Hot water pipe of water heater need bond ?

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Curiousv

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House is plumbed with galvanized pipe - cold water pipe already has bond to ground via a whip cable.
This is 240V electric water heater -

Do I need to connect hot water pipe to cold water pipe (I mean do I need to bond hot water pipe to ground?)

I am asking because somewhere I read - if you connect hot water pipe to other pipe or other wires - the wires will get hot and may cause fire?

If you suggest I should bond hot pipe as well - please check link - of https://www.amazon.com/gp/product/B09XFDJCFD
is that type of connector is good enough? and wire should be any 12 or 10 gauge is fine?

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John Gayewski

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I think you just need one grounding bond on your piping. Your water heater should have a ground wire on it hooked up on the panel just from the normal wiring.
 

Curiousv

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I think you just need one grounding bond on your piping. Your water heater should have a ground wire on it hooked up on the panel just from the normal wiring.
I am not sure if if water heater itself has ground wire on it that goes directly to panel. But cold supply line has ground wire hooked up and also cold line to washer has two 4 gauge wires hooked on to cold supply line.
 

LLigetfa

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I think you just need one grounding bond on your piping. Your water heater should have a ground wire on it hooked up on the panel just from the normal wiring.
What if there is a dielectric union? I think those should be jumpered around. Bonding uses #6 wire.
 

John Gayewski

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What if there is a dielectric union? I think those should be jumpered around. Bonding uses #6 wire.
Yeah there are probably a few factors that can cause someone to want to ground their hot water piping.
 

LLigetfa

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I am asking because somewhere I read - if you connect hot water pipe to other pipe or other wires - the wires will get hot and may cause fire?
If there is so much stray current to make the wire hot and start a fire, then you have bigger problems and having an energized hot water pipe could kill you. The purpose and size of ground wire is to pass enough current to trip the breaker that is supplying the current.

Decades ago I was servicing a municipal cardlock fuel pump system. The service feed to the building had an open neutral so all of the current was being carried by the protection ground bonded to the copper water supply. There was so much current that it warmed the incoming cold water.
 

Curiousv

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Yeah there are probably a few factors that can cause someone to want to ground their hot water piping.
So should I connect #6 jumper wire between hot and cold (to bond hot to ground?) and I gave u two links ..one is zinc ..will that be good enough?
 

Curiousv

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If there is so much stray current to make the wire hot and start a fire, then you have bigger problems and having an energized hot water pipe could kill you. The purpose and size of ground wire is to pass enough current to trip the breaker that is supplying the current.

Decades ago I was servicing a municipal cardlock fuel pump system. The service feed to the building had an open neutral so all of the current was being carried by the protection ground bonded to the copper water supply. There was so much current that it warmed the incoming cold water.
I meant to say hot water pipe will transfer heat to circuit (not because stray current) - that is what I read and that is why the author advised not to bond hot water pipe - what do u think ....should I bond hot water pipe or not?
 

John Gayewski

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I meant to say hot water pipe will transfer heat to circuit (not because stray current) - that is what I read and that is why the author advised not to bond hot water pipe - what do u think ....should I bond hot water pipe or not?
In gonna doubt you need it. If your plumbing is old enough to be galvanized your piping is connected to each other and already bonded to ground.
 

wwhitney

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should I bond hot water pipe or not?
There's no downside to doing so.

If the hot water piping is metallic, it's required to be bonded. Perhaps it's bonded through the metallic tank water heater to the cold water side, or perhaps there's a dielectric nipple preventing that. Perhaps it's bonded to the water heater's electrical supply's EGC, or perhaps not. If it's not already bonded, you need to add a bonding jumper. Since the other bonds are uncertain, around here inspectors request an explicit bonding jumper from hot to cold at the water heater--then there's no uncertainty.

Cheers, Wayne
 

Tuttles Revenge

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There's no downside to doing so.
Agreed.

I meant to say hot water pipe will transfer heat to circuit (not because stray current) - that is what I read and that is why the author advised not to bond hot water pipe - what do u think ....should I bond hot water pipe or not?
Heat / Energy will transfer through metallic anything.. But not in any signifigant way. And if your jumper from hot to cold were to go upwards 6 inches then down and connect in a big bow... the heat will not transfer Down to the cold. Similar to how a Heat trap works in water heater supplies. I've never tested this because I've never once heard of this question before.

In any portion of the piping system, the heat transfer would be so minimal regardless to be not measurable. The time that the water is hot in the hot side and able to transfer any bit of heat would be so miniscule. Then the water cools and the cold water moves and all that goes away...
 
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wwhitney

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And if your jumper from hot to cold were to go upwards 6 inches then down and connect in a big bow... the heat will not transfer Down to the cold. Similar to how a Heat trap works in water heater supplies.
That part is not correct. Only convective heat transfer is affected by gravity, and only in fluids. So hot air and hot water rise, due to the movement of the hot fluid itself. Since copper is a solid, there's no convective heat transfer within the copper wire. It's all conduction, and the orientation of the copper wire won't affect conductive heat transfer.

But the conducted heat from a jumper on a hot water pipe to anywhere else in the electrical system will be negligible.

Cheers, Wayne
 

Tuttles Revenge

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That part is not correct. Only convective heat transfer is affected by gravity, and only in fluids. So hot air and hot water rise, due to the movement of the hot fluid itself. Since copper is a solid, there's no convective heat transfer within the copper wire. It's all conduction, and the orientation of the copper wire won't affect conductive heat transfer.

But the conducted heat from a jumper on a hot water pipe to anywhere else in the electrical system will be negligible.

Cheers, Wayne
Yeah... I was just figuring that out in my head after I typed it..
 

Curiousv

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That part is not correct. Only convective heat transfer is affected by gravity, and only in fluids. So hot air and hot water rise, due to the movement of the hot fluid itself. Since copper is a solid, there's no convective heat transfer within the copper wire. It's all conduction, and the orientation of the copper wire won't affect conductive heat transfer.

But the conducted heat from a jumper on a hot water pipe to anywhere else in the electrical system will be negligible.

Cheers, Wayne
ok does it need #6 or #4 gauge ? circuit is 12 gauge - so can I use #12 wire ? or can I twist multiple #12 ground wires together and use that way?
also can is it ok to use ground clamp made from a zinc ? or it has to be copper alloy only? I have given links on original post
 

wwhitney

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On sizing, see NEC 250.104(A)(1), which directs you to Table 250.102(C)(1). The minimum size depends on the size of your service conductors.






As to the clip you linked to, it's from a reputable manufacturer and the product description tells you where it can be used. The zinc one will be above ground only, I would think, which is fine for your application.


Cheers, Wayne
 

Curiousv

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On sizing, see NEC 250.104(A)(1), which directs you to Table 250.102(C)(1). The minimum size depends on the size of your service conductors.






As to the clip you linked to, it's from a reputable manufacturer and the product description tells you where it can be used. The zinc one will be above ground only, I would think, which is fine for your application.


Cheers, Wayne
Well from table - I need at the min. #8 copper wire - because there is nothing smaller mentioned in table. ...wow
 

wwhitney

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Well from table - I need at the min. #8 copper wire - because there is nothing smaller mentioned in table. ...wow

Well, you did see that I said it was based on the size of the service conductors, not the water heater circuit? So if your service conductors are #2 Cu or smaller, i.e. your service is 125A or less, then you could use a #8. Usually it's more practical to use a #6 or #4. If you have a 200A service, i.e. #2/0 Cu service conductors, then you'd need a #4.

Cheers, Wayne
 
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