On Sat, 15 Jan 2005 07:26:20 +0800, Old Nick
wrote:

On Fri, 14 Jan 2005 14:12:07 +0800, Old Nick
vaguely proposed a theory
......and in reply I say!:

remove ns from my header address to reply via email

hmm....unusually slow response.

HOWEVER. I realised (and meant to post) that it may well have nothing
to do with voltage drop, but simply the cable's ability to carry the
current without burning up the shop. Hence although the original cable
is short, to carry the 400A it has to be large.

I am going with 50mm^2. It is not that much more expensive and cannot
hurt.

Voltage drop is an issue with MIG, but you should be OK with 50 mm^2
and it certainly won't burn down the shop at 220 amps.