[Amps] 230v wiring question

[Tom W8JI]

> You will need 12/3 (which is 3 #12 wires & a separate 
> ground) to run a 220V circuit.
> Black and Red for the Hot wires. White for the Neutral and 
> the bare (or Green) for the Ground.

Three wires, two insulated and one bare ground, is fine as 
long as there is no current return on the neutral. Most 
correctoly designed amplifiers are built to float the 240 
system and not use a neutral return.

Four wires are only required if the PA has 120V circuits. In 
that case the 120V returns CANNOT be connected to the 
chassis, they have to float and be connected only to the 
neutral return. That means three insulated wires plus a 
ground.

>
> The Breaker will determine the gauge. If you install a 20 
> Amp breaker, you may run 12 Gauge. A 30 Amp Breaker 
> necessitates 10 Gauge wire.  Regardless of which gauge you 
> run, you can then terminate in a 15 Amp or a 20 Amp outlet 
> in the shack.

Not exactly. I have 000 copper for about 150 feet coming 
into my shacks and they are fed from  70 amp breakers. You 
can oversize the wire for the breaker, and that's what I do 
because (as Hams seem to constantly forget) capacitor input 
supplies have terrible power factor and a well-built supply 
does much better when a long run of wire is oversized.

Also, you should NOT use a 15 or 20 amp outlet on a larger 
breaker. Do NOT use a 30 amp breaker to power a 20 amp rated 
outlet. The weakest link sizes the breaker.

73, Tom