AG Pool wiring and other headaches

[denanbob]

Thanks Peter. I wonder why we shouldn't connect the bonding wire to the ground rods. Anyone know? We know 2 electricians and neither one of them knows anything about pool wiring. Maybe because not many people have pools in Ohio since it's always raining and cold in the summer and you can't swim anyway? Or is that only because we put a pool in that the weather is like that? LOL!

[matt4x4]

Grounding a pool is kinda funny, my instructions told me to put a ground rod in and ground the pool to it, so I did, and while I was bonding everything, it occured to me that through bonding everything to the pool structure, I have now automatically grounded everything too since I separately grounded the pool structure but it is all one.
Now, here's the reason you're not supposed to put a ground at the pool:
Your house allready has a ground rod to which ALL your electrical is grounded (including that line to the pool). BUT after speaking to an electrician friend of mine, he recommended that I do put a rod in at the pool as the instructions said BECAUSE the pool is so far removed from my house that the ground wire being several hundreds of feet long may well melt if my pool was hit by lightning, thus zapping everyone in it, having a ground rod close by with a heavy guage wire lead, the chances of melting the wire are greatly reduced. (it's a weakest link scenario). SOOOO, to make a long and complicated story short, he said that I'm essentially grounding to the same point anyways (the dirt on my property), and am really just insuring a secure and safe ground by putting a rod at the pool.
He stated that this should be done on every steel structure outside since teh ground wire in conduit does not handle huge amounts of current, any lightning strike can fry it even if the line is only 20 feet long, and that's really what you're protecting against, mother nature, the GFCI and bonding takes care of electrical issues that could shock you.
Hope this helps!

[denanbob]

That does help, thanks Matt! However, should I change anything about what we've done or just leave it alone and know it's probably overkill?

[matt4x4]

If you don't connect to the ground rod at the pool, you are STILL connected to the ground rod at the house, so is all yourt BONDED equipment since anything electrical like the motor casing/housing will be grounded allready, you're essentially grounding your bonding, EXCEPT you're doing it through a tiny wire that may not withstand a lightning strike (and that's the route a lightning strike would take).
In my opinion, you're safer with a ground rod or six or ten, like I stated before, anything electrical that goes wrong, your pool is tied to your pump, to your GFCI, to your Electrical Ground (which is also teh house ground for anything metal), so anything goes wron electrically speaking, you're safe, the GFCI will pop.
A scenario of why you'd need this is that if your DH would be mowing the lawn while you're in the pool and he accidentally mows over the pump cord, the cut/live end hits the pool, voila GFCI goes "pop" and you live. Electricity would trip the GFCI since it's wired to do so (whether or not you have a ground stake).

A scenario where the ground rods save you is when all electrical is OK, you're swimming (again! Is that ALL you do???), a rogue lightning stike hits the pool, the ground rods take care of it and you live (again! - what do you have, 9 lives or something??)
Oh, BTW - In this scenario, the GFCI may be fried, but hey, you got to live, so that's not a bad tradeoff.....then again, you may want to verify that statement with DH.

Since your pool is sitting on the ground, the second the ground is wet, you essentially have a ground rod anyways since water conducts electricity.
The reason they have you install RODS is so that there is always good continuity to ground - meaning, the rod penetrates the ground so far that the earth it's in is always wet or damp at minimum meaning it will ALWAYS conduct electricity.

So the question to you is - do you feel lucky?

[prh129]

Normally, you have a ground wire so that if there is a failure, the electricity has a path to ground that it goes to instead of going through you. If you have a ground wire tied to the pool and let's say the electric wire from the pump severed and touched the pool then electricity would flow through the pool to ground and if someone was in the pool then it would seem like they would be electrocuted. Without the ground wire, the pool would go up to the line voltage but no current would theoretically flow so someone in the pool shouldn't be harmed. This matches John T's explanation of the purpose of bonding. However, the bonding wire just sits on the ground so the pool is not totally isolated but I'm guessing the amount of current that can flow to ground is much less through a thinner wire sitting on the ground wire than a fat rod buried in the ground.

In either case if your pool was hit by lightning I think anyone in it would be toast.

If the above is true then I would remove the connections to ground.

Peter

[matt4x4]

If you're in your pool, and the severed cable hits the pool or the motor armature shorts or whatever, you DO NOT FRY, because EVERYTHING is BONDED back to the motor armature in a loop, including the ground post which ends up just becoming an extension of the pool wall or anything else metal that is bonded, it has NOTHING to do with GROUNDING in THIS particular scenario, the only time the rod is beneficial above and beyond being a metal stick in the ground is when lightning strikes....when lightning stikes, you don't need a bond, and the system now works as a lightning ground.
Remember that with or without a ground ROD, you still have a ground that is connected in the the exact same way, the only difference being it is a thin wire that runs back to the house, this wire cannot withstand the current produced by lightning, but is fine for any malfunction related to your equipment.
So, the only reason you're putting in a ground rod is to allow you to ALSO deal with safely dissipating the IMMENSE current produced by lightning which the little wire running back to the house is UNABLE to do for you. In my opinion, it's a pretty good reason to do so.....but hey, you only live once.

If Grounding your pool properly is a safety concern, then pumps and lights should not ship with ground wires, you would not have to run a grounded circuit to your pool, and last but not least you would have to build your pool on top of something like a rubber membrane or pink styrofoam that stretches beyond the reaches of the pool wall because the ground it's built on, the same ground the wall channels sit on is definitely not an insulator.

[denanbob]

You guys are going to kill me...........I think I'm following, but can you just answer this question:

Do we need to change the setup or is it fine? I can't tell if I'm going to die or not from the explanations. ROFL!

[prh129]

Denanbob - I don't have the expertise to tell you what to do here so I won't.

I was thinking about this some more and if the pump is double insulated then I don't believe that the bonding wire connects to the circuit ground back to the panel.

Anyway, if lightning hits an AG pool, it's made of metal and it's sitting on the ground so the lightning has a direct path to ground through the pool so it shouldn't need to flow through the ground wire back to the panel. I don't think a grounding rod would provide any more safety in the case of a lightning strike (or other situation). If it did then why wouldn't the electrical code (article 680) specifically call for it?

Peter