Load Bank connections

[caporter]

We have a generator that needs to be load bank tested. The output is 480V 3P 1000A. The test will be limited to 800A and we are installing a separate 1000A circuit breaker in an I-line panel to go to the load bank.

The methods I have seen so far for hooking up a rented load bank is to connect 4/0 welding cable into a circuit breaker with the panel exposed for the duration of the test. It works but violates a number of safety regulations. I want to use a panel of Cam-lok lugs (E1017 series) and have the contractor plug his 2 sets of 4/0 cables. According to to what I find in the NEC I need 700MCM cables for use in a raceway/conduit. My problem is I don't have room left in the panel for 700MCM cables. Is there a legal justification for using 4/0 cable for a short run, <6 feet, to the cam-lok lugs or perhaps a better method?

 

[dpc]

If the breaker is 1000 A, you need (at least)1000 A ampacity in the conductors, regardless of length.

 

[rbulsara]

700MCM is very large diameter cable, diffcult to handle and terminate. The breaker may not even accept 700MCM cables.

You may want to use multiple 4/0 "welding" cables. Check the ampacity of those cables in free air.

As for safety, you need to take necessary precautions and limit access to the test area during the test. Keep safe distance from energized components. Are you a contractor or desing engineer?

 

[waross]

Under the Canadian Code welding cable must be rated at 60 degrees. That puts 4/0 at 300 Amps in free air and 195 Amps in the panel. Probably why the panels are left open.
Try 4 x 250 MCM RW75 per phase.

Bill
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