bonding

[kjless]

ok this issue seems to be very controversial. article 250.97 says we do not need to bond metal raceways entering a panel unless they have concentric or eccentric knock outs. unless listed. we have PVC undergrounds coming through a concrete floor then changing to EMT entering EQP witch is fed from MDP 480 volts. the local inspector is saying i need to bond those EMT connectors. i said that i did not think that was correct. he said it was because its over 250 volts to ground. but after reading 250.92(b) except b1 it still has the same exceptions. so in my eyes he is wrong.

 

[fireryan]

It seems to me that 250.92 is for services and 250.96 is for other enclosures. But if im reading correctly you should be covered by 250.97 ex.3

 

[tryinghard]

...article 250.97 says we do not need to bond metal raceways entering a panel unless they have concentric or eccentric knock outs. unless listed. we have PVC undergrounds coming through a concrete floor then changing to EMT entering EQP witch is fed from MDP 480 volts. the local inspector is saying i need to bond those EMT connectors. i said that i did not think that was correct. he said it was because its over 250 volts to ground. but after reading 250.92(b) except b1 it still has the same exceptions. so in my eyes he is wrong.

250.97 Does refer to 250.92(B)(2)-(4) as a means to bond your circuit but don?t miss the whole part of 250.92(B), 250.97 only excludes (B)(1).

I think the inspector is right notice the last paragraph of 250.92(B), there?s no way around this unless you enclosure is listed to allow with concentric/eccentric knockouts.

I don?t believe the stub/riser lengths matter; it is because the stub/risers are conductive. You could install PVC all the way to get around the bonding.

 

[iwire]

ok this issue seems to be very controversial. article 250.97 says we do not need to bond metal raceways entering a panel unless they have concentric or eccentric knock outs. unless listed. we have PVC undergrounds coming through a concrete floor then changing to EMT entering EQP witch is fed from MDP 480 volts. the local inspector is saying i need to bond those EMT connectors. i said that i did not think that was correct. he said it was because its over 250 volts to ground. but after reading 250.92(b) except b1 it still has the same exceptions. so in my eyes he is wrong.

If you did not enter the panel through a concentric or eccentric KO you are not required to use a bonding bushing.