Can any electricians out there tell me which of the following electrical supply systems are in use in Thailand please...

380 V 3Ø 50 Hz (5 wires - 3Ø + N + E)

230 V 1Ø 50 Hz (3 wires - 1Ø + N + E)

220 V 2Ø 50 Hz (3 wires - 2Ø + E)

110 V 3Ø 50 Hz (4 wires - 3Ø + E)

I know the voltage here is supposed to be 220/380, but I have often seen the voltage climbing above 400v thanks in advance...

380 V 3Ø 50 Hz (5 wires - 3Ø + N + E)

230 V 1Ø 50 Hz (3 wires - 1Ø + N + E)

Normally E is not counted as a 'wire' as it's not a current carrying conductor, so we have:

220 V 1Ø 50 Hz 2 wires - (1Ø + N) and

380 V 3Ø 50 Hz 4 wires - (3Ø + N)

i.e. we have a Y system with 220V phase-neutral and 380V phase-phase (roughly)

Nominally the supply is +-10% so we could see 198-242 and 342-418,

400V phase-phase (+5%) is just fine

NOTE There are a few villages that are 3-phase 3-wire 220V phase-phase but they do seem to be the exception and in remote areas.

Hi Crossy,

Thank you for taking the time to answer my question, much appreciated...