Metal conduit as ground and grounding water services

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ERB

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I had two issues to get clarified.
Multi unit commercial office building built in 1980. Neutral and earth ground bonded in main switchgear. Meters are fed from meter trough and each meter has a disconnect on the load side.
Issue 1. Any problems using conduit and meter can as ground between main switch and unit disconnect. No ground wire was run but continuous metal used and shows continuity on multi meter. Ground wire for service bonded in the disconnect enclosure and runs in PVC conduit to sub-panel.

Issue 2- Incoming main service is bonded to house water supply. At the opposite end of building are water meters that run to the individual units using copper piping. Any requirement on bonding water pipe from each meter.
 
Re: Metal conduit as ground and grounding water services

1. Yes, metallic enclosures and raceways can be used as equipment bonding and grounding on the load side of the service disconnect.

2. When you say the main service is bonded to the water supply, do you mean the metal unground water pipe is being used as a GEC? Have the requirements of 250.104(A)(2) been met?
 
Re: Metal conduit as ground and grounding water services

You may want to check with the serving electric utility. We require a conductor that is sized in accordance with 250.66 to be pulled in to ground the meter equipment that is in the feeder. That applies regardless of the raceway used, metallic or not. We are setting our cash registers in a feeder so we have to be compliant with the NEC; however, since we own the cash registers, we get to set some of the rules. :D
 
Re: Metal conduit as ground and grounding water services

Thanks for the response Bryan and Charlie.

Bryan, there is a driven ground at the service entrance and also a jumper over to the water pipe in the meter room. The water meters and services for the units are at the opposite end and run up to the individual tenants. They are not bonded from where we can see. Issue was someone getting shocked during thunderstorm touching both water and grounded electrical equipment.

Ed
 
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