service entrance conductors bonding

[fireryan]

Here is the scenario. I have a 480v 1200 amp service. Service conductors come from pad mount transformer and go to a ct cabinet. From the ct cabinet the service entrance conductors go into a 3'' ridgid pipe to the switch gear. Had an inspection today and forgot to install grounding bushings on the pipe and instead used just a pvc bushing and it passed. I was always under the impression that you had to install grounding bushings on raceways for service entrance conductors. I looked at 250.80 and 250.92 and still believe i am correct. Am i missing something because of the ridgid pipe or did the inspector just miss something?

 

[electroman#1]

electroman#1

electroman#1

Its totally legel the way you did it when you have a good rigid nipple. They want you to use one of those with chines money off set pot metal nipples etc. I hope that helped

 

[hurk27]

Here is the scenario. I have a 480v 1200 amp service. Service conductors come from pad mount transformer and go to a ct cabinet. From the ct cabinet the service entrance conductors go into a 3'' ridgid pipe to the switch gear. Had an inspection today and forgot to install grounding bushings on the pipe and instead used just a pvc bushing and it passed. I was always under the impression that you had to install grounding bushings on raceways for service entrance conductors. I looked at 250.80 and 250.92 and still believe i am correct. Am i missing something because of the ridgid pipe or did the inspector just miss something?

Well maybe he assumed that it was bonded on the other end?? only needs bonding on one end.

My question is how do you get 1200 amps of service conductors in one 3" conduit? am I missing somthing?

 

[fireryan]

no poco doesnt allow gec's in there equipment. There a 4- 3'' pipes. Parallel 350's

 

[fireryan]

So i guess my question is does the ridgid pipe constitute a bond without the bushing?

 

[hurk27]

no poco doesn't allow gec's in there equipment. There a 4- 3'' pipes. Parallel 350's

A'hhhh ok that sounds better.

Well I guess we must remember inspectors are human and who knows how much is on their mind at the time of inspection.

Well it still needs to be done right, they do make after the fact split bonding washers that will slip over the conductors and pipe in place.

 

[fireryan]

A'hhhh ok that sounds better.

Well I guess we must remember inspectors are human and who knows how much is on their mind at the time of inspection.

Well it still needs to be done right, they do make after the fact split bonding washers that will slip over the conductors and pipe in place.

I agree. I just got me curious that if the whole time i didnt need to install the grounding bushings. Im gonna change them out if needed as the service isnt hot yet. Im reading in 250 and see 250.92b2. I think there is my answer. If im not using a hub it is required

 

[fireryan]

and then on second glance if you look at 250.92b1 it says "if equipment is bonded to grounded conductor". is a approved bonding method. Since the ct cabinet is bonded to the grounded conductor no grounding bushings are needed. I guess the inspector was right. I learn something everyday

 

[don_resqcapt19]

and then on second glance if you look at 250.92b1 it says "if equipment is bonded to grounded conductor". is a approved bonding method. Since the ct cabinet is bonded to the grounded conductor no grounding bushings are needed. I guess the inspector was right. I learn something everyday

250.92(B)(1) applies to "equipment" and not to the raceway. The CT can would be bonded to the grounded conductor, but at least one end of the raceway between the CT cabinet and the service disconnect requires some type of bonding other than standard locknuts. (I say at least one end because that is all the code requires, but our utility requires bonding at both ends of a raceway run between a meter or CT can and the service disconnect)

 

[kwired]

Pipe bonding clamps and jumper to neutral or grounding bus should work too.