Hot Tub Bonding

[sparky_magoo]

I installed a sub panel for a hot tub today. It is a Homeline 125A 12/24. It has a 60 amp main breaker. It is installed on a detached cinderblock wall. Th wall conceals the pool equiptment. It is a natuaral gas fired hot tub. The cinder block wall is L shaped. Inside of the L, I found some rebars stubbed up. I asked the super if this is where I bond to the grid. He said no, bond to this 8 AWG thwn protruding through a 1 inch PVC stubbed up nearby.

I have two questions.

Was it necessary to beat down the ground rod I drove today? Would bonding to the # 8 have been sufficient?

Is a # 8 large enough to act as my GEC, for the grid?

The initial EC was fired. We inherited this job as a T & M project. The sub panel was supposed to be 100 amps, but the feeder wasn't large enough. I have already down-sized the breaker.

 

[celtic]

Was it necessary to beat down the ground rod I drove today? Would bonding to the # 8 have been sufficient?

Is a # 8 large enough to act as my GEC, for the grid?

250.52(A)(3)

Direct your attention over here (Footing on an addition?) for a moment.

The rods ARE neccessary as the #8 is not correct (#4 min. required as well as 20' min of 1/2" rebar)
If you can change that #8 to a #4....


Am I on the right page?

 

[stickboy1375]

I installed a sub panel for a hot tub today. It is a Homeline 125A 12/24. It has a 60 amp main breaker. It is installed on a detached cinderblock wall. Th wall conceals the pool equiptment. It is a natuaral gas fired hot tub. The cinder block wall is L shaped. Inside of the L, I found some rebars stubbed up. I asked the super if this is where I bond to the grid. He said no, bond to this 8 AWG thwn protruding through a 1 inch PVC stubbed up nearby.

I have two questions.

Was it necessary to beat down the ground rod I drove today? Would bonding to the # 8 have been sufficient?

Is a # 8 large enough to act as my GEC, for the grid?

The initial EC was fired. We inherited this job as a T & M project. The sub panel was supposed to be 100 amps, but the feeder wasn't large enough. I have already down-sized the breaker.

Where did this #8 come from?

 

[George Stolz]

Was it necessary to beat down the ground rod I drove today?

Not necessarily - if the rebar qualified as an electrode per 250.52(A)(3), then the ground rod would not have been necessary. A grounding electrode system could be considered required by 250.32(A).

If there was no CEE and the ground rod was 25 ohms to earth, then an additional ground rod would not be required.

Would bonding to the # 8 have been sufficient?

The #8 is there for different reasons, equipotential bonding. It should be connected to the remote pool equipment, to ensure no voltage difference between them.

Then there is an EGC between the equipment and the panelboard with the branch circuit conductors. The #8 doesn't go to the panelboard in this case, IMO.

Is a # 8 large enough to act as my GEC, for the grid?

No, not for the purposes of 250.32(A).

The initial EC was fired. We inherited this job as a T & M project. The sub panel was supposed to be 100 amps, but the feeder wasn't large enough. I have already down-sized the breaker.

...and the connected load is all right, right?

Edit: I removed my curveball comment, since Celtic had the same curveball in motion as I was posting. Looks like we're all equally clever about the detached structure aspect of this.

 

[sparky_magoo]

I have no idea where the # 8 came from. I don't trust it. I want to bond to the stubbed up rebars. I am running an emt over to the # 8 tomorrow. I wan't to talk the general into paying us to bond to the rebar as well.

I have never attached a stranded # 8 to rebar. I question this bond wire.

Landscapers ran all the underground conduit for the hot tub & landscape lighting. Every pipe run was full of mud, rocks, & water. I had to blow the mud out with a water hose. I would suck the water out with my vac. Blowing a mouse through every pipe was hard. My helper broke a # 12 stranded while tugging on the mule tape. It only had three other # 12's attached in a one inch pipe.

Landscapers should not run conduit.

 

[radiopet]

I installed a sub panel for a hot tub today. It is a Homeline 125A 12/24. It has a 60 amp main breaker. It is installed on a detached cinderblock wall. Th wall conceals the pool equiptment. It is a natuaral gas fired hot tub. The cinder block wall is L shaped. Inside of the L, I found some rebars stubbed up. I asked the super if this is where I bond to the grid. He said no, bond to this 8 AWG thwn protruding through a 1 inch PVC stubbed up nearby.

I have two questions.

Was it necessary to beat down the ground rod I drove today? Would bonding to the # 8 have been sufficient?

Is a # 8 large enough to act as my GEC, for the grid?

The initial EC was fired. We inherited this job as a T & M project. The sub panel was supposed to be 100 amps, but the feeder wasn't large enough. I have already down-sized the breaker.

I agree with Georges statement.....chances are this # 8 was part of the bonding grid for the hot tub area ( assuming you are under the 2005 NEC )...but being a "Remote Distribution Panel" that is detached chances are good you needed that ground rod ( unless you are playing by the 250.32(B)(2) allowances which may bring in other issues...sorry George I cleared that up a little better..)

Really would depend on the situation and the number of feeders they ran...BUT as George so well stated....chances are the # 8 had nothing to do with the grounding and probably can't be changed anyway now....so driving the rod was probably your best option since you kinda got DROPPED with the job.

I agree...I would run a new # 8 to the Rebar to be safe......yeah and GET paid for having to fix someone elses mistakes....indeed!

 

[suemarkp]

Why is #8 insufficient for the GEC? That is the smallest size in 250.66 and should be good for panel fed with #2. The poster didn't say what size wires were run, but with a 60A breaker I'm thinking #6.

I'm not so sure a Ufer is required if the concrete isn't 20' long. I'd just go with 2 ground rods and call it done. The #8 will have to be in conduit or you can use #6 if you protect it from damage. It my not hurt to run another GEC or bonding jumper to the rebar stubs in that wall, but again #8 is all you need for that GEC/jumper.

 

[George Stolz]

Paul, it makes it exceedingly hard to argue with you when you agree with me so often in a post.

...chances are good you needed that ground rod ( unless you are playing by the 250.32(B)(2) allowances )

How does 250.32(B)(2) change the need for a grounding electrode system?

I have no idea where the # 8 came from. I don't trust it.

Whoa, back the wagon up a sec - you have no idea where the other end is?

Equipotential bonding is required by 680.26 (by means of 680.42 in the case of a hot tub). That #8 should connect to a grid under paved surfaces around the tub. Are there any paved surfaces around the tub?

 

[sparky_magoo]

Actually, I was determined to drive a ground rod, reguardless of code. I always do this for pool sub panels, even if they are attached to the house. I was just curious what code wants. California is presently on the '02 code.

If I bond to the rebar, it will be # 4. Thats just how I do things. The exposed part will be "cool".

 

[Sierrasparky]

I was wondering if a seperate grounding electrode is required for a self contained spa tub sitting on a deck or concrete porch. Or is the ground is the #8 ground wire in used to ground the spa gfci sufficient

 

[George Stolz]

There are two different principles at play in the original post. There is a structure (the L-shaped wall) and there is pool equipment (the hot tub, and the remote pumps and heaters).

Equipotential Bonding
​

(Click on the small images to enlarge)​

Grounding of remote structure
​

Let's say we're dealing with a self-contained hot tub sitting on a concrete pad, with a single set of 120/240 single phase conductors supplying it.

The exception to 250.32(A) says that a single branch circuit supplying a structure does not require a GES. Therefore, if the conductors running into the tub are considered a branch circuit (not a feeder) then a GES is not required to be connected to.

A lot of hot tubs have little panelboards inside them - but if the panelboard is internal to the equipment (installed at the factory for the hot tub, inside the tub itself) then the conductors going into the equipment are branch circuit conductors. Otherwise, we'd have a 110.26 working space nightmare. The tub is listed as a complete unit.

So the #8 conductor connected to the rebar inside the concrete pad is not for grounding, it is for equipotential bonding. Getting back to your question:

I was wondering if a seperate grounding electrode is required for a self contained spa tub sitting on a deck or concrete porch. Or is the ground is the #8 ground wire in used to ground the spa gfci sufficient

Suppose that we were required to provide a GES for a hot tub. If the concrete pad complied with 250.52(A)(3), and the #8 were sufficient per 250.66, then I don't believe there is a prohibition from the equipotential bonding wire doing "double duty" as a GEC. But I think it would be a rare case.

All the above is just my opinion, and wide open for dissection.

 

[radiopet]

Err......George I was refering to the setup to the Remote Distribution Panel per se'...sorry I must have got side tracked....nothing removes the need for the Grounding System at that location.......no arguement there.

I was kinda asking in regards to " since it was dropped in his lap " and the wrong size conductors were run.....I was trying to see if they actually ran the proper number of conductors as well....and so on...

Sorry...I tend to jumble my sentences alot....

 

[sparky_magoo]

This is a large concrete hot tub dug into the ground. It will have two water falls flowing into it and it's gas heated.

 

[mpd]

was there any permits pulled for this? if there was the inspection office should have records of any inspections that were done