Are you sure about your 21,000 Watt assertion?
I agree the number looks high. I checked my math. The 30A connectors are rated UL1977 to 40A and CSA rated to 30A at 600V.
Using the average between the two ratings:
Power (W) = VxA = 600V x 35A = 21,000W (Simple Ohm's law equation which APP lists in their engineering reference sheet, links below).
"To achieve UL 1977 approval for a 600V rating, we test our connectors for dielectric withstanding voltage. The connector
is tested at 2 times the rated voltage of 600V plus 1000V or 2200VAC for 1 minute. "
http://www.andersonpower.com/product...onnectors.html
http://www.andersonpower.com/literature/datasheets.html