# Hot Tub Install--Grounding Rod Question



## Speedy Petey (Feb 1, 2004)

Sorry, but your dad is quite wrong. There is NO added "safety" in sinking a ground rod for a spa. In fact your friend is correct that if it is not bonded to the service EGC you can have problems.

Your father is under the common misconception that a ground rod serves any safety purpose at all. It does NOT. Especially when considering live wires and tripping breakers. 
Again, contrary to popular belief, power is NO seeking ground as many folks think. It is looking for it's source. 

Here is some good info:
http://www.mikeholt.com/technical.p...Does Not Assist in Clearing a Fault (01-25-2K)

http://www.mikeholt.com/technical.p...d Does Not Reduce Touch Potential (01-25-2K)


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## JohnTelcoMan (Sep 5, 2007)

Also if your spa has an underwater light you must run your conductors in conduit all the way to the main panel.

And yes installing a ground rod is a bad idea creates differnet potential.


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## Speedy Petey (Feb 1, 2004)

JohnTelcoMan said:


> Also if your spa has an underwater light you must run your conductors in conduit all the way to the main panel.


This is a controversial subject. To simply say _"if your spa has an underwater light you must run your conductors in conduit all the way to the main panel"_ is WAY too broad of a statement that does not apply in many/most cases. If you've ever seen the lights installed in a package spa you'd know why it does not apply. They are simply not what is referred to in that section of the code.
Usually it falls to the fact that the light is part of a "package" spa and does NOT follow the same rules that pools do in this regard. 
If the spa is "assembled" on site and is comprised of different parts, the light being one of them, then yes, it does have to follow the same rule as pools. 
Most every package spa I have done in recent years has had either a low voltage or fiber optic light so this "all conduit" rule does not apply.


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## JohnTelcoMan (Sep 5, 2007)

Speedy Petey said:


> This is a controversial subject. To simply say _"if your spa has an underwater light you must run your conductors in conduit all the way to the main panel"_ is WAY too broad of a statement that does not apply in many/most cases. If you've ever seen the lights installed in a package spa you'd know why it does not apply. They are simply not what is referred to in that section of the code.
> Usually it falls to the fact that the light is part of a "package" spa and does NOT follow the same rules that pools do in this regard.
> If the spa is "assembled" on site and is comprised of different parts, the light being one of them, then yes, it does have to follow the same rule as pools.
> Most every package spa I have done in recent years has had either a low voltage or fiber optic light so this "all conduit" rule does not apply.


 
Wow I really wish I knew that when I put mine in. Actually the whole low voltage thing Is what I was thinking about at that time. I think John N is the one who mentioned the whole conduit thing to me.


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## Speedy Petey (Feb 1, 2004)

Some AHJs are trying to enforce this rule applying it to package spas. 
IMO I don't know how they get away with it. If you look at the descriptions in 680.23 is is quite obvious that none apply to the average package spa. That whole section is aimed at underwater lights that require re-lamping from the water side. 

Even 680.42(C) specifically states _"Wiring to an underwater light shall comply with 680.23 *or* 680.33"_. 
How can the wiring "_to the light_" comply when it already done at the factory?
680.33 is the closest thing that would apply and it says nothing about conduit.


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## statgeek_rob (Sep 11, 2007)

*Thanks!!*

Wow--thanks for the speedy help folks! So I guess I pounded that 8' grounding rod into the earth for nothing then.... crap.

I'll head your advice on this one, but if you have just a moment, can someone explain to me why having two grounds is a potential problem? I'm just curious as to how that could be a problem? I guess I'm one of those people who likes to understand the "why" of it all...

Even if you don't have time to answer this new inquiry... thanks again for your advice!!


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## statgeek_rob (Sep 11, 2007)

*Follow-up question*

Folks;

Please endulge one more question on this topic?? :yes: 

If I connect the new grounding rod to the bar that's part of the new service box (that contains the GFCI), AND IF I ALSO connect that bar to my main panel's ground, then is there any problem?

My read of the material that Speedy Pety recommended, and to this thread suggested that there could be danger in an additional grounding rod that was NOT connected to my home panel, and its' respective grounding rod.

But if the two grounding rods (the original on 1 side of my home, and a new on on the other side of my home closer to the hot tub) are connected to one another via the 6ga ground wire that services the Spa Disconnect GFCI from the 60amp breaker in my main panel...Then don't the two grounding rods essentially behave as one? :confused1:


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## Speedy Petey (Feb 1, 2004)

Exactly. The added ground rod is perfectly fine, albeit superfluous, as long as it is bonded to the other grounding electrodes in the system.


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## statgeek_rob (Sep 11, 2007)

*Thanks!*

OK, Great! Thanks!!

My dad will be able to try out the hot tub w/o fear then, thanks!!

:thumbsup:


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## Stubbie (Jan 7, 2007)

Connecting the ground rod to the spa panel ground bar I don't believe would be acceptable since the spa panel is in the same structure as the service main panel. This would utilize the equipment ground of the spa feeder as the bond to the main service panels GEC. I don't believe code allows this. Personally I would just abandon the ground rod and not use it. If the feeder ground opened along with an event of a voltage gradient in the area of the spa (like a neighbors service neutral having a fault to earth) current may backfeed the ground rod and travel to the spa via the equipment ground. It would be much better to not have this possibilty however remote it may be. If you must have that ground rod to have peace of mind with your dad then do not bond it to the spa panel ground bar but run a bare #6 to the main services ground rod add a clamp to it and bond it there. My read of the GEC system is that in the same structure the grounding electrodes are to be bonded to each other and the service panel via a grounding electrode conductor not an equipment ground as you are suggesting.

Stubbie


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## Speedy Petey (Feb 1, 2004)

Actually stubbie is correct. I misread that post. 
You would have to use a dedicated GEC to bond the rods, not the EGC from the spa feed.


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## Stubbie (Jan 7, 2007)

Actually I read it the first time just as Speedy did and thought nothing of it... but the second time through I caught the fact you were going to the spa panel with the ground rod. The #6 ground you qouted is what threw me off. That is usually the gec size for the main panel and I thought you were running that to the main panel ground bar not the spa panel.

Stubbie


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## Speedy Petey (Feb 1, 2004)

Stubbie said:


> The #6 ground you qouted is what threw me off.


Yeah, that's what got me. I must have been using my man-vision.


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## statgeek_rob (Sep 11, 2007)

*Check this?*

Agian, my thanks for your focused advice!! Here's a copy of the instructions that came with the GFCI that was included in my Spa Disconnect:










And here is my drawing of how I planned on wiring this all up:










Are you saying that this plan is improper (dangerous)? I don't quite understand the part about "havingto use a dedicated GEC to bond the rods, not the EGC from the spa feed."

I don't follow the lingo here?? Is my plan alright now that you see the above pictures, or do I need to so something different??


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## Joba Fett (Aug 14, 2007)

Rob,..
1)The sketch is not correct. That ground rod at the spa poses a significant hazard if a voltage gradient were to be present.
1a)I sure hope you ran these conductors in rigid conduit or PVC, not direct burial UF cable or conductors in EMT.
2)You are getting licensed, experienced personnel to give YOU the CORRECT answers, not your dad. He does not need to, nor does he have the expertise, critique the responses.
3)One thing appears to be missing. The *#8 SOLID Cu* bonding conductor. This is probably the most important aspect of this project. All metallic components of the spa and the motor must be BONDED together in on *CONTINUOUS UNBROKEN* loop with the proper lug type fasteners.
4)I really suggest getting a permit from your local inspection authority, and while you are there....talk with him on the bonding/grounding aspect of this project...not your dad. He may mean well ... but he's wrong.
Good Luck .....


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## Stubbie (Jan 7, 2007)

Rob:

One question before I drown you with information....What kind of surface is the spa set on concrete...wood or other surface?

First I want to say that adding a ground rod to the spa panel is _not a_ _requirement_ and in my opinion will not add safety to the spa as your Dad seems to feel. *But* on further inquiry I was in error that it would be a code violation. There is a rather obscure code section that does allow the ground rod in a supplementary application as you are showing it in your diagram. I verified this as being acceptable on another professional forum *but* with several reservations from those electricians. The general argument for using a ground rod in the application you show in your diagram is Section 250.54 of the NEC, it permits a grounding electrode to be connected to an equipment grounding conductor, as described in 250.118. Essentially, this allows for localized earthing to hold the equipment ground to the same value as the local ground nearby that equipment. This "supplementary" ground rod is not considered part of the electrical service grounding electrode system.

But it is not to be considered a ground fault path to clear electrical faults causing the overcurrent device (circuit breaker) to open.

This is why your Dad is mistaken, fault current will not flow to the spa ground rod you show in your diagram from an electrical short in the spa equipment, it flows on the equipment ground ran with the branch circuit conductors and spa panel feeder back to the power source. 

So please read the below explanations to your questions.



> I don't quite understand the part about "having to use a dedicated GEC to bond the rods, not the EGC from the spa feed."


GEC.....Grounding Electrode Conductor.

EGC.....Equipment Grounding Conductor

The above acronyms are completely different systems... ground rods are part of the GES (grounding electrode system) in which all electrodes are connected to the main service panel and each other using a gec (grounding electrode conductor). This conductor is usually a #6 awg bare copper conductor. The GES is not a grounding (earthing) for the electrical system to provide safety from ground fault..... it is for property protection from a *high* *voltage* event like lightning or a huge power surge coming from the utility. It serves no benefit of human safety for your spa. 

The EGC (equipment ground) is for human safety and facilitates the bonding of metal parts to an effective ground fault path back to the center tap of the separately derived system (Transformer) to allow sufficient current to flow to trip a breaker. _Fault current does not flow to earth via the grounding electrode conductor to the ground rods. It flows back to the source. _The earth is is not a good enough conductor to allow current to flow with the necessary amps at normal residential voltages to get a circuit breaker to trip out. The ground electrode system (GES) is not the equipment ground system (EGC).





> Are you saying that this plan is improper (dangerous)?


No.... if done properly it is not a hazard but creates a catch 22 IMO. NEC 250.54 allows the ground rod connected to the spa panel ground bar as a supplementary electrode (as you show in your diagram) for voltage gradient control. A supplementary ground rod is not subject to the grounding electrode bonding requirements of the main panel GES. So long as you connect it to the egc at the spa panel with a minimun #8 solid copper bonding jumper. However, this is rarely done and is not a requirement. It sets up a possibility of a voltage gradient energizing your spa metal via the equipment ground if the *feeder* equipment ground would open or be disconnected. So it's sort of a trade off. IMO I would drive it below grade and not use it as I think the installation is safer without it. It is more important that the metal of the spa itself has the proper bonding as Jgarth mentioned. This bonding requirement may or may not require any action on your part. It is this bonding of metal parts that is the most beneficial in eliminating an unwanted voltage gradient.... the ground rod is redundant in that it just adds more metal to be bonded.
When you have equal potential created by bonding the metal parts of the spa then by definition you do not have a voltage difference. Without a voltage difference, there can be no current flow. So you use an equipotential bonding system — not a grounding system..ie (ground rods) — to reduce shock hazards. 

One of the myths about grounding (earthing) is that it reduces shock hazards by bringing everything to ground potential. Because the earth is not of uniform conductivity this will not be the desired result.

Some spas are self-contained in that all the spa equipment is inside the spa structure but the equipment is not on a common metal frame and therefore requires a 8 awg solid copper bonding conductor to be ran to all the metal parts.

Some spas are "packaged" in that all the equipment that runs the spa is mounted on a common metal frame and that frame serves as the bonding requirement so no further action by you is necessary.

OK...now to your diagram. First there are no positives just hot wires (ungrounded conductors) , neutrals, grounded legs, and equipment grounds.


As for the connections at the spa panel. See the diagram at the last of this post.. Your gfci doesn't have a ground wire .... it has a white *neutral* wire curly pigtail. It connects to the neutral bar of the spa panel not the ground bar. The neutral and equipment ground are separated at the spa panel. You may or may not have to carry the neutral to the spa control panel it just depends if the spa requires 120 volts along with 240 volts. The bottom right conduit shows the load side wiring going to the spa control panel.

I just can't cover eveything you need to know. So I'll just say that it is imperative that you have your spa inspected by the local codes department electrical inspectors to insure the safety of your family. They should also have a guide available for the requirements of a spa/hot tub install.

Some things you should read and credits for information provided.

http://www.mikeholt.com/files/PDF/Pooldownload.pdf

http://www.imsasafety.org/journal/novdec04/6.pdf

http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Grounding-versus-Bonding-Part-6-of-12~20050407.php


Stubbie


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