Bonding of W/P pump motor?

[ctroyp]

This is a question that I have searched for on this site and found many topics, but all of the answers have been somewhat indirect.

My question is: In a residence, what is the correct way to bond a W/P pump motor to the cold water line when the house is plumbed in plastic? There is only a couple feet of copper installed at the valves.

A. Run an 8 awg from the motor lug to the copper at the valves.
B. Run an 8 awg from the motor lug back to the panel?
C. Run an 8 awg from the motor lug to the accessible 5' of copper entering the basement.
D. None of these, I want to give my own answer...

In addition, our local AHJ requires an additional ground rod at the service when the plumbing is in plastic. Is this common/uncommon in your area?

 

[bphgravity]

Re: Bonding of W/P pump motor?

D. I don't feel your particular example requires bonded at all. I don't think it qualifies under 250.104? I suppose if you feel there is a possibilty that this section of the piping may become energized, then you could install a bonding jumper sized per Table 250.122 and take it to the grounding electrode system.

 

[ctroyp]

Re: Bonding of W/P pump motor?

I don't have the pump's installation manual for this particular W/P yet, but don't some manufacturers require the pump to be bonded? If so, back to the original question.

 

[bphgravity]

Re: Bonding of W/P pump motor?

I don't know what a "W/P" is, but if the pump housing needs to be bonded, it can be done with the EGC run with the branch circuit conductors serving the pump.

 

[ctroyp]

Re: Bonding of W/P pump motor?

Sorry, whirlpool.

 

[bphgravity]

Re: Bonding of W/P pump motor?

Ahh, that changes everything.

I still say D. I don't believe Article 680 requires the bonding of metallic parts at a spa or hottub to be extended back to service equipment, grounding electrodes, etc.. Whatever metal parts are assoicated with the spa should be bonded together with #8 solid and your done. See section 680.43(D) and 680.26

P.S. By "whirlpool", I take that to mean a spa or hottub, if you are talking about a hydromassage tub, the requirement is the same, but found in Section 680.74

[ October 27, 2004, 12:00 PM: Message edited by: bphgravity ]

 

[ctroyp]

Re: Bonding of W/P pump motor?

Thanks for your input. The whirlpool is a standard corner tub with jets. So would this be considered a hydromassage tub? To my knowledge the code doesn't refer to a whirlpool tub as whirlpool but instead as hydromassage. Correct me if I'm wrong.

Would you want to take a shot as to why the AHJ would want a second ground rod when plastic plumbing is run?

 

[bphgravity]

Re: Bonding of W/P pump motor?

Yes, "whirlpool" is a manufacturer's name.

Second ground rod - Possibly to meet the requirement of Section 250.56?

 

[ctroyp]

Re: Bonding of W/P pump motor?

I don't understand why they require it just because there is plastic plumbing in the house. Having an additional rod would only give redundency. Not that it's a bad thing but what is the significant difference between a house that has plastic plumbing and a house that has copper. Another question, the water pipe bond, is it there to bond all of the copper that runs through the house or to serve as another means to earth ground?

 

[ryan_618]

Re: Bonding of W/P pump motor?

I would say "A".

"B" and "C" can be addressed by reading the fine print note to 680.26. I realize that this is a hydromassage tub and not a swimming pool, but the objective of equipotential bonding is the same in both cases.

The rebuttal to "A" would be that 680.74 states "metal piping system". The question then becomes "what is a metal piping system. I would bond from the motor to the valve with $0.75 worth of copper and wash my hands of the whole thing.