Info re hydromasssage tub bonding

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electricmanscott

electricmanscott

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Boston, MA
Hydromasssage tub bonding is pretty basic and for most installations nothing is required. Imo the only bonding required is for grounded metal parts and metallic piping in contact with the circulating water. If the supply lines are copper people typically bond them which is unnecessary because they aren't in contact with the circulating water.

I'm pretty sure there's been info posted here in the past that backs my view. Does anybody have anything on this?
 
My experience has been that 680.74 is pretty sight-forward, howver, 110.3(B) can muddy the waters (no pun intended)a bit. I still find some "Jacuzzi" brand tubs that have install instructions calling for a bond from the pump back to the electrical panel.

[FONT=&quot] Jacuzzi Whirlpool Bath K339000X 3/06[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]With a #8 solid copper wire, bond the heater to the house electrical panel or approved local bond. A bonding lug is provided on the heater. With another #8 solid copper wire, bond the pump/motor to the house electrical panel or approved local bond. A bonding lug is provided on the pump/motor.[/FONT]
 
The 2014 NEC attempted to clear this up, unless you run into something like Augie mentioned:

17-148 Log #2736 NEC-P17 Final Action: Accept
(680.74)
________________________________________________________________
Submitter: Robert Meier, Norwood, NJ
Recommendation: Revise text to read as follows:
680.74 Bonding
Both metal piping system and all grounded metal parts in contact with the
circulating water shall be bonded together using a solid copper bonding jumper,
insulated, covered, or bare, not small than 8 AWG. The bonding jumper shall
be connected tot eh terminal on the circulating pump motor that is intended for
this purpose. The bonding jumper shall not be required to be connected to a
double insulated circulating pump motor. The 8 AWG or larger solid copper
bonding jumper shall be required for equipotential bonding in the area of the
hydromassage bathtub and shall not be required to be extended or attached to
the remote panelboard, service equipment, or any electrode. The 8 AWG or
larger solid copper bonding jumper shall be long enough to terminate on a
replacement non-double-insulated pump motor and shall be terminated to the
equipment grounding conductor of the branch circuit of the motor when a
double-insulated circulating pump motor is used.
Substantiation: There seems to be much confusion with the present wording
of this requirement. Inspectors and installers seem to believe that the two parts
of the first sentence, All metal piping systems and all grounded metal parts in
contact with the circulating water are two separate requirements. Because of
this they take the first part All metal piping systems out of context and require
the pump to be bonded to the hot and cold metallic water piping that feeds the
hydromassage tub faucet. If the intention of this section were to take the first
two parts of the sentence as two separate requirements then there would need
to be some additional wording that would say exactly where the All metal
piping systems that are required to be bonded are located within the structure.
When taken as two separate parts, it would mean that every metal piping
system within the structure would be required to be bonded to the pump motor.
This would include the hot and cold metallic water lines, metallic gas piping
systems and any other metallic piping system within the structure. changing the
first sentence will clarify that the requirement is solely for metal piping
systems and grounded metal parts that contact the circulating water and not the
piping used to fill the tub or any other metallic piping systems that may or may
not be in the vicinity of the hydromassage tub.
Panel Meeting Action: Accept
Panel Statement: The panel clarifies that the word ?Both? replaces the
existing word ?all? at the beginning of the first sentence. Otherwise, only the
changes shown in legislative text are intended.
Number Eligible to Vote: 10
Ballot Results: Affirmative: 10
Click to expand...
 
I don't think it is very clear but if I remember correctly the cmp panel at our meeting last year said if there were metal water lines feeding the tub then there should be a bond between the pump and the water lines. It makes sense to me to have all the metal at the same potential.
 
augie47 said:
My experience has been that 680.74 is pretty sight-forward, howver, 110.3(B) can muddy the waters (no pun intended)a bit. I still find some "Jacuzzi" brand tubs that have install instructions calling for a bond from the pump back to the electrical panel.

Jacuzzi Whirlpool Bath K339000X 3/06

With a #8 solid copper wire, bond the heater to the house electrical panel or approved local bond. A bonding lug is provided on the heater. With another #8 solid copper wire, bond the pump/motor to the house electrical panel or approved local bond. A bonding lug is provided on the pump/motor.
Click to expand...


Jacuzzi is saying here [red hi-lite] that the local water pipes are OK...as directed by the NEC; I do not see a mandate to go to the service. The 'approval' is per code.
 
Dennis Alwon said:
I don't think it is very clear but if I remember correctly the cmp panel at our meeting last year said if there were metal water lines feeding the tub then there should be a bond between the pump and the water lines. It makes sense to me to have all the metal at the same potential.
Click to expand...

I think the substantiation posted makes it very clear. I used it twice this week to explain to two different inspectors why there was nothing connected to the lug on the motor.
 
electricmanscott said:
I think the substantiation posted makes it very clear. I used it twice this week to explain to two different inspectors why there was nothing connected to the lug on the motor.
Click to expand...


And I can read that as bond the heater to the house panel or bond the heater to an approved bond. In either case it would be bonded.
 
Dennis Alwon said:
I don't think it is very clear but if I remember correctly the cmp panel at our meeting last year said if there were metal water lines feeding the tub then there should be a bond between the pump and the water lines. It makes sense to me to have all the metal at the same potential.
Click to expand...
FWIW, I once had an inspector tell me that if I connected the # 8 solid to the cold water line under the tub that the clamp had to be accessable for servicing. Not sure if it's that explicit in the Code but it made sense to me at the time. If that ground clamp somehow became corroded you would have to be able to access it, clean the connection or replace the clamp. There are also some tubs that come with a double insulated motor and no ground lug on the motor. I would still install the # 8 wire in the event that motor ever gets swapped out for a std. motor.
 
Dennis Alwon said:
I don't think it is very clear but if I remember correctly the cmp panel at our meeting last year said if there were metal water lines feeding the tub then there should be a bond between the pump and the water lines. It makes sense to me to have all the metal at the same potential.
Click to expand...

It makes sense to bond the pump and the water lines and stop there, theory-wise? :angel:

Just pointing out your first statement and last statement are not the same thing. :)
 
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