Electrical Terminology & Safety Tips

[CarlD]

In my town EVERYTHING metal must be bonded--unless it's not attached, like a solar reel.

But my ladder, my drop-in steps handrails, the pool structure, cross members ALL had to be bonded, as well as, of course, the pump.

Codes don't always make sense but they always must be obeyed to the inspector's satisfaction (!).

Insurance companies won't pay a claim if you needed a building permit and didn't get one. It's as simple as that. If you have an "outlaw" pool and someone gets hurt, Ol' Indemnity Plus will let you swing in the breeze.

[BigTallGuy]

The main idea is to ground all the various components of your pool together with copper wires. You can use Bare or insulated wires, and somewhere there could be a code dictating a wire size, but in my mind, all these grounding wires need to be grounded directly to the GFCI ground wire or the (Green) Grounding screw. Twist them together, use wire nuts, crimp them together, even solder them, but the "Final Run" goes back to the GFCI.

[Ohm_Boy]

Bonding and grounding are often confusing subjects, and are not the same.

Bonding refers to connecting items together. All metal objects which can come into contact with pool water should be bonded together. This prevents any one of them from becoming a different potential from any other, from whatever influence, direct electrical contact, induced current, chemical, etc. This bonding prevents any current flow through the water itself, thereby protecting the occupants.

Grounding, on the other hand, indicates a connection of one or more components to the service ground, equipment ground, ground rod, or other ground-potential reference point. Technically, there should only be one ground reference in an electrical installation, and that is most often at the service feed point. Everything else which is to be grounded should tie directly to that point with minimum resistance.

Technically, in a grounded system, bonding is simply a means of connecting the ground wires to everything. In an ungrounded system, a bond wire just connects it all.

There is also much debate over whether or not a bonded pool grid is to be grounded, and as I understand it, there are differing local code requirements as well. Some say ground, some say isolate. I'm personally a "ground it" fan.

As an aside, the GFCI protected circuit does not need a ground connection to the GFCI to be protected. GFCI devices are designed to measure differential currents between the hot and neutral conductors, and open the circuit if that difference exceeds the trigger, around 5 milliamps. It is assumed that any difference in current is being diverted out-of-circuit by a body somewhere. Naturally, a ground is required by the circuit according to code, but it is not necessary for the GFCI feature to function.

[BigTallGuy]

As an aside, the GFCI protected circuit does not need a ground connection to the GFCI to be protected. GFCI devices are designed to measure differential currents between the hot and neutral conductors, and open the circuit if that difference exceeds the trigger, around 5 milliamps. It is assumed that any difference in current is being diverted out-of-circuit by a body somewhere. Naturally, a ground is required by the circuit according to code, but it is not necessary for the GFCI feature to function.

O.K. I bonded My pump motor and SWCG control unit together and ran the Bonding wire to the ground of the GFCI, if current from any source (say a bad extension cord as a bad example) was to somehow enter the Bonding/Grounding wire wouldn't that trip the GFCI? Or Does the GFCI only measure the currents between its own conductors?

[PoolDoc]

Just wanted to jump in here, because this is a critical subject, and some of the answers may not stand out to people.

1. Bonding and GFCI's protect people,
not equipment.

2. Breakers and fuses protect equipment.
People not so much, except indirectly by preventing fires.

3. Licensed electricians are better than unlicensed ones . . . usually,
but in my experience, many licensed electricians, and some inspectors, are clueless around pools.

4. To fully protect people, you should BOND every fixed piece of metal a wet swimmer could touch.
(Codes may require more or less than this. You should obey electrical codes, too. At least, most of the time. Or if you are going to be inspected. )

5. Codes sometimes allow discontinuous bonding via the rebar mat. This is NOT a good idea.
Sometimes what was a continuous electrical connection in the mat becomes discontinuous. Use a full length bare copper wire, from start to finish.

6. Codes sometimes allow conduit grounding. This is another bad idea, around pools.
Conduits get disconnected: been there, got the shock, cussed out the electrician. Fortunately, did not die! Use a continuous wire ground around pools.

7. All bonding mats are "grounded" intrinsically.
But, if you ground to the box, you can get currents going. I don't like unplanned currents around pools. So, if you 'ground' your bond wires to the box, use a BIG wire for the bond and a SMALLER one for the ground-to-the-box connection. There are obscure electrical reasons for doing this. By the way, if your pump is correctly wired AND bonded, your bonding system will ALWAYS be connected to your ground system. (Unless you are using conduit grounding -- see below.)

8. Grounding your 'bond' system to your box or panel can prevent weird corrosion issues.
Again, not gonna explain this. But it's much better to prevent these sorts of issues than figure them out.

9. Make FRICKING sure that you have a CONTINUOUS wire ground from your local wire panel back to your main distribution panel.
Code may not require this, but you should. Again, got the shocks on this one. No, I do NOT like conduit grounds. Ever. Except maybe in the dry desert. Not near pools. Not in wet restaurant kitchens (where I got fried, while working as a plumber.) Maybe where nothing but camels and horny toads live. Or, maybe not even there.

10. Shocks and wet people who want to keep living don't go together.
Electricity can usually find an easier path to follow, than through a dry person with shoes on. Electricity can usually NOT find an easier path to follow than a wet nearly naked person. You have to work specially hard around pools to make sure that the easiest path is not through you, your family or friends!

11. Think about the drips!
And, I don't mean the jerks who become your close friend right about the time your pool is being finished. I've seen a lifeguard get a bad shock because they 'dripped' into a GFCI protected receptacle that was mounted horizontally, rather than vertically.

12. Speaking of GFCI's, they fail around pools. A lot.
Sometimes they fail 'safe' tripping every time you look at them. Sometimes, they fail 'DANGEROUS', and won't trip when you try to weld your extension cord to your pool ladder. (Or, when a lifeguard drips into the receptacle!) Check yours today, and several times each season. There's a GOOD reason for that little red or yellow button on your GFCI.

13. Do not bring electricity into the pool area from outside the pool area.
OK, I confess. I'm the idiot who did this, with an extension cord. All those electrical safeties in your pool area don't mean squat if you drag electricity in from elsewhere. Not one of my brighter moments. Pay for a 20A receptacle off the pool panel, when you do the pool.

14. Electrical boxes should not be closer than 12" to the dirt. Ever. No matter what the code allows. When you put electrical boxes in the dirt, or even that close to the dirt, they WILL get wet and dirty. Probably not while there is still a warranty on the work, but soon after. Every SINGLE 'sealed' commercial pool light junction box I've ever opened was full of water. In fact, "sealed" electrical boxes seem to be much better at keeping water in, than at keeping it out.

Hm-m-mh, that's all that comes to mind, right now.

Ben
"PoolDoc"

[CarlD]

Ben put it well:

GFCIs are to protect people from electrocution. They do NOT protect the circuit from too much current. The slightest imbalance between the hot and neutral should trip them.

Breakers and fuses protect the circuit from too much current so the wires don't heat up and start a fire.

Too many workman pull out the third prong on plugs. This is, frankly, insane, especially when they work outdoors. My father did that constantly and to this day I'm amazed he died of lung cancer and not electrocution! I pulled apart his bench lathe as we were selling the house for my mom and in the switch box...he had bypassed the ground yet again! (the lathe is powered by a Jacuzzi pump motor--with Dad cutting out the ground). The switch went into the trash! When the lathe is set up again, it will be wired correctly.

Most towns and cities don't allow "Conduit grounding" or, more properly, a "mechanical ground" requiring, instead, an electrical ground.

For bonding, my town requires the ground to be insulated and green-jacketed. Also it's something like #8 wire--very, very heavy and everything metal is connected to it.

[bhawleyusa]

Do aboveground pool codes differ? I have a oval 33' that is one large sheet of steel connected together at the skimmer. There is a wooden deck surrounding the pool. The 110v pump uses a 3 prong plug into a GFI connected to the main panel thru 4 conductor romex. All pipes and ladders are pvc. Should the pump be bonded to the pool? Should there be a separate ground from the pump to the panel ground?

[Skioutty]

14. Electrical boxes should not be closer than 12" to the dirt. Ever. No matter what the code allows. When you put electrical boxes in the dirt, or even that close to the dirt, they WILL get wet and dirty. Probably not while there is still a warranty on the work, but soon after. Every SINGLE 'sealed' commercial pool light junction box I've ever opened was full of water. In fact, "sealed" electrical boxes seem to be much better at keeping water in, than at keeping it out.


I'm an electrician for 24 years and have never seen a dry pipe in the ground ever. They will have water in them from plain old condensation.

[PoolDoc]

Interesting, Skioutty.

I'm not an electrician, but I've had that experience as well. However, I've continued to assume that somewhere -- just not where I was -- there were waterproof boxes that worked. Hadn't thought about the condensation aspect, but given the air / dirt temperature differential, over much of the summer, that makes sense.

I'd be interested in your reaction to conduit grounds, and particularly, grounding via EMT and PVC coated metal flex. I have personally come to DESPISE conduit grounds.

Ben