I had an interesting question asked to me. You know the cups for a ladder to an inground pool has to be bonded. We will all agree on that. If there are two indiviual cups, then both cups need to be bonded. However what happens if there are two cups but they are bolted tight to a metal tie bar. This bar is going to keep the two cups support at just the right distance so that the ladder will slide in after the concrete is poured. Do you need to bond to each cup? Will one bond wire do? You don't have to bond to each indiviual panel on the pool because we will accept the bolts as acceptable. Right? Second question, why would you still have to bond to a diving jig, when most diving boards are all made out of fiberglass? Most companies still bond the jig, but is it still needed?
Harold: It's better to err on the side of safety. I don't think that the NEC specifies a situation with a "rack" between the cups. As to the diving board base (jig), if it's metal, then it gets bonded. Maybe someone could lay down under the board and touch it? WE bond everything thats metal, excluding the "clips" that hold the winter cover on. They are under the minimum size that the NEC states. HotLine1 John
Re: Pool bonding#81585 09/05/0206:37 PM09/05/0206:37 PM
Just curious, How many points around a pool do you usually require to be bonded?
What I am used to is diagonal corners on a Built-in plus all metal cups and diving platform, Slide supports, etc. On an above-ground we do every other metal Upright plus a tail for the ladder. I've recently read on a BB that someone only had to provide one bonding point on an above-ground pool which seems a little 'skimpy'. What does everyone else require or do?
Re: Pool bonding#81586 09/05/0207:30 PM09/05/0207:30 PM
If you read the NEC verbatim, It says that the pool liner (metal or rebar) is your grounding grin. Everything must be bonded to that. If you run a #8 cu wire from the steel to a pool ladder, pool to a cup(s), pool to the motor, etc. Then all should be OK. There is no requirement for any amount of bonding points. For the above ground pools, I believe the code says that one is all that is required. As others point out, the NEC is a minimum. However, I don't think that I can enforce more than 1 bonding point unless the NEC says so. I would prefer 2 or 3 myself, but I have to enforce what the NEC says. Which is why my original question was about. If the 2 cups for the ladder were effectively bonded together on a strap, and bonded to the pool at one point, is that a violation of the NEC? I don't think it is. Would I like to see both cups bonded, Sure!
Re: Pool bonding#81587 09/05/0207:33 PM09/05/0207:33 PM
Just to answer your post and to repeat what I said before. I agree with you and Bill, that more than one point of bonding would be better. However I have to enforce the NEC as written. I can't make up my own rules, so if the second cup is effectivly "bonded" together with the first one with bolts and nuts, then I guess I would have to pass the job. Not that it is the way that I woud do it.
Re: Pool bonding#81588 09/06/0211:12 AM09/06/0211:12 AM
There aren't many Concrete pools being installed on Long Island from what I've seen. Many in-grounds here have metal frames bolted together, but continuity can easily be broken with non-conductive joiners or inserted parts (like steps). So that is why we generally do 2 points (diagonally) to the frame.
With above ground pools if you look at 680.26(C)(2) it says that the bonding grid shall be permitted to be the wall of a bolted or welded metal pool. From what I've seen many above ground pools do not have all of their structure bolted together. Some pieces may be screwed together (NG per 680.26(D) and 250.8) or just slip-fitted together. This would mean that they should be be connected directly to the solid copper conductor (via suitable connectors/methods).
I see a sticky situation here though. If this is the correct interpretation of the NEC and the contruction of the pool does not use Bolts it may be near impossible to bond every piece required. But certainly Multiple points would be better than 1. (IMO)
Are above ground pools UL Listed?
[This message has been edited by Bill Addiss (edited 09-06-2002).]
Re: Pool bonding#81589 09/07/0208:51 AM09/07/0208:51 AM
I do agree about a sticky situation. I would enforce two bonding points of an inground if the metal is broken with 2 pieces of plastic such as stairs. As for plastic pools, some inground pools are made up of fiberglass and the only thing that is bonded is the metal coping which holds the liners. Then each piece has to be bonded. No matter what the pool looks like the motor has to be wired as per 680 NEC. Some of the "storeable" pools still use the same motors as the inground pool, so the above ground has to be wired just like the inground pool. Unless you have a double insulated motor (filter) which then has a 25' cord and no place to bond to. By the way, I thought I read somewhere that even if the pool is plastic(fiberglass) there is still suppose to be a bonding wire install for future use.
Re: Pool bonding#81590 09/11/0208:36 PM09/11/0208:36 PM
Was his name NEC by any chance? If not then he's got no business telling you how to do this. I was under the impression that bonding was just that, BONDING. Ground rods are Grounding electrodes used for GROUNDING. Two different issues. But hey I don't do pools so what do I know!