In article ,
Rumble writes:
Andy Burns wrote:
Slightly OT as this is not really DIY, and certainly doesn't involve me
me making any wiring changes (burning down a fire HQ might not be
appreciated)

I need to use a 3-phase supply, which is presented on a red commando
socket, and is protected via a type-D 32A MCB occupying 3-DIN ways of
the distribution board (SquareD KQ+) can I check my understanding that
this will supply 32A *per* phase?

Yes it will be 32A per phase. This means that you can apply a total load
of upto 230V x 32A x 3 = 22kW.

Note that if your commando socket only has 4 pins then you have no neutral!

Type D means that the magnetic trip will operate at between 10x and 20x
the nominal rating (i.e. instantaneous trip at 320 to 640A on any of the
three phases).

You need to watch the earth fault loop impedance carefully with a
Type D breaker. You may need an RCD to ensure compliance with the
required trip time on a short to earth if you have a long cable or
a greater than ideal earth fault loop impedance. Type D breakers
are normally used only for loads with a large initial surge (e.g.
some motors).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]