Cable de-rating factors
Cable de-rating factors
(OP)
Dear Folks,
Please clarify the following:
How power Cable "ambient temperature de-rating factor" will depend on different protection systems?
In one of the cable catalogues it is given as follows:
for Example:
Ambient temp: 50 deg.C
Semi enclosed fuse to BS 3036 : 0.91 (Derating factor)
Fuse to BS 88 or BS 1361, or circuit breaker to BS 3871 part 1 : 0.82 (derating factor)
Advanced thanks...
Please clarify the following:
How power Cable "ambient temperature de-rating factor" will depend on different protection systems?
In one of the cable catalogues it is given as follows:
for Example:
Ambient temp: 50 deg.C
Semi enclosed fuse to BS 3036 : 0.91 (Derating factor)
Fuse to BS 88 or BS 1361, or circuit breaker to BS 3871 part 1 : 0.82 (derating factor)
Advanced thanks...






RE: Cable de-rating factors
For insulated cable, there are several limiting factor such as ambient temperature, number of cable and characteristic of the raceway, protective device speed during short circuit, insulation and conductor materials, etc.
Enclosed is a diagram SC illustrating some of the current derating effects: htt
RE: Cable de-rating factors
As of my knowledge, Protective device rating will depend on cable short-circuit capacity but not on ambient temp of the cable.
But one of the leading cable manufacturer given different de-rating factors for using different protective devices for the same ambient temp. (let us say at 50deg.C)