Properly grounded pool

[kevreh]

I've heard about the pool grid and equipment being properly grounded. My inground is about 20 years old, but I've never seen a grounding wire going from the pump/light power boxes into the ground (and into a rod). Looks like they use the ground wire going back to the main panel. The subpanel for the pump/light has a GFI breaker, like these: http://www.breakerbroker.com/universalgfi.html.

Is this safe/acceptible or do I need to do some updating?


Kevin

 

[JohnT]

Kevin,

In the US, pools aren't grounded via the panel or an electrode, although they can have a ground electrode. Canada requires a ground connection. Pools have a bonding system, which consists of a wire that connects everything conductive within five feet of the pool or that contacts pool water, but these things are just connected together, not to any particular point. The bond wire is completely separate from the electrical system. It connects the light housing, pump motor housing (on some newer pumps), heaters, SWCGs, dive stands, ladders, railings, slide bases, the rebar in the deck, steel pool walls etc. to each other.

 

[JasonLion]

The pump, and anything else electrical, should be grounded back to the main panel. The electrical grounds should be all connected together back at the main panel and are typically only connected to the earth at a single point at the main panel.

 

[kevreh]

Well, sounds like everythings' up to snuff. Cautious paranoia subsided

 

[ssabin]

Sounds like your grounding scheme is good, although you didn't describe whether your bonding grid was complete. Do you have a solid copper 8 AWG (or larger) wire connecting your pump motor housing (if not double-insulated) to any other metal components within 5 feet of the pool, including metal ladders or handrails? This wire doesn't have to directly connect to your grounding system (in the U.S.), but simply needs to tie all the metal within the pool's vicinity together at the same voltage level.

Perhaps even more important than this is testing your GFI circuits serving your pool area (including separate general use circuits) periodically.

 

[matt4x4]

The reason we have ground connections as a requirement here in Canada is so that should something go wrong and your pool become "live" everything will be fine since it's all good and grounded - current (the thing that kills you) takes the path of least resistance - which will always be to ground, so if there's a direct way to ground with little resistance (grounding wire) it will not go through you the person being of a higher resistance.
Bonding just ties everything CONDUCTIVE together near a pool but does not provide a grounding point, so should your pump feed wires touch to the bond wire (I would use "short out" here, but the term only applies if a ground exists), everything else bonded within 5 feet of your pool will become live (IE: brought up to the same voltage level of your bonding wire - IE -potentially lethal) The current you will draw from these live components all depends on your ability to pass the current through you to ground - usually enough to harm you nicely - this is all done in attempt to keep the US Gene pool relatively clean.

A Master Electrician friend of mine cannot make sense of the US bonding system, he's tried to figure it out many times, and always comes back to the same conclusion, if your bond doesn't directly tie to a ground (specifically stated in the US electrical code that grounding a bond is a NO NO) it becomes a potentially lethal weapon and really has NO PURPOSE.

Kevin's setup is a grounded system.

Now, one thing that can be said about a bonding system is that in all likely hood, it is grounded as well, due to the fact that the pool and anything bonded is not suspended in thin air, rather, it's all sitting on the ground, making contact, therefore, essentially grounded - just not through a ground rod that pretty much guarantees a good connection by going deep and into wet (conductive) soil.
The concrete that the rebar is embedded in is also bonded (because concrete also has conductive capabilities) however, there is resistance in all this - something that is almost non existent in a grounded system. So if your personal resistance to pass current to ground is lower than any of the resistance found in the bonded components - you're the path of least resistance.

 

[JohnT]

US Code doesn't say grounding isn't allowed, just that it isn't required. The reason the US doesn't mandate a ground is the fact that ground points at different locations are not at the same voltage, and the act of connecting the bonding grid to a single ground can and does cause current to flow through the pool and the swimmers in situations where poor utility company grounding practices are used or nearby equipment is improperly wired or defective. Stray voltage is often a problem, especially in rural areas where there is significant distance between homes.

US code compliant pools are grounded via the pump motor bonding lug and its equipment conductor unless the motor is double-insulated.

This was very heavily and rigorously debated before code was changed to specifically state that the ground wasn't a requirement. People often find that there are several volts between their grounding electrode and the bond wire when they remove the connection.

 

[MikeInTN]

Interesting topic. The electrical inspector for the city where I live here in middle Tennessee required my pool to be grounded, as well as the pump motor. I have a grounding rod next to my pump that both the pump and pool connect to.

 

[From_Arizona]

Along the same topic.... I am instaling 5 solid copper scuppers on the back eall of my pool. They are connected to the PVC pipe for the water that will flow through them. Each scupper comes with a screw to attach a wire to, I assume that I need to ground this back to the pool. Is this necessary since the copper scupper does not touch anything metal? If it is necessary, I can connect it back to an exposed rebar on the pool shell, but i do not know what guage wire to use.

Does anyone have any advise?

 

[JohnT]

Along the same topic.... I am instaling 5 solid copper scuppers on the back eall of my pool. They are connected to the PVC pipe for the water that will flow through them. Each scupper comes with a screw to attach a wire to, I assume that I need to ground this back to the pool. Is this necessary since the copper scupper does not touch anything metal? If it is necessary, I can connect it back to an exposed rebar on the pool shell, but i do not know what guage wire to use.

Does anyone have any advise?

To be to code, they should be connected to the bond wire. It's not whether they touch metal, but what could happen if they were to touch something at a different voltage than the rest of the pool. If they were grounded and the rest of the pool had a 220V line in it, or vice versa.