medium voltage cable overcurrent protection
medium voltage cable overcurrent protection
(OP)
I am curious why NEC article 240-101 which states the long time delay overcurrent protection on cables >600v can be set at 6x the ampacity is at odds with the ampacity tables. What is the thought process between the two.






RE: medium voltage cable overcurrent protection
RE: medium voltage cable overcurrent protection
regards,
musa UKPN
RE: medium voltage cable overcurrent protection
RE: medium voltage cable overcurrent protection
RE: medium voltage cable overcurrent protection
RE: medium voltage cable overcurrent protection
If the cable circuit you are protecting is feeding a single customer; you may go for lower overload settings if you wish.
Can I ask are these settings to be adapted at utility breaker or breaker at or near the customer's site?
Also consider the period of the overload. If this is of short duration < 30 min and its occurance is rare/ occasional; the impact on cable life can be ignored. The cable ampacity at design stage should be decided keeping in mind the customer's load requirements plus any future growth. If we strict to these golden rules; the cables wouldn't be subject to overload any way and we could a higher overload settings can be used.
musa UKPN
RE: medium voltage cable overcurrent protection