Re: Aluminum cable trays
First refer to 250.96, 392.7(A), and 392.7(B), that should answer the question whether or not it is necessary. However the code will not tell you much as how to go about it. Your question is conflicting. There is the best way, and then there is easy.
Here is how I specify my jobs.
Each cable rack section shall be bonded with a bonding jumper sized per the largest OCPD. (I usually specify #6 AWG cu on steel racks. You can use aluminum just be sure to check largest OPCP). The bonding jumper shall be as short as possible and fitted with UL listed two-hole compression connectors on each end. The compression connector holes shall be 5/16? on 1-1/2? centers. The compression connector shall be installed with a compression tool that meets UL requirement of the connector. The cable rack shall be drilled to accept the compression connector and all paint and debris removed at thread and connection points, and contact surfaces. ?? hex bolt, flat and lock washers shall be used to terminate bonding jumper to cable rack. A light coat of anti-oxidant inhibitor shall be used on all contact surfaces of the cable rack, compression connector, and bare wire strands to prevent oxidation.
That gets the cable rack bonded. You will then need to bond it to a ground terminal somewhere. I bond it everywhere it passes a ground bus with 1/0 AWG using the same methods as bonding jumpers.
Since you are using aluminum cable rack you will need to use appropriate hardware and anti-oxidant. Anyway that is how I do it. How you choose to do it is your business. Good luck. Dereck
[ June 04, 2003, 07:52 PM: Message edited by: dereckbc ]
