Hey, a thread I can help on. I just spent all weekend researching this stuff because an issue came up on my build.
Ahem (clears throat). According to Section 680.26(B)(1) of the National Electrical Code 2011. Its sad that as a homeowner I can quote the right section from memory, But I ended up having to read it. And then reread it, until I fully understood it.
Anyway the rebar sticking up is supposed to be part of the conductive pool shell. The section number I quoted deals with it. The structural rebar they leave is acceptable as a point of connection for electrically bonding to the pool shell bonding 'circuit'. Usually they run a bonding wire - as many have noticed this is a size 8 AWG solid bare copper wire, usually it runs around inside the pool, is clamped to the rebar at various points, and is also clamped to the shell of any lights. Every point the rebar crosses is tied with steel wire, and this makes the whole rebar cage what they term an equipotential grid - any thing metal must be connected to this grid, including anything the water goes through that can can cause electricity to enter the water - so the pump and heater. Also a 3' area around the pool must also be bonded. The perimeter bonding must be connected in at least 4 points uniformly spaced around the pool. The pool pump and heater also have to tie in to the perimeter bond also. While they often run the bonding wire to the equipment pad, also tying in to the structural metal of the pool shell and perimeter provides a grid and a multipoint failsafe form of bonding, that a single wire cannot provide alone.
If you are still awake and with me, this is why: This way, if there is any kind of short in any of the electrics, you, the water and all the things that you can touch near it are all all have the same amount of electricity flowing through them. Or as it is called the same 'electrical potential'. It is all connected or 'bonded' together. Electricity will always try to take all available paths to a lower potential, the difference between electrical potentials is what we call 'voltage'. Electricity is only dangerous tries to return to a source of lower potential through you. If everything is at the same 'electrical potential' including you, then you are safe. Because you are no longer a route to a lower potential. Its why birds can sit on a high voltage line, and linemen can work on them while electricity is flowing through them. As long as nothing they touch makes a route to something which is not at the same voltage - e.g. the actual ground. People often get confused between bonding and grounding. The earth itself has an extremely low electricity potential and has a basically limitless capacity to soak up electricity, so it is used a 'ground' or a place to send lots of electricity safely. The lights and electrics of the pool get grounded so if there is a surge or lightning strike or fault, the excess electricity goes to ground. But you do not want to be this route it takes, so you make sure that when you are in or near the water, the only things you can be in contact with are all at the same potential.
This is what the rebar is for. Its not for structural support. Its for equipotential bonding. Its to be tied to the rebar/mesh of any deck around the pool, if you don't have concrete decks, then either a mesh or copper wire is buried beneath the pavers or lawn and is connected at at least 4 points around the pool to some of the rebar. The recent build "in Georgia" has great pictures (albeit sideways on!) illustrating this grid before its buried, because they have it set up to add pavers later.
When they put the coping on, at least on my pool, they either added mortar, or beat the rebar into the gunite to recess it (depending on elevation - to level it all perfectly), before mortaring the coping on top. The rebar ends up just sticking out the side of the pool. It will either be cut off if not used, or used to tie into the bonding around the perimeter and buried, either by concrete or below grade.
And that ladies and gentlemen, is more information about electricity and pool bonding than you ever wished you didn't know. Why yes, my weekend was scintillating....
EDIT. Yeah, you don't ground a bonding circuit. It defeats the purpose. Leave it to the professionals on this one. Its part of the inspection line items for the pool bonding and if you mess with it, you will fail your pool inspection.
