Hot tub and ground rods

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maven

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What is the deal with driving ground rods at hot tubs? Is this a code requirement? I have seen two hot tubs lately that have been bonded to a ground rod.
I figured this was not necessary as long as all motors and equipment were bonded and the EGC bonded with the neutral at the first disconnecting means (usually the panel in the house).
Today, I asked a very well respected electrician with over 25 years of experience and he said to drive a ground rod at anything away from the structure that has the service for lightning protection such as a hot tub, generator, pool, shed, etc.
I really respect this guys opinion (I consider him a mentor/teacher), but for once, I think I disagree with him.
Can someone help me with this? Bottom line, I just don't want anyone getting hurt!
Thank you in advance!
 
Technically the code requires a grounding electrode system at a remote structure, so he's not totally off base. In order to have a compliant GES he would need to drive two ground rods though.

As long as there is a proper equipment ground then the ground rod is not a direct hazzard. Ground rods do nothing in terms of lightning protection, but being in a outdoor hot tub during a lightning storm is a bad idea with or without a ground rod.
 
ActionDave said:
Technically the code requires a grounding electrode system at a remote structure, so he's not totally off base. In order to have a compliant GES he would need to drive two ground rods though.

As long as there is a proper equipment ground then the ground rod is not a direct hazzard. Ground rods do nothing in terms of lightning protection, but being in a outdoor hot tub during a lightning storm is a bad idea with or without a ground rod.
Click to expand...

If there is a single circuit then no rod is needed. IMO, the hot tub requires one circuit which would fall under the following section's exception

250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.


Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non–current-carrying metal
parts of equipment.
Click to expand...
 
I agree no ground rod needed, but as far as a the single circuit, we hook some up that require multiple branch circuits. Usually a 30 amp 120/240, and a 20 amp 240.
 
cuba_pete said:
uhhh...that statement in an of itself isn't true. NFPA 780 (start at 4.13 Grounding Electrodes) lays this out pretty clearly, so I am not going to banter about it.
Click to expand...
A simple NEC required ground rod does nothing in terms of lightning protection. As a component of a lightning protection system was not in the scope of my comment.
 
Safety

Safety

maven said:
What is the deal with driving ground rods at hot tubs? Is this a code requirement? I have seen two hot tubs lately that have been bonded to a ground rod.
I figured this was not necessary as long as all motors and equipment were bonded and the EGC bonded with the neutral at the first disconnecting means (usually the panel in the house).
Today, I asked a very well respected electrician with over 25 years of experience and he said to drive a ground rod at anything away from the structure that has the service for lightning protection such as a hot tub, generator, pool, shed, etc.
I really respect this guys opinion (I consider him a mentor/teacher), but for once, I think I disagree with him.
Can someone help me with this? Bottom line, I just don't want anyone getting hurt!
Thank you in advance!
Click to expand...
Note: Ground Bonding of the hot tub metal/electrical equipment with GFCI circuit protection is the main concern.
 
(A) Grounded Systems.


(1) Electrical System Grounding. Electrical systems that are
grounded shall be connected to earth in a manner that will
limit the voltage imposed by lightning, line surges, or unintentional
contact with higher-voltage lines and that will stabilize
the voltage to earth during normal operation.

So the notion of a ground rod, as past of the electrical system grounding does play a role in the implied lightning scenario. However, due to the fact the ground rods being driven at "hot tubs" are more than likely being done so as an "Auxiliary" electrode (per 250.54) which if done properly [not connected to the grounded(neutral) conductor in anyway] as expressed in that section it would cause no harmful effects. We see this needless connection many times (as you all are well aware) at parking lot lighting. we can only hope that those that use this function understand that it has nothing to do with grounding the electrical systems and more so to dissipate overvoltages, such as from lightning events and/or static discharge on manufacturer specific equipment as we know it.

So clearly the required grounding electrodes differ in that sense from the non-required auxiliary electrode to which this mentor is expressing to be used at "hot tubs". Considering I sit on both CMP 5 and 17, which ironically deals with both of these areas of interest, I would never recommend a ground rod be driven at a hot tub, even if it was done so in compliance with section 250.54 and permitted if so chosen to do so.
 
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