Spa tub motor bonding?

Ok, I’ve called out the last two spa tubs I’ve inspected for not having the proper cold water bonding in place. Each has had a metal motor casing with an “Empty” bonding clamp and or lug clearly visible on the motor. The agent informs me today that an independent licensed electrical contractor inspected and determined that the motors were of a sealed design and did not require bonding.

I’m totally confused, I thought any and all metal within 5’ of a electrically supplied pool, spa, spa tub, etc. had to be bonded.

Any thoughts?

If the motor is double insulated, it need not be bonded.

When I see an empty bonding lug, I call it out (assuming the supply piping is metallic), and let the sparky determine if the motor is double insulated.

Thanks Jeff,

Each of these structures has had copper fresh water plumbing.

Just for the sake of asking, why does the OEM equip any motor that doesn’t require bonding, with a bonding lug?

Good question, but I don’t know the answer :smiley:

Was the spa tub piping metal or plastic?

Plastic, I haven’t seen any metal on bathroom spa tubs for many years. The supply plumbing to the faucets was copper.

That was my first thought as well. I’ll look forward to seeing the answer from the ‘experts’.

Where’s Paul, Greg and or Speedy when you need’em?:wink:

My guess would be mass production…costs more to remove it.

To be honest I have not seen a D-I motor with bond lug.
If the lug is present, I use it.

I second that. I have never seen a double insulated motor with a bond lug on any pool, spa, tub or whatever. I think the spark was blowing smoke.

The answer is always supposed to be on the label. U/L has a marking guide for pool/spa motors, just like most equipment and that defines what they have to list there.

The 2005 NEC Handbook reminds us in the commentary to 680.21(B) that attempting to bond a double insulated motor compromises the double insulated properties. Sort of a no-brainer, when you think about it. I can say with reasonable certainty that a a motor with a factory bond lug is not double insulated.

…pump[s] incorporating a system of double insulation are grounded; however, they are not required to be incorporated into the bonding system required by 680.26(B), since the act of bonding compromises the double-insulation system.

Always appreciate learning from you guys…:smiley:

What would you bond it to if the plumbing is plastic and there is no other metal parts large enough to require bonding?

Nothing. Consider this… the purpose of bonding is so that all the metal parts are at the same potential. If there’s only one metal thing (the motor) then it’s already at the same potential as itself, if you get what I mean. No other metal to bond to… no remediation required. Quite often in the case of spas and some whirlpool tubs, both the motor and the heater unit both have a bond lug. You at least connect these two together if there’s no metal pipework. There’s a more recent requirement that the paved surface under the hot tub have bonding provisions, but that’s gonna be an ugly conversation if anyone wants to go there.

You have to be careful not to confuse spas and theraputic bathtubs. The rules are softer on a bathtub.
Marc is referring to 680.26© that is talking about spas and pools. All “paved surfaces” within 3’ from the water need to be bonded. (NEC2005)


The jet nozzle plumbing is plastic, but the adjacent fresh water supply plumbing to the faucet fixtures was copper. I’ve always been instructed if a bonding lug was present a #8 AWG wire should be installed in the form of bonding to the metal cold water plumbing system.

Sounds as though we’re in agreement, if an empty lug is present, further inspection/evaluation by a licensed electrical contractor is prudent.


I would bet even if the piping was plastic, the faucet handles were metal.