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Joined: Mar 2005
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The equipment grounding conductor is the grounding wire in the cord connecting the pump. it is also in the circuit that supplies the receptacle the pump is plugged into.
Bonding the non-current carrying pump housing to the copper water piping is bonding only, and keeps both at the same potential.
Under a fault to ground condition the copper water pipe would parallel the EGC but, the water pipe is not intended to replace the function of the EGC.
Alan--
Alan--
If it was easy, anyone could do it.
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Joined: Jan 2004
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Very well said Mr. Nadon.
George Little
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Joined: Feb 2001
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250.104(A)(1)--Bonding of metal water piping is not allowed anywhere other than the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor, or the grounding electrode.
You may be calling it bonding, but when you bond the EGC to a metal water pipe that is not metallically isolated from the rest of the system, the water pipe is a parallel EGC and that is not allowed.
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Joined: Jul 2004
Posts: 9,928 Likes: 34
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Why do you think you can't parallel an EGC? Ever worked in health care?
Greg Fretwell
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Joined: Jan 2005
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The way the code is written, you almost have to end up with multiple 'parallel' ground paths.
One example that comes to mind is MC cable; the outer jacket is required to be bonded, plus there is the insulated ground wire.
I believe Steve got confused - as all of us have had happen - between the "grounded" conductor and the "grounding" conductor. The first is the 'neutral,' and the second is the 'ground.'
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Joined: Jul 2004
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I have seen inspectors who should know better saying the 680.26 bonding grid should be isolated from the EGC system. I am not sure how you would do that if you have a grounded pump, a heater, power pool cover, or an underwater light. There are certainly other places where these could get bonded toghther like a metal box on the screen cage.
They just misunderstand the FPN that says it is not required to extend the 8ga solid to the panel.
Greg Fretwell
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Sure you can bond a grid to the EGC, that grid is not the water system for the house. Sure you have to bond metallically isolated sections of metal that may become energized. But when you have a complete metal water piping system, bonding a piece of equipment to it at any point other than as allowed in 250.104, I contend it is wrong and also not a good idea. You risk someone getting shocked at any point on the water system if the motor shorts to the casing if it is bonded to the water piping system. Imagine bonding a gutter at the top section, to say a recept installed in the eave, then bonding it again to a recept near grade. If something shorts out on the eave recept, the gutter becomes a ground path and if someone is touching it could get shocked. Same concept for the water piping.
I don't know what you guys see normally, but all I have ever seen is copper or galvanized water piping from the main all the way throughout the building and that is the reference of thinking I am using. I haven't seen any PEX used in this area.
There is nothing wrong with parallel EGC's as long as they are one of the types allowed by 250.118, which copper tubing is not.
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