400V cable derating - strange configuration
400V cable derating - strange configuration
(OP)
Hi All
I am looking for any standard that has an ampacity derating rule that can be applied to the following case:
So practically it is 3 groups of 3 multicore cables, each group laid in trefoil
I am willing to pay for any standard (BS, NEC, IEC) if it has a case I can apply to this cable arrangement.
I am also willing to consider the cable arrangement equivalent to 12 multicore cables, with 6 layed directly on top of another 6, in cable ladder - if that helps
I am a little bit desperate :) Thanks for your help
Cheers Michael
I am looking for any standard that has an ampacity derating rule that can be applied to the following case:
A circuit is comprised of 3-off 3 core cables connected in parallel. The multicore cables making up the parallel group are touching, in trefoil there are 3 of these groups touching on cable ladder,
So practically it is 3 groups of 3 multicore cables, each group laid in trefoil
I am willing to pay for any standard (BS, NEC, IEC) if it has a case I can apply to this cable arrangement.
I am also willing to consider the cable arrangement equivalent to 12 multicore cables, with 6 layed directly on top of another 6, in cable ladder - if that helps
I am a little bit desperate :) Thanks for your help
Cheers Michael






RE: 400V cable derating - strange configuration
We normally use single phase cables in the U.S., so I don't have any ready answers that would help further with three phase cable arrangements with trefoil.
Good luck.
RE: 400V cable derating - strange configuration
ICEA-NEMA Standards Publication No. P-54-440, "Ampacities Cables in Open-Top Cable Trays"
Or the new one:
NEMA WC 51 AMPACITIES OF CABLES INSTALLED IN CABLE TRAYS ** SAME AS ICEA P-54-440 **
RE: 400V cable derating - strange configuration
http://www.openelectrical.org/wiki/index.php?title...
RE: 400V cable derating - strange configuration
(1) Vertical spacing between layers is at least 300mm and there is at least 20mm horizontal clearance between the layer and wall
That means the cables are touching horizontally but are not vertically.