about chiller feeder
about chiller feeder
(OP)
hi, i was informed that hospital's chiller manufacturer wants a feeder size for feeding of about( its load is 100 KVA)) 120 mm2 (underground cable which has a capacity of 170 ampere,) İ calculate that a 120 mm2 cable has a capacity of 320 Amp and it is too much and i guess a cable of 50 mm2 is enough roughly, pls tell me why this chiller feeder is asked too compared to a simple calculation.is it about starting current? if so i know thay NEC wants minimum %125 size cable on the basis of the load value.but why this chiller feeder needs ABOUT 5/2 of the load ampacity?...






RE: about chiller feeder
More data please -- voltage, phase, length of feeder, is the chiller reciprocating or centrifugal, etc...
Thanks and good on ya,
Goober Dave
RE: about chiller feeder
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If it is broken, fix it. If it isn't broken, I'll soon fix that.
RE: about chiller feeder
RE: about chiller feeder
RE: about chiller feeder
How did you "calculate" 320A ampacity?
What does manufacturer of the cable say about the ampacity?
What type of cable? Cu or AL? 3-conductor with armor and PVC jacket? Singel conductors?
NEC or not you need to size 125% of the continuous current. Do you know your local codes?
RE: about chiller feeder
RE: about chiller feeder
RE: about chiller feeder
- There are more cables in proximity
- You also derate your cable when the temperature it is expected to be laid in is higher than its temperature rating.
- the kind of laying used (duct or tray; direct burial)
I don't know how it is with IEC but see NEC 310 for the recommended derating factor.RE: about chiller feeder