aerial cable span

[drbond24]

I have a customer asking about minimum support spacing for running cables along the outside wall of a building. They are running four 750 MCM cables. Earlier, I found an NEC article that said minimum support spacing was 15 feet, but now I can't find that same article again. The customer now wants to know what the support spacing would be if aerial cable were used. Help please !!!

 

[mdshunk]

Yeah, try 398.30 (A) (B) and (C).

Don't forget to account for sag when ordering wire.

Bigger than 250's in industrial establishments can be up to 30 feet if you want. I've seen them as close as 5 feet in mills to accomodate a cable buss type tap arrangement.

 

[drbond24]

Thanks, that was the answer to the first part. Does the NEC cover the span for aerial cable runs (conductors strapped together with messenger), or is that the NESC?

 

[Pierre C Belarge]

Go back one page from Art 398 to Art 396 Messenger Supported Wiring.