Introduction
Like most other countries, the power coming out on the wall-outlet in the Philippines is significantly different than what comes out of a wall-outlet in the United States. I hope in this day and age, no one is really surprised about that. What is interesting is that depending on what the power company provides to your house, you can, if needed make a wall-outlet compatible with the Untied States. And I am no talking about a step down transformer, though that is another solution. Let me explain.
Power Specifications in the Philippines
Lets start with what is expected by the average user. Power in the Philippines is expected to be delivered as 220 VAC (Volts Alternating Current) at 60 Hz (cycles per second). In the United States household power is expected to be delivered at 110 VAC 60 Hz. The common solution for US appliances is a 2:1 step down transformer, that converts 220 VAC to 110 VAC, with the frequency being maintained at 60 Hz.
How power is delivered in the Philippines
There are two modes of power delivery in the Philippines depending on where you are at. The first is Single Phase 220 VAC 60 Hz. This is the simplest two wire delivery method with a hot and neutral wire. In houses wired like this, a step down transformer is the only viable solution.
Note I am not mentioning ground wires here for those familiar with US electrical codes. And you will find a lot of homes have no ground wires in their outlets and switches. Though the Circuit Breaker Panels usually have grounds. And this is allowed under Philippine electrical codes.
Note also that when looking for a step-down transformer be aware of peak power requirements. Don’t get one based on average power rating. Most of the better step-down transformers are fused, and the peak power power surge from motors and heaters will most likely blow the fuse.
The other way power might be delivered to a house is split phase 220 VAC 60 Hz. Interestingly this is exactly how most homes in the US get their power. It is just wired differently in the Philippines.
Split phase means three wires, two hot wires and a neutral. Each hot wire carries 110 VAC. In the US one wires hot to neutral across outlets providing 110 VAC. In the Philippines outlets are wired with two hot wires, each being 180 degrees out of phase with the other. This provides 220V AC.
If you have split phase power you can actually wire outlets for 110 VAC without a step-down transformer.
Conclusion
I am lucky enough to have split phase power coming to my house. However I was unlucky in that I was still working back then and was not there when wires were pulled. If I had been there I would have insisted that neutral and ground wires be pulled in addition to the two hot wires. It is not against the Philippine electrical code to pull only two hot wires. And laying two wires is half as expensive for the contractor, so that is what they will do unless told otherwise.
On my next visit I will be looking into a project to pull additional wires, ground and neutral. More for safety considerations than anything else. I mean all my major appliances were bought in the Philippines. And I always check other electronics to make sure it has a 110/220 VAC adapter. Most electronics is dual voltage now days. It is major appliances that are not.
Currently I do use some step-down transformers rated in Kilowatts (KW) for things like the Kitchen Aid mixer that is 110 VAC only. Need a couple of KW for the motor startup, but after that it draws much less power.
Anyway your situation will be different from mine. The first thing to check is the power line coming from then pole. If it is two wire you have 220 VAC single phase. If it is three wire you have 220 VAC split phase.