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sandhu
Jul 16, 2007, 10:47 PM
Q. What is derating factor for cable laying when different size of cables are laid together?

tkrussell
Jul 17, 2007, 02:54 AM
Combining different size cables is not cause to derate. Derating is needed when the amount of current carrying conductors is greater than the ampacity of the standard 3 current carrying conductors will create more heat. Another reason to derate is if the wiring passes through an area with higher than normal ambient temperature.

danar
Jul 25, 2007, 11:09 PM
Hi, sir tkrussel
How about direct burial cables is deration applied if 4 cables(3C-300mmsq xlpe cu) are laid in one trench? What will be the suggested spacing and depth of the trench to attain minimum deration?
Thanks.

fathima123
Jan 9, 2010, 10:13 PM
Ambient temperature is 60deg centigrade.What is flexible cable size I have to use for 63A breaker inside the Low voltage switchgearpanel having IP-65protection.