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URGENT - XLPE Multicore Armoured 20 deg C temperature factor

Posted: Wed Nov 04, 2009 8:04 am
by Tonynat
Can anyone point me in the direction fo finding temperature tables for Multicore XLPE armoured cable at 20 deg C?

I need a figure better than 1.03, which is the last tabulated value in BS7671 for 25 deg C.

Thanks

Posted: Wed Nov 04, 2009 11:41 pm
by sparx
not sure what you are asking or hoping to achieve, presume you are looking at rating factors table 4B1, your cable is never going to run at lower than 25'C with any sort of load.
Are you trying to justify use of too small a cable size?
more info. plz

Posted: Sun Nov 08, 2009 8:31 pm
by Tonynat
Having looked at the ERA tables, I can get the 20 deg figure now. No problem.
However to answer the question, I am, as you surmise, trying to size a cable.
The area is fully air conditioned to be between 18 and 20 degrees.
Including the plantroom.

Another issue was using XLPE or PVC, if using XLPE the terminals on the equipment needed to be rated at 90 deg C, although I can calculate at 90 Deg C run at 70 deg C, which may have over come the problem.

Interestingly, the equipment supplier quoted the terminals to a BS that made them 70 deg C over ambient, therefore at 40 deg C the terminals would be rated at 110 deg C - seems unlikely!

Have resolved the problem now.
Thanks for your help.