bonding at line side of service

[pugczup]

I am installing a 400 amp service at a farm. I have a 400 amp meter base and I installed a 200 amp main breaker panel on each side of the meter base. My question is, am I required to bond both sides of the nipple carrying the service conductors from the meter to the main breaker in each panel. I installed a grounding bushing on the panel side of the nipple going to each panel and bonded that to the neutral in the panel. I also looped my grounding electrode conductor
from one panel to the next and then to my grounding electrodes, running it external to the meter base through pvc sch. 80 conduit. The electrical inspector is requiring me to install grounding bushings on the meter base side of these nipples and bonding it to one of the neutral bars in one of the panels. This would require me to run a bare ground through one of the nipples, and a bare ground inside of the meter base. Any help on this would be appreciated.

 

[kbsparky]

Re: bonding at line side of service

...Any help on this would be appreciated.

Use PVC for your nipples. No grounding necessary.

 

[infinity]

Re: bonding at line side of service

My question is, am I required to bond both sides of the nipple carrying the service conductors from the meter to the main breaker in each panel.

The answer is no. You're required to bond only one side. This could also be accomplished with bonding locknuts or bonding wedges if no concentric or eccentric KO's are used. Bonding bushings are not your only choice. Take a look at 250.92(B)(4).

 

[jimwalker]

Re: bonding at line side of service

I would have went from grd rods to meter can and used plastic nipples between can and panels.What your about to do is create a second neutral.Here the poco wants to see grd rods go to meter first.

 

[jbwhite]

Re: bonding at line side of service

Originally posted by jimwalker:
What your about to do is create a second neutral.

I thought only a transformer with a center tap could create a neutral.

 

[infinity]

Re: bonding at line side of service

Originally posted by jimwalker:
I would have went from grd rods to meter can and used plastic nipples between can and panels.What your about to do is create a second neutral.Here the poco wants to see grd rods go to meter first.

Around here we're not permitted by the POCO to connect the ground rods at the meter enclosure. We always go to the service disconnect.

Regarding his use of metallic conduit, the original post said that he already installed it so I'm assuming that he's looking for a way to make it compliant without changing his conduit to PVC. This can easily be accomplished by installing bonding wedges on one side of the metallic nipples without removing conductors or conduits.

 

[mc5w]

Re: bonding at line side of service

However, if you connect the grounding electrode conductors to the meter socket rather than the service panels then you need separate neutral and equipment grounding wires going from the socket to the panels and separate neutral and grounding bars in the panels just like with a feeder.

The other thing to watch is that running steel conduit from a meter socket to a services switch with the grounding electrodes conductors going to the services switches tends to disable the lightning arrestors that are inside of electronic meters. Some electrical utilites have been requiring a dedicated grounding electrode and conductor for the meter socket to get around this problem.

Cleveland Electric Illuminating Company requires that a current transformer cabinet be grounded using separate neutral and equipment grounding conductors that are bonded to each other inside of the service switch - CEI does not allow 250.92(B)(1) and 250.142(A)(1) for grounding of CT cabinets and meter sockets. This seems to be a matter of preventing flow of neutral current in metal conduits and a few other bad things. Parma, Ohio requires the use of galvanized rigid conduit for the aboveground portions of new ( not replacement ) electrical services particularly between the meter socket and the service switches.

 

[iwire]

Re: bonding at line side of service

Originally posted by mc5w:
However, if you connect the grounding electrode conductors to the meter socket rather than the service panels then you need separate neutral and equipment grounding wires going from the socket to the panels and separate neutral and grounding bars in the panels just like with a feeder.

Not true at all under the NEC.