One meter, two services-separate buildings

[jdelectricsvc]

We have a customer with one meter socket suppling two 200 amp services. These services are in separate buildings. Buildings are approximately 30ft away from each other. Would it hurt to install a second ground rod in this application? It's just kind of nerving when you find the ground rod on top of the ground instead of driven into the ground.

 

[iwire]

The NEC requires a grounding electrode system at each building.

If the second building has a metal water supply you have to hook up to that as well.

 

[jdelectricsvc]

Thanks

Thanks

I appreciate the help, since we had a debate with the town municiple worker complaining about having to mark the service laterals and other utilities "just for driving a ground rod that wasn't need because it was all done at the meter, everything was grounded properly.....you're just wasting peoples' time and money."

 

[tom baker]

everything was grounded properly.....you're just wasting peoples' time and money."

Bonded maybe, grounded no. The grounding electrodes at the two buildings are for protection from lighting striking those buildings.

 

[ryan_618]

We have a customer with one meter socket suppling two 200 amp services.

It sounds like you have one service, with two feeder circuits.

 

[flash hazard]

It sounds like you have one service, with two feeder circuits.

i agree this sounds like one service with two feeders. 250.32 (A) would apply. im getting ready to take my ma. E-2, and in the ma. ammendments i remember reading an electrode was not required at a seperate building or structure. i dont have the ammendments with me can anyone confirm this or are there any other states with ammendments like this.

 

[Dennis Alwon]

It sounds like you have one service, with two feeder circuits.

Or an illegal 400 amp service.

 

[ryan_618]

Or an illegal 400 amp service.

You could have a service with two sets of service entrance conductors, in accordance with 230.40 exception No. 1.

 

[LarryFine]

Wouldn't each building need a complete GEC system connected to the grounded conductor at its main disco, as if it were the only building?

 

[iwire]

Wouldn't each building need a complete GEC system connected to the grounded conductor at its main disco, as if it were the only building?

I think I heard that in post 2. :grin:

Depending on the configuration it will have to be connected to either the grounded or the grounding conductor.

 

[iwire]

You could have a service with two sets of service entrance conductors, in accordance with 230.40 exception No. 1.

It could also be two sets of service conductors one each per building 230.40 Ex. 3.

 

[haskindm]

Whether this is on service or two, the fact that it is two buildings would require each building or "structure" to have its own Grounding Electrode System. The only exception I can think of for not having a grounding electrode at the seperate building would be if the building only contained one circuit per 250.32(A) Exception.

 

[Dennis Alwon]

You could have a service with two sets of service entrance conductors, in accordance with 230.40 exception No. 1.

The OP said they were separate buildings with one meter. If it is a 400 amp service then the discos need to be group. If that is the case then it is a feeder to one of the buildings.

If it is a 400 amp service with 2 services (as the op calls it) in separate buildings then that's illegal.

I didn't know exactly what he has.

 

[iwire]

If it is a 400 amp service then the discos need to be group. If that is the case then it is a feeder to one of the buildings.

If it is a 400 amp service with 2 services (as the op calls it) in separate buildings then that's illegal.

Dennis 230.40 Ex. 3 could also cover it.

But for us it's all just guessing, as we have not seen it.

 

[iwire]

If it is a 400 amp service then the discos need to be group.

By the way, just for fun.....How does one determine the size of an existing service?

 

[Dennis Alwon]

By the way, just for fun.....How does one determine the size of an existing service?

I guess I would look at the wire sizes that feed the service disco which should correspond to the Main breaker totals. But this is a trick question so I am assuming meter first and main discos after that.

 

[iwire]

But this is a trick question

No your on to it , I was just asking as you posted about a '400 amp' service and we have no idea what size this service is at all.

Because of 240.4(B) or 230.90(A) Exception 3 there are few instances where we can really determine a service size without looking at the conductors.

I could have two - 200 amp service disconnects supplied with 6 AL dependent on the calculated load.

 

[ceknight]

By the way, just for fun.....How does one determine the size of an existing service?

I do it by looking at the service laterals. From that I've been able to conclude that every house in central NY has a 30A service.

 

[iwire]

I've been able to conclude that every house in central NY has a 30A service.

:grin:


Yeah around here overhead services appear to be about a 60 but someone comes along and puts in a 400 amp breaker.

 

[Bea]

If it is a 400 amp service then the discos need to be group.

the service disconnects that supplied two different buildings due not have to be grouped unless one passes thru one bilding to get to the other