Bonding motor for jetted tub

[AZsparky]

Please help clarify....Have a Master bedroom located jetted tub with two pumps. One is inaccessible and unable to be seen the other has a bonding lug that is on the far side of the pump motor and this one has metal parts to the motor housing. The tub has all plastic piping around the tub. BUT when I went inside and voltage tested (one lead from the bathroom receptacle hot, and the other lead to the metal jetted tub spout, I was reading 101 volts. My question is: Do these motors need to be bonded at all? Visually, I can't see any metal piping, but I can not see (don't have access to) the stubs to the faucet handles. The original installer only put in a 12 x 12 access panel on the outside of the house.

 

[infinity]

Is this a hydromassage tub with the metal piping part of the water circulation system or is just used to fill the tub?

 

[AZsparky]

All the piping to the jets is plastic. Since I am measuring the 101 volts from a nearby receptacle's hot to the tub metal fill spout, there must be some ground path. I can't see the piping to the fill lines, but I would assume it is copper based on past experience. In summary, all pipe recirculating the water is plastic and the fill lines are probably copper. Do the pump motors (with metal cases) need to be bonded in this case? It will be almost impossible to do the way it is installed. Equipment grounds are intact.

 

[hurk27]

All the piping to the jets is plastic. Since I am measuring the 101 volts from a nearby receptacle's hot to the tub metal fill spout, there must be some ground path. I can't see the piping to the fill lines, but I would assume it is copper based on past experience. In summary, all pipe recirculating the water is plastic and the fill lines are probably copper. Do the pump motors (with metal cases) need to be bonded in this case? It will be almost impossible to do the way it is installed. Equipment grounds are intact.

These are called a Hydromassage bathtub, they are covered by section VII or article 680, and yes unless the motors are double insulated they are required to be bonded to each other and to any metal water pipes serving the tub,, it also requires that all electrical equipment must have adequate access, which the home owner will need anyway because pumps don't last forever, so you have two code violations that need to be addressed.

Here is what the 2008 says:

680.73 Accessibility. Hydromassage bathtub electrical
equipment shall be accessible without damaging the building
structure or building finish.

680.74 Bonding. All metal piping systems 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 smaller than 8 AWG. The bonding
jumper shall be connected to the 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 any remote panelboard,
service equipment, or any electrode.

Note that this equal potential bond conductor does not have to be extended back to the service panel.

Also sometimes you can make access to the back motor from underneath if this is not up in a second story bath, but access must be made or they are going to have trouble when the motor needs servicing or replacing.

I too hate when I have to solve a problem that the original EC failed to do when it would have been much easier, but use it to make money, or tell the home owner to land it back in the original EC's lap by contacting the inspectors who inspected the job, inspectors can't always catch everything but at least now they will know to be on the lookout for this EC work.

 

[infinity]

These are called a Hydromassage bathtub, they are covered by section VII or article 680, and yes unless the motors are double insulated they are required to be bonded to each other and to any metal water pipes serving the tub,, it also requires that all electrical equipment must have adequate access, which the home owner will need anyway because pumps don't last forever, so you have two code violations that need to be addressed.
.

If the metal piping is just used to fill the tub and is not part of the water circulation system then it is not required to be bonded to the pump.

 

[kwired]

Please help clarify....Have a Master bedroom located jetted tub with two pumps. One is inaccessible and unable to be seen the other has a bonding lug that is on the far side of the pump motor and this one has metal parts to the motor housing. The tub has all plastic piping around the tub. BUT when I went inside and voltage tested (one lead from the bathroom receptacle hot, and the other lead to the metal jetted tub spout, I was reading 101 volts. My question is: Do these motors need to be bonded at all? Visually, I can't see any metal piping, but I can not see (don't have access to) the stubs to the faucet handles. The original installer only put in a 12 x 12 access panel on the outside of the house.

Why are you measuring from the receptacle "hot" terminal to anything in/around the tub? You should expect to see voltage, if anything the fact you do not read full 120 volts means the spout is not solidly grounded. But the whole idea of equipotential bonding is so that whatever is within reach of a user of the tub all remains at the same potential. The pump motors are already grounded via the equipment grounding conductor of the circuit supplying them. The lug provided on the motor is for equipotential bonding of items near the tub - such as the water piping if it is metallic, this puts the user of the tub who may be immersed in water in the tub that is electrically at same potential as the pump because same water in the tub is also being piped to the pump at same potential as anything that is also bonded to the pump.

 

[infinity]

Why are you measuring from the receptacle "hot" terminal to anything in/around the tub? You should expect to see voltage, if anything the fact you do not read full 120 volts means the spout is not solidly grounded. But the whole idea of equipotential bonding is so that whatever is within reach of a user of the tub all remains at the same potential. The pump motors are already grounded via the equipment grounding conductor of the circuit supplying them. The lug provided on the motor is for equipotential bonding of items near the tub - such as the water piping if it is metallic, this puts the user of the tub who may be immersed in water in the tub that is electrically at same potential as the pump because same water in the tub is also being piped to the pump at same potential as anything that is also bonded to the pump.

Where is 680.74 does it say that you need to provide equipotential grounding for anything metal near the tub? It says that the piping and metallic parts used for the water circulation system are required to be bonded but nothing else. Here's the 2014 wording which has a slight change to the wording for clarification:

680.74 Bonding. Both metal piping systems and grounded
metal parts in contact with the circulating water shall be
bonded together using a solid copper bonding jumper, in-
sulated, covered, or bare, not smaller than 8 AWG. The
bonding jumper shall be connected to the 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 bath-
tub and shall not be required to be extended or attached to
any remote panelboard, service equipment, or any elec-
trode. The 8AWG 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 equip-
ment grounding conductor of the branch circuit of the motor
when a double-insulated circulating pump motor is used.

 

[AZsparky]

This doesn't sound good.

This doesn't sound good.

The reason I measured from the hot at the bathroom receptacle to the fill spout on the hydromassage tub was to see if the piping to the spout and on/off handles had metallic pipe to it, thinking it may be PEX or something non-metallic. Since I was reading ~101 volts, I assume it had to be metallic with somewhat of a ground path, but I just can't get a visual on it. Yes, the initial install was horrible with no real access to anything but the GFI receptacle that the pumps plug into, and 1 of the circulating pumps. The bonding lug for the pump that can be seen is on the farthest side of the pump and can only be seen with an inspection mirror. The other pump can't even be seen from the access panel. So, IF JUST the fill lines are copper, this means that both motors need to be bonded if they are not double insulated, regardless if the recirculating lines are all just PVC. Correct??? Someone looking in the access opening would have no idea if the tub had any metallic piping to it at all. Thanks to all for taking the time to respond and your thoughtful input.

 

[AZsparky]

Changing supply lines

Changing supply lines

If the motors need to be bonded just because of the copper fill lines, the easiest fix may be to open the wall and splice in PEX to the valves? Or just say that no metallic piping was visible, therefore no equipotential bonding required?

 

[kwired]

Where is 680.74 does it say that you need to provide equipotential grounding for anything metal near the tub? It says that the piping and metallic parts used for the water circulation system are required to be bonded but nothing else. Here's the 2014 wording which has a slight change to the wording for clarification:

I admit to not looking before replying, but to answer your question it says exactly what you question within that in the section:?:?:

680.74 Bonding. Both metal piping systems and grounded
metal parts in contact with the circulating water shall be
bonded together using a solid copper bonding jumper, in-
sulated, covered, or bare, not smaller than 8 AWG. The
bonding jumper shall be connected to the 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 bath-
tub and shall not be required to be extended or attached to
any remote panelboard, service equipment, or any elec-
trode. The 8AWG 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 equip-
ment grounding conductor of the branch circuit of the motor
when a double-insulated circulating pump motor is used.


However it does only specify metal piping systems and grounded metal parts in contact with circulating water, unlike the general rules for pools that require most any metallic item in a certain distance of the pool to be bonded together. Maybe my bad for not checking this, but my intent was to answer the OP's question of "Do these motors need to be bonded at all?". The lug is not there to bond the motor, the lug is there to bond other items to the motor.

Do the two motors need additional bonding to each other? That is a good question, and maybe what he meant to ask.

I'd say if both motors are part of a listed packaged assembly they shouldn't need additional bonding to anything within the listed packaged assembly. If the are two components of an assembly that is not a listed packaged assembly then they likely should be bonded together.