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updating an ungrounded circuit

Posted By: umerleyd

updating an ungrounded circuit - 04/07/02 05:52 PM

I've just recieved a quick accurate response to a question about a new meeting room circuit. I'll try for two. None of the branch circuits in the building are grounded and I want to ground my new circuits. I've found the main water pipe at it's entrance into the basement. The electric service into the building is located within a foot of this 1 1/2" copper pipe.The service disconnect is grounded to this pipe. I would like to run a #6 copper wire from this pipe above a dropped ceiling to a JB of my circuit about 20 feet away. I'd like to attach the new ground to my new circuit. Is this proper procedure. Thanks again
Posted By: resqcapt19

Re: updating an ungrounded circuit - 04/07/02 07:32 PM

If you are installing a new circuit, you must install an EGC with the circuit conductors. The permission to extend an EGC to the water pipe is only for the replacment of old two wire receptacles with new 3 wire receptacles.
Posted By: umerleyd

Re: updating an ungrounded circuit - 04/07/02 08:05 PM

I guess my next question is if I can install a new ground bar on the existing breaker panel. Can I run my #6 from the water pipe or a ground rod and can I then only run a ground wire from the breaker panel to the new circuit or would I have to install a new sub panel.
Posted By: resqcapt19

Re: updating an ungrounded circuit - 04/08/02 12:06 AM

The equipment grounding conductor must be connected to the grounded conductor at the service disconnect via the main bonding jumper. You must have a fault clearing path back to the grounded conductor. Just a connection to the water pipe or ground rod is not code compliant and would present a serious safety hazard.
Posted By: tdhorne

Re: updating an ungrounded circuit - 04/13/02 04:22 PM

Why do you need a new ground bar? Is there no ground bar now? The neutral buss in service equipment is also the ground buss. In panels that are not serving as service equipment the grounded current carrying conductors (neutrals) and the Equipment Grounding Conductors, or EGCs, must be kept separate and insulated from each other to avoid the current in the grounded conductor from taking stray paths that can cause a shock hazard or arcing. I take it from your previous postings that the panel is not the service equipment and that you have a separate disconnect feeding it. If I'M right read on if not supply the correct layout.

If you are going to run just one new circuit from a panel, that is not service equipment, that has only served raceway or metal jacket grounding paths in the past then you can just use a metal cable connector and a half inch bonding bushing to connect the Equipment Grounding Conductor to the grounded metal Cabinet of the panel. If you will be running multiple circuits with separate EGCs from that panel you should install a ground bar.
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