AnthonyL wrote:

So in the coffee bar this morning chat pondered on 3-phase and how to
know which of the 3 wires was which phase. I've done some googling
and would like the experts to confirm:

1. It doesn't matter which wire is which phase providing the sequence
of 1-2-3 2-3-1 or 3-1-2 is maintained when connecting, or any pair
swapped if that is what is required.

2. The voltage between any two phases is 440v and it doesn't matter
which two

and

3. The voltage between any phase and ground/neutral is 240v

Is that correct?

Are there any conditions when the phase needs to be known? If so how
is it detected?

Totally ignorant comment he

Surely there is no absolute phase (in power distribution at least), just
phase in relation to the other two phases. So no real life equipment
could know the difference as long as you can swap any two if it is
wrong.

Is it good practice in real life to keep the same colour wires
throughout the whole installation for each incoming phase?

--

Roger Hayter