Grounding Electrode Required or Not

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Ken9876

Senior Member
Location
Jersey Shore
Here is my situation, I have a utility trailer with a 7KW 120/240 permanently mounted generator installed, the trailer has a 4 pole transfer switch and provisions to be connected to another source. The connected load to this trailer exceeds 7KW, so when they are using this trailer it is going to be connected to a portable trailer mounted generator, via a 4 wire cord terminated at the generator with cam locks. After reading the code on vehicle mounted generators and portable generators I’m thinking that I will not need a grounding electrode connected while power is being supplied by the portable generator. The cam locks were added to the portable generator with short jumpers terminated at the supply lugs.
So my question is do I need to connect to a grounding electrode?
 

david

Senior Member
Location
Pennsylvania
250.34 would exempt the generator from a GEC.

Since when is a utility trailer required to have a GEC?

I think it needs clarified that the utility trailer is being supplied by a vehicle mounted generator.

I would not look at the 4 pole transfer switch on the utility trailer as cord and plug connected equipment.

I do not see an exclusion in 250.34 for the vehicle mounted gen. since it is supplying equipment that is not cord and plug supplied equipment

edit The OP ask if a grounding electrode is required he did not specify for which vehicle
 

david

Senior Member
Location
Pennsylvania
Here is my situation, I have a utility trailer with a 7KW 120/240 permanently mounted generator installed, the trailer has a 4 pole transfer switch and provisions to be connected to another source. The connected load to this trailer exceeds 7KW, so when they are using this trailer it is going to be connected to a portable trailer mounted generator, via a 4 wire cord terminated at the generator with cam locks. After reading the code on vehicle mounted generators and portable generators I’m thinking that I will not need a grounding electrode connected while power is being supplied by the portable generator. The cam locks were added to the portable generator with short jumpers terminated at the supply lugs.
So my question is do I need to connect to a grounding electrode?

the trailer has a 4 pole transfer switch and provisions to be connected to another source. ...................... I’m thinking that I will not need a grounding electrode connected while power is being supplied by the portable generator. -----------------------------------
So my question is do I need to connect to a grounding electrode?


If I understand correctly you have a separate structure (happens to be a utility trailer) being supplied by a normal source and backed up by a generator through a 4-pole transfer and your question is does this separate structure need a grounding electrode

Edit: my question would be is it now or will it be connected to the normal source.
Or is there just provisions for the utility trailer to be connected to the normal source
 

Ken9876

Senior Member
Location
Jersey Shore
If I understand correctly you have a separate structure (happens to be a utility trailer) being supplied by a normal source and backed up by a generator through a 4-pole transfer and your question is does this separate structure need a grounding electrode

Edit: my question would be is it now or will it be connected to the normal source.
Or is there just provisions for the utility trailer to be connected to the normal source

No, the utility trailer will be powered by a separate trailer mounted generator as the gen set in the utility trailer does not have enough capacity. I could plug the utility trailer into a premises wiring system as well, however this was setup to be used at remote locations with the trailer mounted gen set.
 
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david

Senior Member
Location
Pennsylvania
No, the utility trailer will be powered by a separate trailer mounted generator as the gen set in the utility trailer does not have enough capacity. I could plug the utility trailer into a premises wiring system as well, however this was setup to be used at remote locations with the trailer mounted gen set.

I think it needs clarified that the utility trailer is being supplied by a vehicle mounted generator.

I would not look at the 4 pole transfer switch on the utility trailer as cord and plug connected equipment.

I do not see an exclusion in 250.34 for the vehicle mounted gen. since it is supplying equipment that is not cord and plug supplied equipment

edit The OP ask if a grounding electrode is required he did not specify for which vehicle

Ok,
so what you are calling a separate trailer mounted generator is supplying loads not mounted on that vehicle, and is supplying loads that would not be classified as cord and plug equipment. it is supplying a substantial load on the first utility trailer that has its own generator.It does not sound like the generator on this first utility trailer is supplying any of the loads in this discussion.

Would you agree that the separate vehicle mounted generator system that is supplying the load would be required to have a grounding electrode
 

david

Senior Member
Location
Pennsylvania
The trailer will be in use for a few days

ARTICLE 590 Temporary Installations

590.2 All Wiring Installations.
(A) Other Articles. Except as specifically modified in this article, all other requirements of this Code for permanent wiring shall apply to temporary wiring installations

Ok,
so what you are calling a separate trailer mounted generator is supplying loads not mounted on that vehicle, and is supplying loads that would not be classified as cord and plug equipment. it is supplying a substantial load on the first utility trailer that has its own generator.It does not sound like the generator on this first utility trailer is supplying any of the loads in this discussion.

Would you agree that the separate vehicle mounted generator system that is supplying the load would be required to have a grounding electrode

After you get past the grounding electrode at the vehicle mounted generator (separate trailer)

250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).

I would say that a feeder supplied separate structure is required a grounding electrode

Edit both trailers could be placed close enough together i am not indicating you would need separate electrode the same electrodes could be used
 
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