Not sure on that, if you use phase to phase then you will never get over voltage due to loss of neutral so having a 240 volt phase to phase means you can use it, where at 400 volt there is no equipment that can use it. However question is what is the real phase to phase voltage?
Even in UK there are three systems used.
1) 230 volt transformer, used with outlying houses.
2) 460 volt transformer centre tapped used with outlying farms where more power is required.
3) 400 volt three phase star transformer secondary which give 230 volt phase to neutral.
In USA there is a further option where a delta secondary is used and one winding is centre tapped, I have read about it but never used it.
So when working in Algiers in Algeria 1981 I came across the 110 volt three phase supply, one electrician before me had decided to fit a 220 volt AC unit across the phases, however these were failing on a regular basis burning out the overloads built into motor which switch motor off if it stalls, simply 2 x 110 does not equal 220 volt as the phase are 120° apart not 180° so voltage was 190 volt.
So if the phase to phase voltage is 240 volt then the phase to neutral could be either 138 or 120 depending if three phase or split phase. I think the USA system is based on 120 volt so either 240 volt phase to phase or 208 volt if split phase.
So if the supply is designed to be used phase to phase then it would not be same as USA. On the Falklands I came across generators with 12 windings, these could be configured to give single or three phase (zig zag wired) and voltage 110, 230, or 400. Where the AVR was connected and set was also important. And I found imported equipment with voltages 110, 120, 220, 230, and 240 volt, when I think back before the switch mode power supplies it was common to see radios and like with these voltage options with tappings on transformer.
I remember as a boy going to Llwyngwril where they still had 110 volt DC supply, the problem was getting 110 volt DC equipment, so they were very pleased when the national grid arrived and they could use 240 volt AC stuff like everyone else. I will guess around 1958 when it changed.
So it is really down to what equipment is for sale on the Philippines, it would seem that 240 volt 60 Hz is the official supply, and like our 110 volt supply there is no neutral as such, the problem is all switches and MCB's all have to be twin pole just like out 110 volt supplies to building sites.
In many ways there system is safer than ours, with only 110 volt to earth, I did once in error try this on the Falklands however the problem was getting consumer units and other equipment with twin pole MCB's and fuses, there were plugs like these
where the pins were fuses, but can't get a British 3 pin plug with two fuses, so had to return to neutral and line system. With our 110 volt as used on building sites the cable cores should be brown, black, green/yellow and the plugs and sockets marked L1, L2 and Earth and since yellow cable not used with 230 volt no real reason why it should not have correct colours, however all yellow cable I have used is brown, blue, green/yellow and plugs marked L and N so we have to use what we can buy.
Same in Philippines what is for sale dictates how you use the power.
