copper pipes under mobile home (doublewide)

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reed50

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I went under my home to see how things were and saw something I hope you guys can help me with since you all were a big help about bonding the copper pipes (with there being plastic inserted in places). The copper pipes under the house are hung from the steel frame by metal clamps, and there is a copper wire running from one pipe to the frame. Is that wire for bonding purposes? Didn't know it was there. Once again, any help is very appreciated.
 

JWelectric

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Yes, without much doubt this was an attempt to bond the pipes to the service. Unless the copper pipes are a complete system then there is no requirement to bond the pipe to the service. Any non-metallic piping at all and there is no more need to bond.

Back in the early eighties and before it was required that metallic water piping systems were to be made electrically continuous. With the introduction and lower cost on non-metallic piping systems NFPA saw there was no way that they could take power of the plumbers and if the metal is not electrically continuous from one end to the other what would be the purpose of bonding anything?
 

hj

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IT should be the other way around. IF the metal piping were continuous, then it also was contiguous with the metal pipe in the ground which provided the ground/bond. WHEN there was NOT a metal underground line, here the electrical panel had to be labeled "Non-metallic water service pipe", so everyone knew NOT to rely on the water piping for grounding. ANY partial sections of metal pipe COULD be energized, so they SHOULD be bonded.
 

JWelectric

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IT should be the other way around. IF the metal piping were continuous, then it also was contiguous with the metal pipe in the ground which provided the ground/bond. WHEN there was NOT a metal underground line, here the electrical panel had to be labeled "Non-metallic water service pipe", so everyone knew NOT to rely on the water piping for grounding. ANY partial sections of metal pipe COULD be energized, so they SHOULD be bonded.

There is absolutely no reason to bond a short piece of metal water pipe under a house. Just what is likely to energize that pipe? Unless there is something wired to that pipe such as a water heater then there is nothing that is likely to energize it. If the water heater did somehow energize the water heater then the equipment grounding conductor that is installed with the branch circuit will carry any fault current back to the service.

When connecting a system to earth using such items as ground rods or metal water pipe the only reasons this connection is made is as follows;
250.4 General Requirements for Grounding and Bonding.
The following general requirements identify what grounding and bonding of electrical systems are required to accomplish. The prescriptive methods contained in Article 250 shall be followed to comply with the performance requirements of this section.
(A) Grounded Systems.
(1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation.

When a metal water pipe is in contact with earth it is the grounding electrode conductor that does the bonding of the metal water pipe not the fact that it is connected to earth.
 

reed50

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I apologize if I haven't been clear on what we have. There is plastic pipe coming underground to the doublewide. The cheap grey pipe that came with the home was replaced with copper pipe. (There is no copper pipe in the ground). All pipe running under the house is copper. All three bath sinks and both toilets have plastic running from the floor up. Copper runs to the water heater, washing machine and both showers (except for a 18 - 24 inch insertion of plastic pipe going to one shower).
 

JWelectric

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I apologize if I haven't been clear on what we have. There is plastic pipe coming underground to the doublewide. The cheap grey pipe that came with the home was replaced with copper pipe. (There is no copper pipe in the ground). All pipe running under the house is copper. All three bath sinks and both toilets have plastic running from the floor up. Copper runs to the water heater, washing machine and both showers (except for a 18 - 24 inch insertion of plastic pipe going to one shower).

You have been perfectly clear to me.

You said that the pipes were not in contact with earth for 10 feet or more therefore there is no grounding electrode present. No electrode no need for a grounding electrode conductor from the service to the first five feet of where the water comes out of the ground.

You have said on many occasions that the copper is not a complete copper piping system and that you can see non-metallic pipe installed. Therefore there is no requirement to bond this pipe as outlined in 250.104(A).

You have said that the copper is installed to the frame of the mobile home and the frame is bonded to the service so here is one path for current to return to the service.

You said that it is a mobile home and that it has a water heater so this water heater is going to be an electric heater which has an equipment grounding conductor connected to the water heater which is connected to the water system providing another return path for current should something happen.

I say again to stop worrying about connecting this copper pipe to anything. It does not need any bonding and damn sure don’t need to be connected to earth or grounded if you prefer saying it that way.
 
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