4/0 Cable Support

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hoyerr

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I need a code interpretation. I have a questionable installation. I have a fiberglass enclosure that contains a bus strip with 4 4/0 weld wire cables attached. These are connected vertically. They exit the box thru a bushing, also vertically. There is a web type cable support attached approximatly 2 feet away. My question is Should the bushing be replaced with a strain relief fitting where it exits the enclosure?" I am looking at Art 312.5(C). I am being told by my electrician that the use of the remote web strain relief is sufficient. I think this is entirely 2 different issues. One is the exit thru the enclosure and the other is the required support for a vertical cable.
 
hoyerr said:
I need a code interpretation. I have a questionable installation. I have a fiberglass enclosure that contains a bus strip with 4 4/0 weld wire cables attached. These are connected vertically. They exit the box thru a bushing, also vertically. There is a web type cable support attached approximatly 2 feet away. My question is Should the bushing be replaced with a strain relief fitting where it exits the enclosure?" I am looking at Art 312.5(C). I am being told by my electrician that the use of the remote web strain relief is sufficient. I think this is entirely 2 different issues. One is the exit thru the enclosure and the other is the required support for a vertical cable.
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If you're asking whether or not a connector is required for the cables leaving the enclosure, I've never seen a connector capable of securing 4 individual conductors. I could see four separate connectors, one for each cable and then combined in the Kellums grip strain relief you describe. I would say the bushing with all four conductors exiting the enclosure together would not be the best choice in your situation.
 
I think the electrician is correct especially if you have a 90 degree fitting close below the enclosure then the conductor is supporting itself,,,, if not OZ Gedney sells wedge type support gromets of different configurations by OD and conductor sizes or you can order special arrangements.

dick
 
Without specific engineering input, I think it would be a judgement call.
Engineering data on the stress to the terminal, tinsel strength of the bolt, etc would all play a part.
Two feet of unsupported welding cable would not, IMO, be much of a strain.
 
iwire said:
Can I ask what the application is?

Not many times you can hardwire cables.
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I have 4 positive dc 4/0 cables connected to a common buss bar, exiting an enclosure out the bottom thru only for individual bushings. Esentially the cable is being supported by the buss bar untill it get to where the chiness finger trap cable support. The cables are connected from a rectifier to a submarine batterystring for formation charging. it runs at approximately 500 amps. The negative end is identical to the positive.
 
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