Derating Cables

[tboner]

When layering power cables on top of each other how should they be derated? For example, I want to put 12 cables in a cable tray: 3 rows of 4 with a barrier separating each row. I've found in the code (CEC - canadian) the derating factor for layering up to 2 layers, but nothing for beyond that. Any advice?

Thanks

 

[RRaghunath]

Just a suggestion,
Visit the website of any cable vendor.
If the requirement is not a common one, you can always pose a question and generally vendors do respond quickly.

 

[jraef]

Beyond derating, you have to think of consequences of stacking.

http://eng-tips.com/viewthread.cfm?qid=93479

 

[7anoter4]

Hi tboner
In my humble opinion as a conservative solution you me use
STOLPE THEORY (ICEA P-44-440)
For 12 power cables in the same tray. LAYED ON OPEN TRAY WITH NO DISTANCE BETWEEN ONE CABLE TO ANOTHER.
There are other theory for raised cover tray and another for closed covered cable tray.
Also VDE-298 TEIL 2/11.79 may be used for stacked trays with solid bottom or ventilated.
If the tray is exposed to sun another derating should be necessary.