Grounding

[PMK]

We've built a waterfall/wading pool that uses an aquarium style submersible non-grounded pump. There is a Safe-T-Cut in the house. Would running a ground wire into the pool make it any safer in case of a short or leak into the pump?

Thanks,

Peter

[george]

I guess this is 12V, instead of 220V ?

[Chaichara]

I guess this is 12V, instead of 220V ?

Hi Peter,

With or without Safe-T-Cut or an extra earth wire, if it's 220V it's an accident waiting to happen. The danger is analogous to driving like a maniac and taking risks, because you now have ABS and airbags to to soften the impact when the accident happens.

If you are safety conscious, and you obviously are, the only solution is to use an external pump that is correctly designed and rated for swimming pool water features.

Edited December 13, 2008 by Chaichara

[Crossy]

I'm going to echo the above ^^^.

Aquarium pumps are not intended to be intrinsically safe, a leak into the pump could kill (I've had shocks from aquaria, the fish don't seem to care).

You must use an pump correctly rated for swimming pools (I'm not a pool expert but a 12V submersible would likely be ok), or why not power the water feature from the outlet of your filter pump?

220V anywhere near a pool intended for bathing is a majo no-no!!!

Edited December 13, 2008 by Crossy

[PMK]

I understand (now) that a 220 V pump is inherently dangerous in any kind of pool and will correct that situation, but as a matter of interest and education, is there any safety benefit at all from grounding the water particularly with a GFI in the house?

Thanks,

Peter

[dotcom]

If the pump comes with a 2 pin plug it's really not designed to be grounded.

I will make a guess here that the pump case is made of plastic or rubber or other non conductive materials. I am not saying it's safe to use.

There are decorative pool fountain suppliers up by Chatujak Market.

[Crossy]

I understand (now) that a 220 V pump is inherently dangerous in any kind of pool and will correct that situation, but as a matter of interest and education, is there any safety benefit at all from grounding the water particularly with a GFI in the house?

No benefit.

In fact is is not practically possible to 'ground' water. Fresh water is actually a very poor conductor so just sticking a ground rod in will have zero effect (the water is already in contact with the ground after all).

The danger comes when a person gets wet, the water on the skin forms a thin conductive layer with the skin oils and salts forming an easy path for electricity leaking from your iffy pump. The leakage would possibly be insufficient to trip the GFI until the person comes in contact/near contact at which point he gets a wallop and (hopefully) the GFI trips (yes you definitely feel a strong shock even with a GFI, you are just less likely to die).

Edited December 17, 2008 by Crossy

[PMK]

Crossy, where would we be without you? . Thanks for the informative and lucid explanation.

Peter

I understand (now) that a 220 V pump is inherently dangerous in any kind of pool and will correct that situation, but as a matter of interest and education, is there any safety benefit at all from grounding the water particularly with a GFI in the house?

No benefit.

In fact is is not practically possible to 'ground' water. Fresh water is actually a very poor conductor so just sticking a ground rod in will have zero effect (the water is already in contact with the ground after all).

The danger comes when a person gets wet, the water on the skin forms a thin conductive layer with the skin oils and salts forming an easy path for electricity leaking from your iffy pump. The leakage would possibly be insufficient to trip the GFI until the person comes in contact/near contact at which point he gets a wallop and (hopefully) the GFI trips (yes you definitely feel a strong shock even with a GFI, you are just less likely to die).