3 phase 240 volt motor wiring?

Question

My 3 phase motor has 3 wires to 3 live terminals (a b and c)and 3 neutral wires all to 1 terminal. how do i wire this for 240 use from an invertor

Answer 1

For a wye-connected machine:
The phase voltage (measured between a-b, b-c, or a-c) is (SQRT(3))* the line voltage (a-n, b-n, or c-n). In this case, connect your invertor across a-n, b-n, c-n (this may mean breaking the "common" neutral connection).

For a delta-connected machine:
The phase voltage equals the line voltage. In this case, connect your invertor across a-b, b-c, and a-c.

Which polarity you choose for the three connections will determine rotation - make sure your resultant rotation matches that on the machine nameplate, or you'll likely burn it up due to insufficient cooling...

Answer 2

Do you need an invertor? All you need is a capacitor across two of the terminals, and the supply acrossthe other terminal and one of the capacitor terminals. speaking from memory I think it was about 40 MFDs for 3/4 HP I think you ignore the 1 terminal To try and clarify -eg capacitor on A & B, and mains on B & C

Answer 3

Check the name plate. It sounds like you have a three wire single phase, 240 volt motor. If this is the case; you don't need a neutral as the center phase (b) would be neutral from a delta inverter.

Answer 4

You can't unless it's a 3-phase invertor in which case the connections will be obvious !