Proper bonding across CPVC pipe

[OldOak]

My house has a well and the water lines are copper with the exception of some of the upstairs bathroom. There is currently a bonding wire that is clamped on shortly after the water softener and runs to the electrical panel.

I'm going to be replacing the water softener- which currently uses brass valves, with new plastic fittings. I know I need a bonding kit to jump from copper pipe to copper pipe since the new softener and fittings will break the electrical bond.

My question is this- if I were to replace several feet of pipe around the water softener with PEX or CPVC to install some new sediment filters, is it acceptable to jump from the existing house copper pipe to the main water line coming in from the well to maintain continuity? It might be 5-10 or so feet of copper pipe I'd be replacing and would need to bond across. The original bonding wire running to the electric panel would not be disturbed by this install, it would be on the "house" side of the copper pipe.

I see kits that come with 2' of copper wire, but did not know if I could use similar gauge clamps and wire to cover a large break of say 5-10 feet of plastic pipe to maintain continuity.

Thanks for any info you can provide.

 

[wwhitney]

There is currently a bonding wire that is clamped on shortly after the water softener and runs to the electrical panel.

That wire needs to be connected to the metal water pipe within 5' of its entering the building. before any removable equipment like a water softener. Depending on other details of your electrical grounding, it may need to be continuous without splices. But a water pipe can't be your only grounding electrode, and so you should have some ground rods or a connection to your concrete foundation. If one of those connections is continuous without splices, that satisfies the requirement, and your water pipe connection can have a splice in it.

I see kits that come with 2' of copper wire, but did not know if I could use similar gauge clamps and wire to cover a large break of say 5-10 feet of plastic pipe to maintain continuity.

For jumping across breaks in the metal water pipe, you just need two grounding clamps and a length of copper wire. (Could be bare solid, could be insulated, color doesn't matter). The size depends on the main breaker in your service panel (I believe), and if it's 100A or less, the minimum size is #8 Cu, or for 200A or less, #6 Cu. But often #4 is used as the rules for routing and protection are a bit more lenient (I believe).

Cheers, Wayne

(I believe means I may be mixing up requirements for bonding jumpers and grounding electrode conductors, but probably not in a non-conservative way.)

 

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[OldOak]

That wire needs to be connected to the metal water pipe within 5' of its entering the building. before any removable equipment like a water softener. Depending on other details of your electrical grounding, it may need to be continuous without splices. But a water pipe can't be your only grounding electrode, and so you should have some ground rods or a connection to your concrete foundation. If one of those connections is continuous without splices, that satisfies the requirement, and your water pipe connection can have a splice in it.


For jumping across breaks in the metal water pipe, you just need two grounding clamps and a length of copper wire. (Could be bare solid, could be insulated, color doesn't matter). The size depends on the main breaker in your service panel (I believe), and if it's 100A or less, the minimum size is #8 Cu, or for 200A or less, #6 Cu. But often #4 is used as the rules for routing and protection are a bit more lenient (I believe).

Cheers, Wayne

(I believe means I may be mixing up requirements for bonding jumpers and grounding electrode conductors, but probably not in a non-conservative way.)

Thanks for your reply. So, interesting development. I went behind the well tank to see if there was any grounding attachment I had missed, and I discovered the pipe coming into the house from the well head is actually PVC, not copper. It had a sleeve on it to stop condensation and I assumed it was also copper.

Considering this, I could easily start at the well tank with CPVC or PEX, connect it to the water softener and the line coming out of the softener could also be the same, transitioning back to copper right where the existing bonding wire is clamped and travels back to the main electric panel. Perhaps that's why it was connected that way rather than to a ground rod in the first place- the main water supply line isn't metal. Does that make sense?

 

[wwhitney]

Sure. If there's no underground metal water piping, then (1) from my earlier post doesn't apply. You just need to bond everything, which the wire to the metal piping after the water softener is presumably doing. So all you need to do is maintain that, and add jumpers if you create further disruptions in the continuity of the metal portion of the water piping.

Cheers, Wayne

 

[Reach4]

I am thinking the proponents of a bonding wire across hot and cold suggest that to protect the water heater, are only concerned when metal pipes are connected to the WH.

Modern electric wiring uses something other than the path thru a water heater to provide the earth grounding. There is at least one ground rod to connect to the breaker panel. If the installation is old, and uses the metal water piping from the well as a ground, I don't expect that path needs to be maintained through the WH. I think the bypassing could be needed on cold until the connection to the breaker panel.

So I think that a bonding wire for a gas water heater is not needed or suggested. I would like to hear other opinions on that.

I think your metal casing and metal well cap are supposed to be grounded for new stuff.

 

[wwhitney]

Ground has two different meanings, earthing and bonding, and it's helpful to separate them.

Earthing just means connecting something to the earth. That's done through a grounding (earthing) electrode, such as a ground rod, a metal well casing, a concrete encased electrode (foundation), a metal underground water pipe, or some other types. The NEC tells you that all available electrodes at a structure should be interconnected, and specifies a minimum electrode system that you need to add absent other electrodes (namely, two ground rods).

Bonding is the intentional connection of metal parts that should not be carrying current to each other, to earth, and to the grounded (earthed) electrical system conductor when present (some electrical systems are ungrounded, but you won't run into that at a residence). This puts them all at ground (earth) potential. And if an ungrounded (live) conductor faults to the metal parts, the circuit breaker should trip (when the electrical system is grounded), rather than leaving the metal parts energized.

So that dichotomy represents the split in my original answer. If there's a metal underground pipe, you need to use it as a grounding electrode for earthing, part (1). But all metal piping systems need to be bonded, part (2). The reason you often see a bonding jumper at a water heater from hot to cold metallic piping is a lack of confidence that bonding continuity will be maintained via the water heater itself. E.g. because of dielectric fittings.

Cheers, Wayne

P.S. Historically, when the NEC started requiring that receptacles be grounded (having an EGC (bonding) pin), there was an allowance to add the EGC to ungrounded (without EGC) circuits by running the EGC to the closest point on the metallic water piping. That is no longer allowed, but if you have receptacles that were installed using that allowance, maintaining the continuity of the metal water piping system is important for the safe use of those receptacles.