Electrical / Insrumentation trays separation distance

[MARCOPEREZR]

Hello everybody.

I looked over at NEC and didn't find an answer.

Please point me where to find this information, minimun separation distance between electrical (power, lighting, control) cables and instrumentation (F&G, service, J1, J2, J3, ESD, SIS, Telecom, etc) cables in above ground instalations (trays).

Thanks in advance.

Best Regards.

MARCO

 

[itsmoked]

That's because NEC doesn't care if any of your circuits work or not! They just want to prevent fires and to a much lesser extent electrocution.

Because of the various susceptibilities and noise sources that abound you won't find a Standard. You may find some corporate or industry guidelines or rules.

Search in here for "cables separation control".

Keith Cress
kcress -

http://www.flaminsystems.com

 

[dpc]

The classifications you list don't mean much in NEC land.

Anything over 1000V must be separated. Below that, you're on your own - use company standards or best practices.

The NEC does require that all cables in a common tray, conduit etc must be insulated up to the highest voltage in use. So if you run 480 V circuits in the tray, everything else must be insulated to that level.

But itsmoked is very correct - the NEC is mainly a fire prevention standard, not an installation specification.

"The more the universe seems comprehensible, the more it also seems pointless." -- Steven Weinberg

 

[roydm]

I have often seen a metal barrier in a tray, this allows you to run HV and LV cables in the same tray with zero spacing.
Roy

 

[MARCOPEREZR]

Thanks for the replies.

The idea is not to run E&I cables in the same tray with a barrier but to use separate trays for each cable types but using the same support (same threaded rod in a hanging arrangement) and I don't know the separation distance between trays and since NEC doesn't have an answer I guess I'll just have to use 300 or 350mm.

Regards

 

[roydm]

MARCOPEREZR,
300 - 350 sounds OK, the trays need enough spacing so you can get your hands in to lay the cables

Roy

 

[Skogsgurra]

300 mm is what is used in most European paper mills and steel works. So it is probably fine.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[MARCOPEREZR]

Yes, 300mm sounds OK, the problem is that the client is requesting a document or specification stating that 300 is enough I can't find such information, I will continue looking.

Regards.