In the US, there are two phases that is 120V each to neutral. If you connect it phase to phase, then you get 240V. In my country. It's illegal to use phase to neutral of 120V because we are promoting our local products which run at 240V only (to avoid buying stuff from US). Hence are only allowed to use phase to phase of 240V.
Now I just bought a 240V Ground Fault Circuit Interrupter. A normal line to neutral GFCI would have current flowing from line to neutral. But in my case, it's 2 phases without neutral. So can the GFCI still work?
How does the current flow in phase to phase connection versus phase to neutral? Are they the same?
Best Answer
GFCI's don't care.
GFCI has no relationship with ground. They don't care if the two wires are line-line or line-neutral. In fact your GFCI's labeling reflects that.
Also that is not 2-phase, it is single-phase with center ground.
You didn't mention you are in the Philippines. You don't have neutral, unless you are in the US-built territories that are still officially split-phase with a 3-wire feed from the transformer. If you are only getting 2 wires off the pole, the thing in the middle is only your ground rod, and it is definitely not made for returning current. If you try to hook a 120V load line-ground, in the Philippines, you will only electrify all your house's grounds.
Also, using a step-down autotransformer in the Philippines is a bad, bad idea. Both 120V outputs will be hot, and it will be very important that you get grounding right. In the Philippines you need an isolating transformer.