Current on Ground

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Ive run into a situation where there is a 3 phase with ground supplying another building, its a feeder not a service. Im picking up about 1 amp of current on the ground. any suggestions on what could be causing this?? its got mostly sensitive electronic equipment in it, and yes there is also a transformer for 120/208 loads. This just seems dangerous in this scenerio.
 
Maybe a problem, maybe not.

Anything in Section 250.6 that may help out? All the rules of 250.32 being followed?

Give us the grounding and bonding arrangement at both buildings...
 
bphgravity said:
Maybe a problem, maybe not.

Anything in Section 250.6 that may help out? All the rules of 250.32 being followed?

Give us the grounding and bonding arrangement at both buildings...
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Ive read 250.6 and i belive that 250.32 is being followed. The ONLY major issue i see and im told that is ok, is that this trailer/building was originally to have a 5 wire, 3 hots 1 neutral 1 ground. But they made it a 4 wire, 3 hots 1 ground. It was said that the neutral was not needed. I did question that, however it does have a delta transformer inside.

Also there is suppose to be 'isolated' grounds in this /building, and they do bond with the neutral at the transformer. i would assume thats right cause its a seperately derived system.

But this 1 amp of current is bugging me. and they claim there is rf noise as well in this building. any suggestions.
 
iwire said:
Underground feeder?

Is it likely full of water?

Is the run long?
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How would this have an effect on the ground ?
 
A long run can (I am not sure of the correct word here) induce(?) current on the other conductors.

This is one of the reasons to limit the length of GFCI protected circuits.

A flooded conduit can cause current flow from ungrounded to grounded conductors.
 
iwire said:
A long run can (I am not sure of the correct word here) induce(?) current on the other conductors.

This is one of the reasons to limit the length of GFCI protected circuits.

A flooded conduit can cause current flow from ungrounded to grounded conductors.
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I could see this happening in a run with an under ground splice box in it also.
Maybe a small puncture in the insulation ?
 
acrwc10 said:
I could see this happening in a run with an under ground splice box in it also.
Maybe a small puncture in the insulation ?
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I think so too, but in either case if that is what is happening it will not be long before it gives out.

It also could be a lot of things, I was mostly just throwing out some ideas. Honestly an 1 to 2 amps on the EGC with 40 on each phase does not seem that worrisome to me but I could be wrong considering it is likely a hospital building.
 
iwire said:
I think so too, but in either case if that is what is happening it will not be long before it gives out.

It also could be a lot of things, I was mostly just throwing out some ideas. Honestly an 1 to 2 amps on the EGC with 40 on each phase does not seem that worrisome to me but I could be wrong considering it is likely a hospital building.
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Who said it was a hospital building?? and no this is not an underground feeder, and the run is about 30 ft. its above ground in rigid conduit.
 
The second building is required to have a grounding electrode, the feeder EGC is required to be connected to this electrode, the service grounded conductor is bonded to grounding electrodes at at least two, if not more locations, the earth is a parallel path for the grounded conductor current. One amp may be normal.
 
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