Discuss Rating factor within an enclosure? in the Electrical Forum area at ElectriciansForums.net
which hand!is this a rule of thumb
Existing or new. Either or .....Is this an existing enclosure mate or are you designing it?
A bit more info please.
Yes . . . Within an enclosure such as a bus bar chamber, switchboard of metal constructionDo you mean where a smaller cable can be fed from a higher rated supply, as long as it is mechanically protected?
yep I'm fine with that one, but thanks for feed back. (BTW ...ocpd = obsessive compulsive personality disorder? ;-) )It doesn't up rate the CCC of the cable at all.
I think you're referring to a fault free zone, which is limited to 3meters.
If I understand what your asking, an example. 25mm cable connected to a bus bar system backed with 800A fuses. So long as that 25mm is terminated into a suitable ocpd within 3 meters and is mechanically protected along it's route. It's all good.
Rob. Agreed with regards to the safety margins, and in a lot of cases well over the top.
Off at a tangent a little. . . but still on current carrying capacity. If one doubles up on two cables would this simply double the current carrying capacity ?
that was my understanding also. But lets keepit simple !!!!!!!If you're using normal cable calculations then yes effectively.
Delve a little deeper into it and then no, there will be a difference. Nothing to worry about at the level we work at.
However 2 x 70mm wires will take more than 1 x 140mm wire.
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