[Amps] 230v wiring question

[Tom W8JI]

>     I am not an electrician, but I wouldn't be concerned 
> about the
> voltage drop on a 35-foot run of 12-gauge wire.  12 gauge 
> certainly
> is OK for 240 VAC electric heaters, etc.  I'm sure it's 
> good for a
> lot more than 20 amps, and your TL-922 isn't going to draw 
> anywhere
> near 20 amps, anyhow.

Amplifiers and other devices with capacitor input power 
supplies have terrible power factors. The stiffer the power 
supply (the better the PS construction) the worse the power 
factor becomes.

This means wiring, so far as voltage drop or voltage 
regulation is concerned, has to be significantly heavier 
than the same average power with a purely resistive load.

It isn't a heating issue or an RMS voltage change, it is a 
voltage regulation issue caused by peak clipping since the 
rectifiers conduct much less than a full cycle. As a matter 
of fact voltage drop in power lines has to be measured with 
a peak detecting meter.

This is why it is often a good idea to oversize amplifier 
wiring, and poor power line regulation is why amps sometimes 
surprise us with a regulation improvement when moved to 240V 
when they aren't really near the wiring gauge limit on 120V.

73 Tom