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The Raddish
04-22-2006, 01:18 PM
My wife and I bought a house in August that came with a pool. I've posted about it a few times here. Needless to say, the previous owner was an idiot whose answer to everything was "Shock it!"

I was planning on replacing the liner next weekend, but have had to push that project back. I was crawling around under the deck today to see what I needed to do to the wiring, and it appears that I need to rip up everything the previous owner has done and start from scratch.

Following is my progress in general so far, and I'll follow up with my questions. To date, I have accomplished the following:
• I have almost completely rebuilt a portion of the deck (http://forums.slickdeals.net/showthread.php?sduid=5936&t=152939) where the previous owner had spans of 38" without joists. This was where the ladder was located.

• I have cut out the old liner, which I am regretting having done. The pool completely drained over the winter. There were multiple patches on the liner when we got the pool, and it has not been water tight since we bought the house.

I cut the liner out about 6" from the top of the pool so that I could leave the top rails in place for structural integrity. My intention was to get the sand fixed up this weekend and cover it with plastic so that I can put the liner in next weekend. However, we had a few bad storms and I collected about 4" of water last night, which I am siphoning out as I type this. However, now there are leaves and 'crud' in the sand that I will have to deal with. :mad: I also have a hole with rust in one spot of the wall I need to sand/repaint, and plug with some JB Weld.

• In inspecting the wiring, I found that the the pump was wired with UF-B that is buried about 4" in the ground. The old and defunct Aqualuminator was on the same circuit. The 14AWG pump wire was 'spliced' with electrical tape to some UF-B that went to a switch located about 18" off the ground on a 2x4 stake.

• The pool is not bonded at any location.
They are lucky they didn't kill themselves swimming in this mess.

My altered plan of attack:
• Rip out all wiring, all the way back to the electrical box by the house. Fortunately, I'm only about 20' from the house, so it won't be a HUGE deal to do this.

• The breakers are all GFI 15Amp, so I guess that saves me from having to install GFI outlets at the pool itself. I still have to replace the UF-B with the correct wiring in conduit for both the auxiliary outlet and the pump circuit.

• Bond the pool with 8AWG wire. Not sure of the best approach for this at the moment.

• Replace the pump wire with 12AWG rubber.

• Set the 4' x 3' fiberglass pad that I bought on which to place the pump and motor. It was easier than trying to pour a concrete pad in such a cramped space.
Once all that is done, I can tackle the interior of the pool with cleaning up and leveling out the sand and then replacing the liner.

My wiring job is pretty simple. I have three lights outside the deck area that are wired to a switch on the deck. They are all UF-B, and will likely remain that way. I'd have to dig up the deck to bury conduit for these lights. They have their own GFI circuit that they do not share with anything else.

The other two circuits are the auxiliary circuit which will have two outlets. One on the deck for utility purposes, the other under the deck near the pump for the new Aqualuminator that I bought.

The last circuit will be a dedicated pump circuit. The only problem I foresee with this is that I already bought a pump timer, but it does not have a twist-loc plug. It's just straight three-pronged 120V. It is 15Amp, though, and it weatherproof. I'm debating using it anyway instead of buying a new one.

I do intend to put a switch in line before the pump so that I can easily turn it on and off for backwashing, etc.

I guess the purpose of this post is to look for pointers, or to see if I'm heading in the right direction. I have a copy of the 2002 NEC as it pertains to pool wiring, but I don't have experience with pools, so I hope to draw on some of your experiences to help me on my plan of attack.

Any and all comments/criticisms are welcome. I'd like to do this project correctly.

CarlD
04-22-2006, 01:57 PM
I think I'd find a reliable electrician, especially to bond the pool--remember that bonding cable needs to be green and single core, not stranded cable.

I use 2x2 pavers under my pump and filter. Works just fine.

Otherwise, check your town codes on pool wiring. They are weirder than you think.

duraleigh
04-22-2006, 02:21 PM
Hey, Raddish,

It sounds like you've got a pretty good grip on electrical. "JohnT" posts here frequently and knows pool wiring and bonding extensively. You might consider sending him an email or PM if he doesn't chime in.

I'm pretty sure that bonding wire needs to be bare..........not green insulated.

There's a couple of other posters who "get it" on this complex bonding issue........you guessed it...I'm NOT one of them:( :(. I'm sure you'll connect with someone who can look over your shoulder a little.

Kudos on being willing to tear out someone else's crap. That's mentally tough to do but you know it's the right thing. Sounds like you'll have a nice setup.

You'll get lot's of help with your liner install and your pool chemistry on the forum when you get ready for it.:)

The Raddish
04-22-2006, 03:38 PM
Thanks for the replies.

There is NO CHANCE that I will hire an electrician. As an electrical engineer I know that I am fully capable of tackling this project on my own. I just want to make sure I do it right.

This is how I intend to wire the pump circuit.

http://img188.imageshack.us/img188/1569/pumpcircuit6mr.gif

JohnT
04-22-2006, 03:53 PM
The current requirement is for #8 wire or larger, insulated or uninsulated. It's pretty tough to get insulated wire through all the connections required on a metal wall pool. The code is usually interpreted as one bonding point on each panel section, so above grounds are usually done every bottom rail section. I like to see the uprights done as well.

My recommendation is to go to an electrical supply store for the bonding clamps, although you can probably get a better deal on the wire at a homecenter. The homecenter will never have enough clamps in stock. I like to use self drilling screws for convenience. Make sure everything metal within 5 feet of the pool or that touches or could touch the water is connected to this wire. Also the pump motor, any heaters, slide bases, metal fence, railings ladders etc.. No ground rod is required.

The code for pools was changed quite a bit in the 2005 NEC, and is going to be changed more in 2008. Mostly for clarification, although the changes for concrete pools were significant.

The Raddish
04-22-2006, 04:45 PM
You'll have to excuse my lack of knowledge on some of the pool terminology. When you say every bottom rail section, I have 17 panels, so that is seventeen connections, right? Also, when you say you like to see the uprights done as well, you mean all 18 of them? I'd like to make this as safe as possible, but all 18 isn't feasible for more. Some I will not be able to get to because of the way the deck fits against about a quarter of the pool. There is enough room for a small child to crawl around down there, but not enough for even a teenager, let alone a full grown adult.

I can't say that I see myself tearing down the deck to do this.

When attaching the ground clamps, I'm assuming that two series strands will be fine, going each way around the pool and connecting at the outlet box as in my schematic, correct?

Where on the rail is the best way to attach the lugs? I don't want to weaken the rail or push against the side panel in any way.

By any chance, do you have any pictures of some attachment points that you could post?

Also, the run from the circuit breaker to the outlet box, what kind of wire do you recommend? Would MC be alright to take from the breaker panel to the pump outlet box? Could I use one MC cable for both the pump and axillary outlet circuit (obviously keeping the circuits separate)?

b2001
04-22-2006, 06:04 PM
I'd have to dig up the deck to bury conduit for these lights.

My apologies if I'm missing something here, but at least in my area - code is to bury cable and conduit 18 inches deep out in the open but conduit and cable can lay on top of the ground under a deck ...

The Raddish
04-22-2006, 06:21 PM
A large portion of the deck is about 20x20, just above ground level. The three exterior lights are on three sides of the deck with the pool and higher levels of the deck on the fourth side.

I just got in from yanking up the old UF-B cables a few minutes ago. I was mistaken about the orientation earlier.

I have four circuits, each on a 15A GFI breaker.

1). Pool pump.
2). Auqaluminator.
3). Axillary outlet available from on the deck, about 12' from the pool.
4). Circuit for the three exterior lights, which are all more than 15' away from the pool anyway.

Also, I did find that there is a grounding rod at the circuit breaker near the house, so the wiring is not quite as bad as I thought. It was buried in some ground cover and I missed it when looking for it previously, but since I cut some of the ground cover away while digging up the UF-B, I came across it.

The UF-B was just below the surface of the grass, maybe two or three inches at most. I'm starting to dig the trench tonight. It's only a run of just over 16', so I should get it dug by tomorrow.

CarlD
04-22-2006, 09:58 PM
Code in my town allows insulated bonding--but the insulation must be green.

Only reason I suggested an electrician is they need to know code to get licensed. If you know the codes, you don't need them.

JohnT
04-23-2006, 10:51 PM
You'll have to excuse my lack of knowledge on some of the pool terminology. When you say every bottom rail section, I have 17 panels, so that is seventeen connections, right? Also, when you say you like to see the uprights done as well, you mean all 18 of them? I'd like to make this as safe as possible, but all 18 isn't feasible for more.

It really depends on the construction of the pool. There is really no standard interpretation of code for bonding the metal walls. Usually, if the parts are connected metal-to-metal with screws or bolts, that is considered one piece. Some inspectors may disagree. The more that is bonded, the less you are depending on these non-electrical connections to perform as electrical connections.


When attaching the ground clamps, I'm assuming that two series strands will be fine, going each way around the pool and connecting at the outlet box as in my schematic, correct?

Your schematic shows a ground point on the bonding circuit. Not needed, and could potentially introduce problems. You are establishing an equipotential plane, where everything that a swimmer might contact is at the same voltage. It doesn't matter what that voltage might be, as long as it's the same everywhere. When you bond the pump motor, you will be connecting via the motor housing to the house ground. Adding that second ground point could be a problem. The best way to wire the bonding circuit is one continuous piece of wire, with the end tucked back into the first clamp on the pool. Buried splices are more difficult to handle, and the clamps are easy to feed wire through when the screw is loose.



Where on the rail is the best way to attach the lugs? I don't want to weaken the rail or push against the side panel in any way.

By any chance, do you have any pictures of some attachment points that you could post?

No pictures, sorry. Where to attach is a case-by-case deal. Sometimes it's obvious, sometimes not. Retrofitting would be harder. Anyplace that gets to each section is better than nothing, IMO.


Also, the run from the circuit breaker to the outlet box, what kind of wire do you recommend? Would MC be alright to take from the breaker panel to the pump outlet box? Could I use one MC cable for both the pump and axillary outlet circuit (obviously keeping the circuits separate)?

I won't play electrician on the power side and give advice. I will say don't splice grounds going to the pool area to reduce the likelihood of a failure. My background is that I am an electrical engineer who has a neighbor who is an electrician. He got into a mess with an inspector over code, and I mediated the whole mess, as niether one of them knew what was right. Now they both call me for help on Article 680. At least the neighbor brings beer:) . Most electricians don't understand 680, and worse, won't admit it.

The Raddish
04-24-2006, 01:11 AM
I really appreciate your input, JohnT. Between you and 680, I think I mostly have everything figured out.

Yesterday I dug up the old UF-B and started digging my trench to the pump. Today, I completely ripped out the old wiring with the exception of the auxiliary outlet and the area lighting circuit (which turned out to be on the same circuit after all). I also started fabricating the conduit in large pieces, and tomorrow I'll complete the wiring and conduit, with the exception of the bonding which I'll finish up during the week, weather permitting.

What I have done is put in 3/4" conduit from the breaker box to a T-junction under the deck. The conduit is buried about 14" or so, which is deeper than the 12" required by 680. Since I have GFI outlets at the breaker I didn't have to go 18". Out of each end of the T-junction I have reduced down to 1/2" conduit.

Out of one end of the T-junction will be the Aqualuminator branch circuit, wired with 12AWG THHN to a simplex outlet. It's a straight run without any breaks. The outlet is about 12' away from the edge of the pool, about 4' off the ground.

Out of the other end of the T-junction are both the pump circuit and the auxiliary outlet/area lighting circuit. The axillary outlet is also 12AWG THHN, and the pump I went with 10AWG THHN. The 10AWG is probably overkill, but it wasn't much more expensive than 12AWG, so I figured I'd step it up a bit.

Both circuits terminate at the pump outlet box, which is 8' from the edge of the pool and about 24" off the ground. Technically, this outlet should be a twist-lock but my timer is not twist lock and I'm not buying a new one at this point. If/when the timer goes out, I'll replace the simplex with a twist-lock simplex outlet later. I also have a switch for the pump run out of this box to a closer location on the deck for easy access to shut down the pump circuit.

In the same junction box as the pump simplex (but not connected to the pump circuit) is the axillary outlet circuit, which I am changing over to the existing UF-B that is already run to the axillary outlet and the area lights. The axillary outlet itself is just over 10' from the edge of the pool and the lights are all much further than that, so UF-B is legal to use for it according to 680.

I am not installing an earth ground at the pump simplex outlet as shown in my schematic. I am instead bonding about a dozen points on the pool itself to the pump housing. I'll stop by a pool supply store this week to ask about the best places for this, hopefully using some of the pools they have on site as an example.

If anyone is interested, I'll draw up another schematic later to show the final product and post it here. I'll also post some pics of various parts when my wife brings our digital camera back from her business trip in a couple weeks.

Again, thanks to everyone for their input on this thread. It was greatly appreciated.

matt4x4
04-24-2006, 11:11 AM
Wow, after reading all that, it gives even more reason to buying resin pools - I only had to bond my wall!
Sounds like you're on track with everything, Hope you're swimming soon after all that work!

NWMNMom
04-24-2006, 12:53 PM
Can someone explain "bonding" and some of the wiring requirements, why that is all needed? We are getting an AG pool and have a GFI panel close by (20') so expect to plug in right to that. Are these pump/filter set ups supposed to be hard wired? We don't plan on pool lights - our merc vapor yard light is right next to the pool area.

JohnT
04-24-2006, 02:06 PM
Can someone explain "bonding" and some of the wiring requirements, why that is all needed? We are getting an AG pool and have a GFI panel close by (20') so expect to plug in right to that. Are these pump/filter set ups supposed to be hard wired? We don't plan on pool lights - our merc vapor yard light is right next to the pool area.

Bonding is a wiring scheme that connects everything conductive associated with and near the pool so that it all remains at the same voltage if some electrical mishap occurs. You can only be shocked if you touch two things that are at different voltages, like the ground and a power line. Even if an electrical appliance fell into a properly bonded pool and the GFCI didn't trip, you wouldn't be shocked because everything you could touch would be the same voltage. (Any volunteers to prove it:p ) Bonding has nothing to do with the power system.

AG pumps are normally required to have twist-lock connectors, and the 20 ft won't meet code in some areas.

As to the light, if you want a pool full of bugs, you've found the answer. 15 years ago when we installed our first AG, it was about 30 ft from an outside light. It was bug city every morning. The best solution to lighting I've found is the citronella torches. Much more pleasant than anything electrical.

prh129
04-24-2006, 02:55 PM
NWMNMom,

Have you checked with your local building inspector to see if permits are required? I had to get a permit for the pool itself and I had to have a licensed electrician pull a permit for wiring the electrical connection to the pump.

The pumps typically come with a 3' cord so if your panel is 20', you will need to install an outlet closer to the pump. The electrical code limits a "flexible cord" to 3' so you aren't allowed to use an extension cord.

"Bonding" ties all of the metal parts of the pool structure together so that they are all at the same voltage. If you look up in the National Electrical Code, Article 680 talks about the requirements for a pool and that's what this discussion has been referring to.

Peter

prh129
04-24-2006, 03:02 PM
[QUOTE=The Raddish]
What I have done is put in 3/4" conduit from the breaker box to a T-junction under the deck. The conduit is buried about 14" or so, which is deeper than the 12" required by 680.
QUOTE]

Is this an older version of 680? I'm looking at the 2005 version and it states 18" for nonmetallic raceways.

I too only went about 14" down because my ground is loaded with rocks so I don't know if it will fly or not.

Sorry about the duplicate response on bonding - I didn't see John Ts answer while I was writing mine.

Peter

NWMNMom
04-24-2006, 03:10 PM
Ok, thanks for the answers. A couple of things:

1) we can't move the pool anywhere else (but didn't have problems with bugs in our 18' round, so fingers crossed, we won't when putting this one in the same spot)
2) we live 10 miles from the nearest town (if you can call it that - 20 miles from one that has anything nearing govening bodies that give permits) so permits are not an issue
3) if a new panel is required closer we will put one in
4) Ok, I'll talk to him about bonding too

Thanks!

The Raddish
04-24-2006, 03:46 PM
Is this an older version of 680? I'm looking at the 2005 version and it states 18" for nonmetallic raceways.
This is true if the breakers are not GFI. That aspect seems to make the difference. If your circuits are all GFI at the breaker box, then 12" is the required depth for nonmetallic raceways. If they are not GFI at the breaker box, then 18" is required.

At least, that is my understanding of the code. http://img.slickdeals.net/images/smilies2/i%20don't%20know.gif

prh129
04-24-2006, 04:55 PM
This is true if the breakers are not GFI. That aspect seems to make the difference. If your circuits are all GFI at the breaker box, then 12" is the required depth for nonmetallic raceways. If they are not GFI at the breaker box, then 18" is required.

At least, that is my understanding of the code. http://img.slickdeals.net/images/smilies2/i%20don't%20know.gif

OK - I see where that is defined in section 300.5. I will have a GFI breaker on the circuit so I would be covered in that case with a 12" depth but I'm not sure it meets with part 680.10.

It is not clear to me if the depths listed in 680.10 apply only to non-pool wiring that can't be moved away from the pool area or if it's for all wiring in the pool area. I'd like to know up front in case it becomes an issue at inspection time.

John T - you seem to have experience with this - what do you know about this?

Thanks

Peter

The Raddish
04-24-2006, 09:59 PM
...any tricks?

I'm pulling three 10AWG and six 12AWG wires through about 30 feet of 3/4" nonmetallic conduit with two 90º standard radius turns.

I do have string strung through the conduit, so I can tie it off if needed.

rbutera
04-24-2006, 11:10 PM
Not sure this was brought up before (I came in late), but I wired up my pool 4 years ago and spent a lot of time sorting out the codes.

One issue that has not been mentioned: if your pool pump is double insulated (most likely is), the bonding wire should not be attached to it.

(Yet the 2002 code says you should still keep in nearby just in case some day someone else installs a non-insulated pump ...)

I found the following web site useful:

http://www.selfhelpandmore.com/homewiringusa/2002/accessory/poolabove/index.htm

And confirmed most of it myself with the 2002 NEC (I'm a EE PE, though I don't use the PE much for a living -- sorting out the pool stuff is the most code-intensive thing I've done)

Another issue regarding pool lighting:

The code for underwater lighting is really specific. Like requiring that conduit is run all the way to the box (not just the house), and that the circuit is not shared with anything else except pool lighting. It is by far the most underutilized 15A circuit in my entire house (just one AG pool light).

JohnT
04-25-2006, 10:11 AM
OK - I see where that is defined in section 300.5. I will have a GFI breaker on the circuit so I would be covered in that case with a 12" depth but I'm not sure it meets with part 680.10.

It is not clear to me if the depths listed in 680.10 apply only to non-pool wiring that can't be moved away from the pool area or if it's for all wiring in the pool area. I'd like to know up front in case it becomes an issue at inspection time.

John T - you seem to have experience with this - what do you know about this?

Thanks

Peter

Peter, the first thing you need to be aware of is that local codes are often more strict than NEC, and sometimes have pretty unexpected requirements. Often, cities have a handout that outlines local codes. Also be aware that there are changes regarding pools in every revision of the NEC, and 2005 had many. These changes are mostly clarifications, because this stuff is confusing, and many electricians and inspectors don't understand it. Even if you are NEC 2005 to the letter, you may not be in compliance with local codes.

680 says no wiring with 5ft of the inside of the pool wall except for pool equipment feeds unless space or property lines make it necessary. For pool equipment wiring, 6 inches is the required depth for metal conduit, and 18 inches for non-metallic conduit. 680 does not make the exception for GFI. Although your 12 inch depth may meet article 300, it is in violation of 680.

It is my understanding that this requirement applies to all wiring in the pool area, even if it is not pool related and allowed by the space exception. Also, utility companies do not conform to NEC, but rather have their own code (NESC). If this affects you, contact your power company.

In a comment above, another poster stated that you shouldn't bond a double insulated pump motor. Per NEC 2005, the bonding wire must be installed, just not connected to the motor in the event a replacement motor is installed that requires bonding. These are primarily above ground pumps.

prh129
04-25-2006, 11:46 AM
Thanks John. I dug the trench and buried the conduit last fall so I could plant grass. The electrician is pulling the permit, installing the bonding wire and making all of the connections so the only thing I have to worry about is the conduit depth. At worst case, I'll just have to dig it up and bury it a little deeper (and hope I don't hit any huge rocks).

Peter

Mike_in_NJ
04-25-2006, 12:04 PM
Raddish,

Regarding pulling your wire through the conduit, three things come to mind right away:

- 1: I don't have a "fill table" handy, but I think you -might- have too many wires in that 3/4 conduit. Double check the allowable fill for conduit.

-2: Instead of standard elbows on the conduit, you can/should use pulling elbows. It also -might- be required to use pulling elbows. Again, I don't have the tables/code handy to look it up.

- 3: Use wire pulling lube aka "snot".

The Raddish
04-25-2006, 02:35 PM
For pool equipment wiring, 6 inches is the required depth for metal conduit, and 18 inches for non-metallic conduit. 680 does not make the exception for GFI. Although your 12 inch depth may meet article 300, it is in violation of 680.
While I don't currently have it in front of me, I could have sworn that I read something to this effect in 680:
"The nonmetallic conduit must be buried a minimum of 12” deep if 120 volt GFI protected from the start of the branch circuit. All nonmetallic conduit must be at least 18” deep, if not GFI protected."
In fact, this site (http://www.selfhelpandmore.com/homewiringusa/2002/accessory/poolabove/index.htm) has been pretty helpful in understanding the NEC section 680, and he points out this burial depth two or three times.

Either way, the conduit is all in place now, I need only wire the circuit at this point. I'm also not worried about passing any kind of inspection (since I'm out in the county and it is a previously installed pool, I don't need a permit), I'm mainly concerned with safety for me and my family. The previous wiring job was a death trap, literally. What I have replaced it with may not be 100% to code, but it is safe, and that's the important thing to me.


In a comment above, another poster stated that you shouldn't bond a double insulated pump motor. Per NEC 2005, the bonding wire must be installed, just not connected to the motor in the event a replacement motor is installed that requires bonding. These are primarily above ground pumps.
I saw that, and it got me to wondering: where would be the bonding point on this circuit, if not on the pump motor housing?


- 1: I don't have a "fill table" handy, but I think you -might- have too many wires in that 3/4 conduit. Double check the allowable fill for conduit.

-2: Instead of standard elbows on the conduit, you can/should use pulling elbows. It also -might- be required to use pulling elbows. Again, I don't have the tables/code handy to look it up.

- 3: Use wire pulling lube aka "snot".
1- I'm under 40% fill. I don't have the numbers here, but I'm fine.

2- Conduit is already assembled and buried at this point. Since I've only got two 90º standard radius turns, I should be okay. Last night I tried taping the wires together and pulling/pushing them through, but I made the mistake of not staggering the wires when I taped them.

I'll pick up some lube today or tomorrow and try again, this time with a few changes. One, I'll stagger the wires to make negotiating the bends in the conduit easier, and two, I'll use some heavier nylon cord instead of the thin twine that I was trying to use last night (which was getting me nowhere). The lube should help, too.

Again, thanks everyone for your input in this thread. Not only has it helped me, but I'm sure it has helped more than a couple of lurkers out there, too.

JohnT
04-25-2006, 03:23 PM
I saw that, and it got me to wondering: where would be the bonding point on this circuit, if not on the pump motor housing?

There is no bonding point. You just tie everything together. No ground is used, so the grounding that occurs via the pump motor housing is incidental.

The Raddish
04-25-2006, 04:08 PM
Okay, I think I have been getting bonding and grounding confused.

My pump will be located about eight feet from the pool. Everything that is bonded is supposed to be within five feet of the pool. The only metallic body greater than 4" square within five feet of my pool is the pool itself. Does this mean that bonding isn't necessary, unless I am to bond the different metal parts of the pool to itself? I also understand that the 8AWG wire should be run to the area of the pool pump in case a non-double insulated pump is every installed.

Also, I keep reading that an earth ground rod is not desirable on a pool circuit, and I am baffled as to why that is the case. This seems to imply that any grounding that takes place is to do so through the residence grounding system. Is this correct?

JohnT
04-25-2006, 04:54 PM
Okay, I think I have been getting bonding and grounding confused.

You are not alone:). Most electricians and pool installers don't get it either.



My pump will be located about eight feet from the pool. Everything that is bonded is supposed to be within five feet of the pool. The only metallic body greater than 4" square within five feet of my pool is the pool itself. Does this mean that bonding isn't necessary, unless I am to bond the different metal parts of the pool to itself?

That is exactly what you do: bond all of the metal pieces together so none can be at a different voltage. You also have to bond any conductive part of electrical equipment that could or does contact the pool water even if not within 5 feet. That would be some pump motors, heaters, SWCs etc..


Also, I keep reading that an earth ground rod is not desirable on a pool circuit, and I am baffled as to why that is the case. This seems to imply that any grounding that takes place is to do so through the residence grounding system. Is this correct?

By pool circuit, do you mean the power circuit for the pool? If so, it is bad practice to ground an electrical system at more than one point. You wind up with current flowing through the earth. Voltage is different at different points, so if you tie them together with a ground system, weird things happen. If you mean the bonding system, the idea is to create that "equipotential plane" which means anything the swimmer can touch is at one voltage. It doesn't matter if that voltage is the same as your house power, because any voltage without a reference is just an arbitrary number. If there is one thing conductive that a swimmer can touch that is at a different potential, then they can be shocked. Grounding just doesn't enter the equation. Adding a ground rod can make the whole mess subject to stray voltage problems. There was a FPN (Fine Print Note) added to the 2005 Code stating "equipotential stray voltage bonding conductors aren't required to extend to any panelboard, service equipment, or an electrode."

You really need to refer to the 2005 NEC. It explains some of this much more clearly than 2002. You may also want to Google for 2008 proposals for 680, as there is more change coming.

Look at Table 680.10 for burial depths. Clearly 18" min inside the 5 foot area.

The Raddish
04-25-2006, 06:55 PM
By pool circuit, do you mean the power circuit for the pool? If so, it is bad practice to ground an electrical system at more than one point. You wind up with current flowing through the earth.
As an EE, I understand ground loops. During this whole process I've been trying to bring my EE knowledge with me. I'm not an electrician, but I have done more than a few wiring projects at home. This is the first time I've ever been confused, and I think it is more terminology than anything. Your explanation of bonding in your above post i think cleared up the muddied waters for me.

Getting back to the grounding rod issue, is a grounding rod required at the breaker box for the pool (which is a separate box from the house, but fed from the house box)? I had to return the copy of the 2002 NEC that I had borrowed from a friend, so I don't have access to it any more. I seem to have read conflicting info on the grounding rod for the pool breaker box.


Look at Table 680.10 for burial depths. Clearly 18" min inside the 5 foot area.All of my underground conduit is greater than 10' away from the edge of the pool. It is nonmetallic, buried at about 14". Everything closer is above ground, attached to the deck structural members.

robot9000
06-04-2006, 12:55 PM
There is no bonding point. You just tie everything together. No ground is used, so the grounding that occurs via the pump motor housing is incidental.

Hi All, I'm in the beginning stages of building my AG pool. I too was a bit confused about the bonding thing. I think eveyone thinks of 'ground' as the magic bullet. "Here's your problem - you didn't ground it !" :D

Really, you are just tying everything the swimmer might touch that is metal to be at the same potential, which brings me to my comment/question.

I have no metal fence or anything within 15 ft of my pool. My pump is double insulated, so I really just need to bond the uprights/foot plates with the proper wire and have it long enough to reach my pump in case it was replaced with one not double insulated. Is that correct in a nutshell? No attaching it to a ground rod. No attaching it to the pump ckt ground. Just make use all the pool parts and anything metal around the pool is electrically connected.

Also, in my city, the code is for metal conduit to be at least 6in and non metal conduit to be at least 18 in buried.
Thanks !!

JohnT
06-04-2006, 04:38 PM
I really just need to bond the uprights/foot plates with the proper wire and have it long enough to reach my pump in case it was replaced with one not double insulated. Is that correct in a nutshell? No attaching it to a ground rod. No attaching it to the pump ckt ground. Just make use all the pool parts and anything metal around the pool is electrically connected.



Yes, that is correct.

haze_1956
06-05-2006, 09:06 AM
I thought I was following this but those last few posts got me reconfused.

Is this right ?

Bonding - Connecting a number of metal objects so they will have a common electrical potential, but not to be grounded.

If this is correct, wouldn't the metal housing of a double insulated pump still have to be bonded, if within a set distance from pool?

JohnT
06-05-2006, 09:52 AM
I thought I was following this but those last few posts got me reconfused.

Is this right ?

Bonding - Connecting a number of metal objects so they will have a common electrical potential, but not to be grounded.

If this is correct, wouldn't the metal housing of a double insulated pump still have to be bonded, if within a set distance from pool?

Double insulated pump motors are specifically exempted from bonding in the NEC. In order for a pump to be labelled "double-insulated", it must be tested and evaluated for this when it is tested by UL or other certifying organization. Small items are generally considered exempt from bonding requirements if it is unlikely they could become energized.

denanbob
07-02-2006, 06:09 PM
My DH just got done sledgehammering 10ft copper rods into the ground at six different points around our pool. I don't even know HOW we would begin to get those out. We searching for how to ground a pool and this is what we found. Now I'm finding out this may not be the case. He also put little copper connectors at the base of each of our posts/pillars that hold the pool up. He then is threading #6 copper wire through each connector and ground all the way around the pool. So it will go connector/ground rod/connector/ground rod, etc................Please tell me we don't have to rip this all out. If anything, is it just overkill?

denanbob
07-04-2006, 08:13 PM
Any comments on our grounding scenario? Good OR bad? Or do I not even want to know? LOL!

prh129
07-05-2006, 12:17 PM
I am not an electrician but from the information in JohnT's posts, the purpose of bonding is to tie all of the metal parts around the pool together but NOT connect them to ground so you can leave the 10 ft copper rods in the ground but don't connect the bonding wire to them. Only connect the bonding wire to the pool and the pump motor housing.

Peter

denanbob
07-05-2006, 01:14 PM
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
07-05-2006, 01:43 PM
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
07-05-2006, 03:03 PM
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
07-05-2006, 03:38 PM
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
07-05-2006, 03:45 PM
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
07-05-2006, 04:12 PM
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
07-05-2006, 05:06 PM
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
07-05-2006, 08:59 PM
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

matt4x4
07-06-2006, 09:15 AM
I would ground the pool to the rods, reason being, if lightning ever does strike and you do NOT have rods, under certain scenarios, it is not grounded well enough just by sitting on the "ground" (meaning dirt). if the "ground" is not wet enough, lightning will not travel into it, it's the moisture content in the "ground" that allows it to act as a grounding point, the dirt itself does pretty much nothing, the rods ensure that you are always grounding through soil that has moisture content, so essentially they are just an extension of all your pool metal into permanently wet/damp "ground".
Without the rods, If lightning strikes during a dry spell, the path of least resistance would be through the circuit ground wire (the thin one) back to the panel and into the grounding rod located at the house, however, this path would only be available to the lightning for a mili second because that's all it would take to burn up the wire, at that point you would no longer have a path to ground - therefore, to be absolutely safe, I would use the ground rods.

Grounding your pool through ground rods has absolutely NO effect on the bonding aspect of the pool, bonding is a completely different procedure meant for a completely different scenario, but still brings everything back to a ground rod at your house.
Bonding anything metal is done to ensure that if this metal becomes energized, it is safely taken to ground, eliminating any electrical potential within that item. However, bonding is not done for lightning strikes, it is done for electrical malfuntions where the current is much lower and will not cook your #12 wires. Metal things INSIDE your house will likely NEVER get struck by lightning, metal things outside of your house are always at risk, I looked at my Natural Gas tank located outside my house last night, I found a #8 wire leading directly to ground from the tank's body. I looked at my Electrical meter outside my house, another #8 directly to the house ground rod. When I installed my Satellite dish, it was not just recommended, it was specified to ground it within a certain number of feet otherwise the warranty would be null and void.
My pool instructions specified it as well, yes, it's not electrical code, but the pool manufacturer has nothing monetary to gain from this recommendation, yet they still recommend you do it.

BTW - Anything bonded within your house like plumbing, gas lines etc., goes DIRECTLY to the house ground rod through a minimum #8 wire, why would it be such a bad thing to do the same at the pool instead of relying on a thin #12 wire to bring it all the way back to the house just to let the #8 located there bring it to the ground rod?
The code specifies that a ground rod is NOT required, however, that does not mean you cannot install one, codes are MINIMUM giudelines you have to follow, however, like anything, going above and beyond the call of duty is not a bad thing.
I live in Canada, our electrical codes are different, usually our construction codes are stricter that those in the USA, I have not had time to look up our electrical codes on this issue, but this is going to make me do so as soon as i can, I WILL post back with my findings on that.

denanbob
07-06-2006, 09:46 AM
My DH just got done sledgehammering 10ft copper rods into the ground at six different points around our pool. I don't even know HOW we would begin to get those out. We searching for how to ground a pool and this is what we found. Now I'm finding out this may not be the case. He also put little copper connectors at the base of each of our posts/pillars that hold the pool up. He then is threading #6 copper wire through each connector and ground all the way around the pool. So it will go connector/ground rod/connector/ground rod, etc................Please tell me we don't have to rip this all out. If anything, is it just overkill?

Matt - so you're saying we're just fine with what we've done even though it's not required by code, right? Thanks sooooooooo much for the great explanations. I appreciate you taking the time to type all that out.

prh129
07-06-2006, 01:00 PM
I would be interested in getting JohnT's take on this as he seems to have a lot of experience with this.

Although #8 is heavier than #12, I'm not convinced that it too would not be able to handle the current from a lightning hit. Lightning rods use #4 so I suspect that the pool bonding connections do not take lightning into consideration.

In an earlier post, JohnT talked about not grounding a circuit at more than one point. I understand the concept of current flowing through earth in this case but I don't know what the implications are.

I'm just trying to understand the concepts so since this thread started with a discussion about codes for wiring it seems appropriate to do so.

Peter

matt4x4
07-06-2006, 01:37 PM
Well, this is a real grey area with the NEC, first off, when it comes to bonding and grounding, they are two different things, but are essentially the same thing.

Bonding means the connecting of metal object together. But in order to do proper bonding, the bonding has to tie to the Ground rod of the electrical system, otherwise the bonding is incomplete and essentailly does nothing other than making everything metal live when an electrical malfuntion occurs.

Grounding really just means connecting your electrical system's ground to an acceptable grounding location, that being the ground rod.

Now, I know John said not to ground to numerous points, this is where it gets really vague because the NEC states that you have to but are not limited to having ONE ground rod, one is the minimum, but it is acceptable to have secondary ground rods, they have to be tied together or be connected to common ground.
Since your pool rod and your house rod are in the same ground, and are connected to the same bonding wire (remeber that 12 guage back to the panel...) they are essentially tied together twice, once through the 12 guage, once through the ground/dirt. I believe the ground does not count since there is no sure way of telling whether or not the ground the pool sits on is connected to the ground the house sits on unless you have a geological study performed, and another factor is the distance between the two rods which could be so large that the resistance in the ground/dirt becomes big enough to make them two different grounds.

From what I can get out of the code (interpretation) you are doing NOTHING wrong by adding a ground rod to the pool, you are actually just ensuring a good solid working ground connection at that location exists, this really just comes into play for such acts as lightning, I'm not sure what I have for guage at the pool ground rod, but it's easily the thickness of a finger, looking at the other metal objects that are grounded around the outside of my house, it looked like #8 was the common denominator for what was used, then again, that's probably also the spool the electrician had for doing the inside bonding, so he just used it on the outside grounds as well.
I can tell you one thing, the house we have (custom built 3 yrs before we bought it) was extremely overbuilt, everything, and i mean everything, was absolutely perfect when we got it, there were a lot of "don't need it but nice to have it" things and the "wow, now that's a good idea" things, so it makes me think it was all done above and beyond the basic requirements.


It's all very confusing, it all ties to ground in the end,

roxy
07-06-2006, 06:08 PM
May I add.....you shouldn't be in the pool during a lightning storm. Sorry couldn't help myself.

matt4x4
07-07-2006, 07:27 AM
Roxy - I totally understand that, but when parents are out and teenagers are home, common sense sometimes goes out the window! Alsao, sometimes, it seems like a thunderstorm is a loooong ways away, you're in teh pool, starting to think it might be time to get out because of the approaching storm, when BANG, a rogue lightning hit. I understand it's probably a 1 in a billion chances, but hey, dung happens....