Rick,
The shorter the length of wire and the higher the load, the more critical the length becomes. I normally lay the conductors out and cut them all the same length before installing them. Finding space for the excess wire is sometimes a problem.
If you look at your installation and assume 4 sets of 600 kcmil with a calculated load of 1680 amps and multiple service disconnects and cable lengths of 20', 21', 22' and 23', we will find that the two shortest cables will be carryign more than there rated 75 degree ampacity. The 21' would be at 452, the 21' at 428, the 22' at 409 and the 23' at 391 amps. The rated ampacity of 600 kcmil is 420 amps.
Don(resqcapt19)
