Hi Tradingpaint!
When you mentioned 400 amp disconnects are you referring to cable disconnects? I say this because, that may be the problem...
You may be looking at a wire chart instead of looking for a welding cable chart... I'll get back to you later today so that I could steer you in the right direction... Of course, there are others here that will also be able to help so, talk to you later!!!
Respectfully,
SSBN727 Run Silent... Run Deep!!!