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#91852 - 02/09/05 12:20 PM 4160 volt conductor rateings  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 822
Michigan
Table 310.73 2001-5000 volts M.V.105.
500kcmil =530 amps for derateing 475 for terms(110.40). As i see it no derateing for a bank of pipes in open air. Thus 2000 amp requirement = 4 sets 530x4=2120
or 4 sets 475= 1900 amps.
240.101 states fuse can be 3 times conductors ampacity breaker or electronically actuated fuse up to 6 times.


So as I see it conductors must be rated for the ampacity of the true load. Over current protection can be higher then conductor rateings.
The highter amps rateing 105% for derateing only the 90% rateing for terms.
so if load is 1900 amps or below 500s can be used ,fused at 2000 amps.


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#91853 - 02/10/05 02:28 PM Re: 4160 volt conductor rateings  
Bob  Offline
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Joined: Feb 2002
Posts: 182
Mobile, AL, USA
Yoopersup
What is the load your are working with?


#91854 - 02/11/05 08:58 AM Re: 4160 volt conductor rateings  
Yoopersup  Offline
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Joined: Mar 2003
Posts: 822
Michigan
Last sentence says 1900 amps or below.



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