Can you run PVC for residential pool wiring for the pump motor and Pool light? I have always seen wrapped ridgid, unless you can convert to PVC once deep enough.
Also, why do they always use copper pipe to run to the pool light itself

Motor,Yes 680.21(A)(1) The branch circuits for pool associated motors can be installed in rmc,imc,rnc,or type mc, ect.
Lights,
Lights, "why do they always use copper?"
680.23(B)(2) Conduit shall be rigid metal,itermediate metal, liquid tight flexible nonmetallic, or rigid nonmetallic
(a) Metal Conduit. Metal shall be approved and shall be of brass or other approved corrosion-resistant metal
I suggest you read these articles as they are abreviated.

I haven't seen a pool wired in metal in 20 years. PVC with the 8ga ground wire seems to be the standard pool light setup. Be sure you "pot" the connection in the forming shell with a listed "goo" kit. That really just goes to the metal ring/shell on the light, since everything else is probably plastic too. The EGC is in the cord. It all gets bonded together in the listed J box, from there 8ga to the rest of the grid.

I agree Greg- I had one guy about 2 years ago install K Copper from the niche to the deck box and he was asked to change it.

I wish the code panel would decide what that #8 wire should be called. The've waffled back and forth between grounding and bonding over the last coupla cycles. I see in the '05 it's back to being a bonding conductor.

For the interest of those who don't routinely wire pools, the raceway from the niche to the deck box on an in ground pool, is the raceway that needs to be brass or PVC. Once your past the deck box you can run regular RMC or PVC underground.

I have yet to see a job where they use brass. Must be a cost factor.

Doesn't the 8 gauge bond wire have to be continuous from the panel to the pump motor and bonded to the brass pipe going to the pool light? Or can you just run the bond wire from the brass pipe to the pump motor. Considering there is a ground already run with the pump motor circuit, (plus the 15a pool light GFI circuit, which is separate of course).
On this job they are just moving the pool equipment to another location. So I'll probably dig up the brass pipe (for the light) and bend it over to the other spot. Then just rerun a new line to the pump motor and pool light circuit. They may be adding a heat pump for the spa which next to the pool, which I could run in the same pipe.

One other question is, I have to run from the panel then along the outside wall, then down to underground, then to the pool equipment.
In the past I've usually run EMT along a wall, then convert to wrapped ridgid to enter underground, then when deep enough convert to PVC.
I had an inspecter once say I could run PVC along a outside wall. So what if I just run EMT along the wall (would rather use EMT there), then convert to PVC when entering the ground, (not use the ridgid), and come up at the other end with PVC to the pool pump motor timer and light circuit. This would be code, correct?

As long as your EMT is properly bonded at the line end your plan is fine "where installed on buildings" 680.21(A)(2).
Your first question gets into the difference between the grounding and bonding conductors George was talking about. The 8ga is the equipotential 680.26 BONDING grid and that is not required to be connected to the ground bus in the panel. 680.26(A)FPN
The objective is simply to bond all of the metal that touches the water, and out from the deck 3' (2005) in a solidly connected grid. Those 8 ga wires can have "Connection shall be made by exothermic welding or by pressure connectors or clamps that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy." 680.26(C)
The conductor that must be made without joint or splice, is from the panel to the listed underwarer water "J" box (aka deck box, although they will be out in the yard, as often as not. The excewption to the "without joint or splice" is a busbar in the timer or listed switch enclosure. 680.23(F)(2)ex.
This is going to be a 12ga or larger insulated wire.
The pump also requires a 12ga or larger insulated equipment grounding conductor but the code is silent about splices. Some inspectors still like to see it unspliced. YMMV.

The whole issue about whether this is grounding or bonding and in fact whether the pool becomes a grounding electrode will usually start a fight in an inspector meeting. The fact still remains that the 680.23 "bonding" grid is electrically connected to the required "grounding" conductors at the pump, the light, the heater and the underwater speakers so the electrons will go where the EMF drives them.
I decided in my pool to just bond the spa grid, pool grid and panel GEC bus to a common copper bus with a #8 and stop making the distinction. I am grounded/bonded six ways from sunday. I am hoping, when the lightning hits, all of that juice finds it's way to ground as fast as possible.

gfretwell,
By bonding grid , you mean the rebar the pool is lined with, right? I would think the copper or brass pipe for the light would be bonded to that too.
As far as the motor bonding, I could just run the #12 from the motor housing to the motor timer, (which would have a continuous ground in it from the panel, plus the ground in the liquidtite to power up the motor). As an extra I could bond the brass pipe too, even though it is already grounded.

(Ridgid pipe - Don't know about you guys but I have seen so many WRAPPED ridgid pipes rusted out and would rather use PVC underground. They make the schedule 80 which is even thicker than the 40).
Do you agree that PVC is legal to run above the ground? It does say sunlight resistence on the PVC.
Hope all this makes sense,

Thanks for your help.

I have been doing electrical work for about 25 years now and I have only seen brass pipe to the wet niche light fixture once or twice. I am not sure if you can even get it anymore.

Maybe its different here in AZ because thats all I've seen, the brass/copper (whichever one it is) to the pool light.
I've got about 25 years too. The time sure went quick, didn't it? :-)

The #12s are GROUNDS, the #8s are BONDS ... not the same thing, you need both at the light, pump etc. There should be a lug on the pump for the #8 copper.
The "grid" is all of that stuff you BOND together with the #8s. That is pretty much anything metal near the pool or in the water circulation system. That includes your pool and deck steel, ladder cups, diving board stands, the metal pool cage if it is within 5' anywhere, window and door frames in that 5' envelope. In 2005 you are also extending a copper grid in the dirt, 3' out, if you don't have deck steel. If any of the rebar is epoxy coated you need to duplicate it with copper or some other acceptible method. (Say goodbye to coated rebar and pool pavers)
It is imp[ortant to understyand the function of the eqipotential bonding grid is not to ground anything, simply to assure everything is at the same voltage.
It incidentally gets connected to the groundiung electrode system by the equipment grounding conductors via the equipment.

Greg- Your last reply was probably one of the best if not the best capsule statment of wiring a pool/spa and addressing the bonding and grounding needs. If I can only remember it when I run my classes

You could say that. The last time I checked, 1/2" red brass conduit was about $6 a foot.

No wonder deck boxes always used to be flush-mounted, as close to the pool edge as possible.

Has anyone ever had any problems with stray voltage and pools? Or plastic/fiberglass pools and stray voltage?

Harold:
There was/is a situation of stray voltage around my neighborhood in Brick. It was in the Asbury Park Press a few times in fall.

Seems 'they' are saying it's JCP&L/GPU source due to 'single wire earth return' utility transmission system. I don't have a firm grip on it, but something about bare neutral, and grd rods at each pole, neutral 'undersized'; less resistance in/at rod & earth to the pools. One home had >24v at the pool, with the service disconnected.

I have not heard anything over the winter on this, and NO I don't have a pool!!!

John

That is the reason for the equipotential BONDING grid. Even if the pool was 24vac referenced to "something else", everything within 5 feet of the water would be 24v and you would be the bird on the wire. No current would flow through your body.

The more that gets included in your bonding grid, the bigger the safe area would be.

Large ground shifts between adjacent buildings are pretty common here in Florida anyway.

OK...Harold Endean...if the pool is fiberglass with no metal objects to bond, and there is stray voltage in the ground surrounding the pool, can the water in the pool be conductive enough to establish a path for the stray voltage to cause harm to persons using the pool?

shortcircuit

I have seen at least 2-3 problems where there was stray voltage in the area on someones brand new fiberglass pool. In the first instance, the EC asked me how he should bond the pool since there was no metal anywhere. I sad that if he ran a #8 bonding wire all around the pool, he would be safe in case they added anything metal to this pool. A year later I hear that there is about a 10 volt difference between the water and the cement patio around the pool. The EC not only checked the pool, but he checked a iron railing to the front door, a neighbors house, and other metal parts in the neighborhood. He was finding stray voltage everywhere. I am not involved with that town anymore so I don't know the outcome of this job.

Another EC wired a fiberglass pool and I asked him about stray voltage and he looked at me like I had 2 heads. About 2 weeks later I get a call from the EC asking me what he should do about the stray voltage. Long story-short, he installed about 20 ground rods all around the pool with exotermic welded connections and the problem went away. It seems a neighbors house must be having a problem. The reason I say that was because when the new rods where install on the neighbors side, the voltage went away.

I suppose this stray voltage on plastic pools is why they added 680.26(C).
You will be establishing a bonding grid in the dirt if there is no concrete or concrete pool deck rebar. If there is a concrete deck with rebar that should be part of your bonding grid, along with the pump and light so I am not sure why the water would be at a different potential. There is a TIA removing the requirement for a ground mat under a glass pool (the way it reads now) but that may come back if there is still a problem.

gfretwell, what I'm trying to understand is, if the fiberglass pool has nothing to bond (no light or metal objects) and the pools pump is double insulated without bonding, how can there be a potential differance between the stray voltage in the earth surrounding the pool and the water in the pool? I can't see a conductive path in this scenario.

Now...if the pool motor is bonded in the above fiberglass pool installation with no light or metal objects to bond, does the water in the pool create a path for the stray voltage to be harmful to a person useing the pool?

My answer would be no. I would think the resistance of the water would be too high and dangerous levels of current would not flow...?

shortcircuit

In some of the justifications I have seen for the ground mat under the fiberglass pool it was mentioned that they may be somewhat conductive. Although this is a very high resistance it still might be enough to get some stray voltage to the water across the thousands of square feet of material. With all the chjemicals in pool water I bet it is more conductive than you would think.
Some years ago I did some conductivity studies on water in a white bucket with 120v, 1 foot copper probes about a foot apart, a 60w light bulb and a meter. I don't remember all the details but I do know it didn't take many impurities (salt in my test) in the water to light the bulb. Maybe I will get a few minutes some day to do it again with pool water.

I did an experiment years ago, putting 2 ends of a wire in a glass of water and plugged in the other end.. and nothing happened. Not sure of the resistence of water but it does provide a much better path if your wet when getting shocked, because it coats your skin so well.

Could we NOT talk about doing electrical experiments with water? There might be some serious safety issues involved.

Thanks
Dave

I have to believe we are qualified professionals here who can manage the risks but if it needs to be said

"don't try this at home kids"

In the test bed I made before there were no exposed conductors and the bucket was closed up before the test was energized so the wet part was not exposed either. (GFCI present etc)

As for that one fiberglass pool, the one that the EC said he never heard of stray voltage, well he learned about it real quick. It seems he was wiring up the wet niche light and got wacked with voltage. I don't remember just how much, but the EC said that he felt it and he KNEW that the pool wasn't even wired yet. That was when I got the call for help with stray voltage. I think he was leaning over the coping working on the wet niche, plus the ground was wet.

Oh, I forgot, the stray voltage doesn't just happen to pools. A friend of mine who is an EC was wiring up a brand new house. The homeowner complained that when he touched the hose bib and he was barefoot, he got a shock. There was about 15-25 volts from the earth to the hose bib. The EC tried everything, he pulled the meter, the CATV, Telc. Water meter, but nothing worked. We think it was a bad underground wire from the POCO. The whole neighborhood was an UG development with pad mounted transformers.

Had an electrician call me to look at a new pool he was installing.
He said the GFI receptacle kept tripping.
Then he pointed out that the circuit hadn't been connected to the breaker.
Neighbor had a bad neutral that was back feeding to the pool grid.
There is stray voltage out there.
Alan--