GEC for 2 Services (Inside one service)

[TrickleCharge]

There are 2 services. THe GEC comes in to one of them in to the ground buss bar (ufer ground). The second service is right next to the first and the EC ran the GEC for this from the service to the ground buss of the first service. Allowed? Does this go against 250.64(C)? I think ultimately the solution that is most commonly seen is an external ground bar that is used as a point of connection for all GEC to come in to but they did not do this. THanks

 

[petersonra]

are you sure they are both services?

 

[Smart $]

are you sure they are both services?

While I agree your question is noteworthy, I have to wonder whether it makes a difference. For example, it may be one service with service entrance conductor taps to power two grouped service disconnects.

In either case, it would be a violation of 250.64(C). For the latter example case, compliance with 250.64(D) is required in addition to 250.64(C).

 

[petersonra]

THe GEC comes in to one of them in to the ground buss bar (ufer ground).

I thought it had to go to the neutral bus.

 

[TrickleCharge]

While I agree your question is noteworthy, I have to wonder whether it makes a difference. For example, it may be one service with service entrance conductor taps to power two grouped service disconnects.

In either case, it would be a violation of 250.64(C). For the latter example case, compliance with 250.64(D) is required in addition to 250.64(C).

I know it seems like every now and then I get these questions asked that make me think if Im calling it right or not because Ive been so used to just seeing them a certain way that is code compliant. These are 2 separate services that have 2 service laterals running to the utility connection. When we see an external ground bus that is used for all electrodes to connect to in an electrical room, how does this differ than say a ground bus inside electrical service one. Basically you are using lugs to make the connections as you would on an external ground bus right and it is accessible by taking off the bottom panel of the service? Where would have you to do an exothermic weld to connect the second service or does just simply landing it in the ground bus of the first service work?

 

[Smart $]

I know it seems like every now and then I get these questions asked that make me think if Im calling it right or not because Ive been so used to just seeing them a certain way that is code compliant. These are 2 separate services that have 2 service laterals running to the utility connection. When we see an external ground bus that is used for all electrodes to connect to in an electrical room, how does this differ than say a ground bus inside electrical service one. Basically you are using lugs to make the connections as you would on an external ground bus right and it is accessible by taking off the bottom panel of the service? Where would have you to do an exothermic weld to connect the second service or does just simply landing it in the ground bus of the first service work?

If the utility connection is the same for both laterals, this is considered one service where conductors are 1/0 AWG and larger. See 230.2 general statement, second sentence, and 230.40 Exception No. 2. If this is not the case, and characteristics of the services do not warrant more than one service, the install has a 230.2 violation.

Electrically, it makes little difference as long as the connections are sound. However, that little difference encompasses technicalities making it safer for personnel, property, and equipment. For example, if there is a lightning surge on service #2, the current to earth must pass through service #1 disconnecting means. Another example is when service #1's disconnect is being replaced, service #2 will be without GEC connection during the process.