system ground. I note that the code you quote calls for galvanized or coated rebar. Such rebar is not used in residential construction here, as far as I know.

      As you know, our utility distribution grid uses the “single wire system”. My panel box has a neutral bus which is connected to the utility company ground wire. Our house is next to the utility company’s employee subdivision and not far from a main substation. The utility poles and lines are new and really well done. Each concrete utility pole is well grounded so our utility-provided ground is probably as good as it gets for this type of system in the Philippines. Then I have a ground bus in the panel box which is connected to the footer rebar with a copper clamp. We used grounded outlets throughout so the neutral side of the plug (if the plugs have polarity — many don’t) goes to the utility company ground and the ground side goes to my own rebar ground. I mulled over whether the neutral bus and the ground bus should be connected in the panel box. I did end up joining them with a 5.5mm (10AWG) jumper. My stereo receiver which has a no polarity plug complained until I reversed the plug. Any comments?

      Regarding the entrance cable, I have not been able to get a hold of a copy of the Philippine Electrical Code, despite trying to do so. But I do have a copy of a guidebook for electricians published by Columbia Wire and Cable, one of the big Philippine manufacturers. It gives two charts for allowable ampacities, one for free air and one for raceway or burial. I used 30mm (2.0) THHN/THWN rated for 90C. According to the guidebook, this wire in conduit will handle 120 amps so you are 100% correct. But, evidently the code calls for calculating wire size using 80% of rated capacity. That’s how I came up with 100. Anyway,much of this was new to me and I wanted to err on the side of bigger/better. The electricians and electrical inspectors were amused by the use of the 2.0AWG which they thought was wildly over done. They said I should have used 6 AWG. 6 AWG is rated for 70 amps! Maybe they are right. We just don’t have much load. Our two air con units are 7.82 amps together, our water pump is 500 watts. All lighting is compact fluorescent. No dryer, no electric stove, no hot water heater.

      You are also right about the conduit size. I did use 3/4″ galvanized water pipe to support the weather head, but only a short length, maybe three or four feet. The rest of the way it’s in 30mm plastic conduit. I don’t think chafing will be a problem and the oversize entrance cable should not overheat?

      I’m really guilty on the stranded wire front. All of our wire is stranded. And, you’re correct that many of the available outlets and switches are made for solid wire and the device is stamped that they are for solid wire only. Many have no screw terminals at all, just the push in connectors. There were two brands which seemed to accommodate stranded wires, Panasonic (expensive but good) and Royu (cheaper) so that’s what we used. We used 12 AWG wire, we have lightly loaded circuits and most boxes and conduit are embedded on concrete, so hopefully the stranded wire will be fine.

      It’s interesting to note that wire nuts are not used here. Old fashioned wire to wire splices wrapped in tape is the custom. I used Buchanan copper crimp connectors and a crimper. The splice was then wrapped in tape.

      Thanks again for your contributions.

      Bob and Carol Hammerslag

      Reply

  32. Hi Bob,
    It is difficult to work out whats best for all circumstances. With a big enough generator no problems arise, start the thing going and then switch over. Most of us would probably have a small unit say 3Kw and it would only be used for fridge, tv and lights. Having it wired for when the mains fails gives some thought. We may not be around to choose the breakers to switch off and those to leave on. Putting the gen on a heavy load will burn out the alternator.
    Possibly an idea would be to have the “emergency” circuits (lights, fridge,tv) on a separate breaker and wired via a changeover switch to the gen set.
    No problems would arise when the switch was operated by an untrained person.
    Peter
    ps I cringed when first seeing the local Filipino electrician twisting the cables to make joins but actually they do hold up well……love the orange toothpaste caps for joining ends together. Screwed terminations WILL work loose.

    Reply

  33. As stated in a previous post I’m still learning about residential construction in the Philippines. Can you please explain (1)why the electrical conduit is buried under the slab rather than vertically in the hollow-core from wall outlets and wall switches to your spacious attic; (2) why you weakened the hollow-core by cutting vertical or horizontal channels instead of installing inside the hollow-core; and (3) why the wall outlet boxes are installed horizontally instead of vertically as in the US? Are the wall outlet boxes installed horizontally because of a safety issue – since the outlet boxes are not typically installed with a ground wire? Thank you.

    Reply

    • Theodore,

      To some degree we just followed Philippine building traditions in the way we did many things.

      Here’s a few thoughts. The hollow cores in hollow block are always filled with rebar and concrete so there really is no cavity. Properly filling the hollow block with concrete and rebar is essential to the strength of the wall as the block themselves are very weak. Yes, channels are cut into the block to accommodate conduit, but then when the wall is finished (plastered with concrete), the conduit is covered over with a material which is certainly stronger than the hollow block which was chipped away. The real problem comes when someone forgets to embed conduit into the posts and beams when they are poured. When this happens, the post or beam can be partially cut to accommodate the conduit. Remember though that the entire wall is plastered so any cuts in structural members are shallow as the conduit is mostly hidden in the cement plaster finishing.

      I’m assuming that outlet wiring is routed through the floors because the path to the panel box is shorter and more direct than if the wires were routed through the attic. I actually like the system. The conduit system, unless shortcut are taken, is such that new wires can be pulled in case of problems. The wires in the conduit in the center of a concrete slab should be pretty well protected from being chewed on by any critter.

      Honestly, I don’t know why my outlets are horizontal rather than vertical. We just think they look better that way. All our outlets are grounded.

      Hope this helps.

      Bob
      http://

      Reply

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