PoCo Requesting Remove and Replace Rigid Steel With PVC for GEC Conduit From Meter

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jeremyp

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Just installed a service on the side of a new gas station. Power company came today and installed the meter and hooked up the transformer. The grounding electrode conductor is ran thru RMC at the meter base attached to strut on the side of the exterior metal cladding. The lineman that installed the meter is requesting that I replace the RMC with PVC because in the event of a fault, someone may get shocked standing next to the meter. Any other time I would just replace the thing and move on, but the conduit is encased in concrete.

Sometimes stuff is done the wrong way for so long that it seems like the right way, so am I messing up putting the GEC in RMC?
 
jeremyp said:
Just installed a service on the side of a new gas station. Power company came today and installed the meter and hooked up the transformer. The grounding electrode conductor is ran thru RMC at the meter base attached to strut on the side of the exterior metal cladding. The lineman that installed the meter is requesting that I replace the RMC with PVC because in the event of a fault, someone may get shocked standing next to the meter. Any other time I would just replace the thing and move on, but the conduit is encased in concrete.

Sometimes stuff is done the wrong way for so long that it seems like the right way, so am I messing up putting the GEC in RMC?
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The NEC requires that if a GEC is run in ferrous metal conduit you must bond the GEC to the conduit at each end.
Other than that the NEC does not make any pronouncements about shocks to meter readers. :happysad: And I do not see it as a credible hazard during a major fault or lightning strike anyway.
Worst case I suppose you could switch to PVC just below the surface of the concrete or you could insulate the exposed RMC.
 
GoldDigger said:
The NEC requires that if a GEC is run in ferrous metal conduit you must bond the GEC to the conduit at each end.
Other than that the NEC does not make any pronouncements about shocks to meter readers. :happysad: And I do not see it as a credible hazard during a major fault or lightning strike anyway.
Worst case I suppose you could switch to PVC just below the surface of the concrete or you could insulate the exposed RMC.
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The concern that I got second hand from the field engineer is that in the event of a fault or strike any current going thru the GEC would energize the entire building because the RMC is attached to strut which is attached to the building. Never mind the meter base itself is metal and bonded to the GEC and attached to the building. Or that the copper piping is bonded and attached, or the gas line is bonded and attached, or that the earth itself is probably bonded and attached.
 
jeremyp said:
The concern that I got second hand from the field engineer is that in the event of a fault or strike any current going thru the GEC would energize the entire building because the RMC is attached to strut which is attached to the building. Never mind the meter base itself is metal and bonded to the GEC and attached to the building. Or that the copper piping is bonded and attached, or the gas line is bonded and attached, or that the earth itself is probably bonded and attached.
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The GEC itself is directly or indirectly bonded to the building steel. The RMC is not going to change anything, AFAICS.
 
jeremyp said:
The concern that I got second hand from the field engineer is that in the event of a fault or strike any current going thru the GEC would energize the entire building because the RMC is attached to strut which is attached to the building. Never mind the meter base itself is metal and bonded to the GEC and attached to the building. Or that the copper piping is bonded and attached, or the gas line is bonded and attached, or that the earth itself is probably bonded and attached.
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Isn't the electrical equipment (which is connected to the GEC) attached to the metal building with metal fasteners? Sounds like a weak argument.
 
jeremyp said:
The concern that I got second hand from the field engineer is that in the event of a fault or strike any current going thru the GEC would energize the entire building because the RMC is attached to strut which is attached to the building. Never mind the meter base itself is metal and bonded to the GEC and attached to the building. Or that the copper piping is bonded and attached, or the gas line is bonded and attached, or that the earth itself is probably bonded and attached.
Click to expand...
They know something isn't right about it but are failing to tell you what that is.

Current flowing on on the GEC turns the whole thing into a single turn core and coil, the high current, high frequency of a lightning strike is going to yield the worst possible results and leave it with the highest impedance at a time when you want it as low as possible.

Normal operating currents are not all that likely to raise any voltage potential enough to be a problem for anyone standing in the vicinity or even working on the equipment.
 
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