Electric shock when SWG is on

Dirk

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Nov 12, 2017
6,133
Central California
A bonding grid can only equalize the voltage everywhere if there's no current flowing.

If current is flowing, the voltage will be different at different places depending on the current and resistance
Ah, thank you. This is how I interpret that: because of the nature of the different materials involved in the construction of a pool and surrounding deck, and the difference in electrical resistance of those materials, a stray current can introduce different electrical potentials around the pool, and so depending on where you are in the pool, and where the bonding points are, you could still feel a shock? Which would mean that while a bonding grid can significantly reduce the danger of stray currents, it can't eliminate 100% you feeling a shock. Something like that?
 

JamesW

TFP Expert
Mar 2, 2011
20,337
Which would mean that while a bonding grid can significantly reduce the danger of stray currents, it can't eliminate 100% you feeling a shock. Something like that
Basically, yes. If the grid was isolated from the world, the voltage would equalize and no current would flow. However, the grid is connected to the earth and current will flow. The voltage will drop based on the current and resistance.

Go to 17:00 in the following video to see how voltage can change at different places in the water with current flowing.


 

Dirk

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Nov 12, 2017
6,133
Central California
Holy voltage, Batman! I watched most of it. Even with a properly bonded pool, if it gets energized it's still hazardous. Yikes. Mark (above) beat me to it. Very interesting that a pool wiring specialist refuses to have any metal or anything electrical in his pool!! So it would seem that bonding, grounding, wiring, GFCI all have to be in place, and working properly, to even consider your pool safe(ish)!

The video also left me wondering even more about something I wondered about before. He showed how the potential can exist between a bonded section of concrete and one that is not bonded. Granted, it was 4' away from the pool, but it all gets wet. What happens when you have one foot on bonded deck and the other on un-bonded deck?

Anyway, thanks for the video. But it just drove home the point that I try to share around here, even if ignored: most of us don't know what we don't know about pool electrical, and have no business working on or even troubleshooting our own, or advising others how to do it (IMHO).
 

markayash

Gold Supporter
Mar 21, 2016
2,405
Marietta Ga
Holy voltage, Batman! I watched most of it. Even with a properly bonded pool, if it gets energized it's still hazardous. Yikes. Mark (above) beat me to it. Very interesting that a pool wiring specialist refuses to have any metal or anything electrical in his pool!! So it would seem that bonding, grounding, wiring, GFCI all have to be in place, and working properly, to even consider your pool safe(ish)!

The video also left me wondering even more about something I wondered about before. He showed how the potential can exist between a bonded section of concrete and one that is not bonded. Granted, it was 4' away from the pool, but it all gets wet. What happens when you have one foot on bonded deck and the other on un-bonded deck?

Anyway, thanks for the video. But it just drove home the point that I try to share around here, even if ignored: most of us don't know what we don't know about pool electrical, and have no business working on or even troubleshooting our own, or advising others how to do it (IMHO).
My experience is most plumbers and I heard electricians don’t like working on pools. Maybe due to not fully understanding them and liability?
 

Dirk

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Nov 12, 2017
6,133
Central California
Huge liability, for sure. When I suggest to others that they hire a pro, I always add "one that specializes in pools." I was speaking with an electrician at his booth at a county fair one time, about bonding, because I was trying to learn more about. The scary part was: not only was it clear that he didn't fully understand bonding, he was pretending that he did! Of course, I should have known better. Based on what I now know about pools, from TFP, it's staggering how little my [now fired] licensed, professional pool maintenance company knew about the topic! And that includes the owner and his #2, not just the summer-morons they'd send out to my pool. Ya gotta interview contractors now-a-days to determine if they know what they're doing. That's not supposed to be our job, but it is now.
 
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markayash

Gold Supporter
Mar 21, 2016
2,405
Marietta Ga
I had a question about how to wire my timer behind a GFI and ask on a electrician board and was basically called names for asking.
I wasn’t asking how to rig anything I was asking how to make it safe.

Luckily we have people hear like Allen who told me what I was doing wrong. It was my misunderstanding on how a GFI worked.
 

sean.a.hyde

Well-known member
Jun 5, 2018
119
Pittsburgh, PA
We also determined it is indeed the SWG that is leaking voltage.

How did you determine this?
Is the SWG on a gfci?
+1 on this. "Leaking voltage" is a weird term to use -- strictly speaking, voltage doesn't "leak", current does (due to a difference in voltage).
Assuming the SWCG is on a GFCI (please say yes!), the GFCI should at least ensure that all current flowing from the "hot" bus bar is at least flowing back through the neutral (or the two legs are balanced if 240V). I believe this is why bonding problems are generally related to issues before the breaker (eg: a bad neutral to a subpanel), or a completely different component that isn't on a GFCI (A/C unit, etc).
 

Dirk

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Nov 12, 2017
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Central California
Hmmm, I didn't think GFCI was necessary, or even recommended, for a SWG. My pump has the proper Pentair breaker, and my pool light is definitely on GFCI. But the rest of my stuff is not: EasyTouch and all of its connected gear: actuators, IntellipH, IntelliChlor, heater, etc.
 

sean.a.hyde

Well-known member
Jun 5, 2018
119
Pittsburgh, PA
Hmmm, I didn't think GFCI was necessary, or even recommended, for a SWG. My pump has the proper Pentair breaker, and my pool light is definitely on GFCI. But the rest of my stuff is not: EasyTouch and all of its connected gear: actuators, IntellipH, IntelliChlor, heater, etc.
Hmmm. ALL of my stuff is on GFCI. In fact, my inspector was so ornery, he insisted the 50A GFCI feeding the pool subpanel wasn't good enough, and wanted individual GFCIs for all the equipment.
A GFCI wouldn't fix your problem, but it might stop someone from being killed..
 

ajw22

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Jul 21, 2013
19,385
Northern NJ
Hmmm, I didn't think GFCI was necessary, or even recommended, for a SWG. My pump has the proper Pentair breaker, and my pool light is definitely on GFCI. But the rest of my stuff is not: EasyTouch and all of its connected gear: actuators, IntellipH, IntelliChlor, heater, etc.
Page 7 of the IntelliChlor Power Center manual shows a GFCI CB is specified. https://www.pentair.com/content/dam...ower-center-manual-ic20-ic40-ic60-english.pdf

Or if you connect it through the ET pump relay then you should be piggybacking on the pump GFCI CB.

IntellipH uses the same Power Center as the IntelliChlor and the same GFCI requirement applies.

Gas fired pool heaters require a GFCI (680.28) but I think that is a fairly recent code change and you may be grandfathered.
 
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Dirk

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Nov 12, 2017
6,133
Central California
Thanks Allen. Yes, my IC and IpH, both on the same power supply, are wired to the pump relay, so maybe I'm covered. My "electrician" was the same moron that left half the bonding lugs unconnected, and the very same guy that destroyed my pool with the acid wash. He's the go-to guy for my town's main pool maintenance co. So I can't really trust anything he did. If I go out and push the pump's GFI test button, that should tell me what is protected by it and what isn't (whatever turns off!). Or I could follow my own advice and get a qualified pool electrician to double check everything. Ha, well now that the shoe is on the other foot, I'm not sure how well I like that advice!! ;)
 

JamesW

TFP Expert
Mar 2, 2011
20,337
IMPORTANT: When using IntelliChlor ® Salt Chlorinator with an IntelliTouch ® Control System, EasyTouch® Control System or SunTouch® Control System, it is recommended to wire the Power Center to the PUMP SIDE OF THE RELAY located in the automation control system load center.

This method does not require a ground fault circuit-interrupter (GFCI) to protect the circuit.
The cell gets power from the secondary side of the transformer, which won't be protected by a gfci.

If you had a variable speed pump directly connected to a gfci breaker and a different breaker feeding the line side of the pump relay, the breaker doesn't have to be gfci.

At this point, I don't think that we can definitely say where the stray current is coming from.
 

Dirk

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Nov 12, 2017
6,133
Central California
Just tried it. When I test the pump's GFI, IC and IpH go dark, so I think I'm good. Pool and garden lights are on their own dedicated GFI. Everything that has a bonding lug is connected to my bond wire. Not sure about the heater, I've never turned it on. Still rattled a bit by Mike Holt not allowing any metal or anything electrical in the water...
 

Dirk

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Nov 12, 2017
6,133
Central California
The cell gets power from the secondary side of the transformer, which won't be protected by a gfci.

If you had a variable speed pump directly connected to a gfci breaker and a different breaker feeding the line side of the pump relay, the breaker doesn't have to be gfci.

At this point, I don't think that we can definitely say where the stray current is coming from.
So are you saying... if something happens to the SWG that would cause a GFI fault, that "event" won't pass through from the secondary coil of the transformer to the primary, and so the GFI protecting the primary will not trip? Then is nobody's SWG GFI protected?!?

At least my SWG and IpH are wired as per Pentair's spec.

Sorry, I hijacked this thread. I'm not the one with the "shocking" SWG, I've been reading along and spotted something that might apply to me, and all of us that have SWGs.
 

Dirk

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Nov 12, 2017
6,133
Central California
If you had a variable speed pump directly connected to a gfci breaker and a different breaker feeding the line side of the pump relay, the breaker doesn't have to be gfci.
That's what I have. The pump (and the IC and IpH) are all on my Pentair GFI. The ET is on its own breaker, but that is not GFI. My lights are wired to the load side of a 120V outlet that is mounted on the outside of the ET. My heater is on it's own breaker, but also not GFI.
 

Dirk

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Nov 12, 2017
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Central California
Hmm, now that I think about it, I'm not sure. Did the IC and IpH go dark because they are actually powered by the pump's GFI, or did the ET shut them off when it sensed there was no power to the pump, and the IC and IpH are actually getting power from the ET circuit? I'll have to go check that in daylight... I have the external Power Center for the IC and IpH, not the internal transformer.

I supposed I could just replace the three non-GFI breakers in my pool's panel with GFI, and solve it that way.
 

ajw22

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Jul 21, 2013
19,385
Northern NJ
I think the voltage and amperage on the cell side power are too low to be lethal. Every SWG feeds electrical power directly to plates that are in contact with the water.
 

Dirk

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Nov 12, 2017
6,133
Central California
I think the voltage and amperage on the cell side power are too low to be lethal. Every SWG feeds electrical power directly to plates that are in contact with the water.
I'd like to think that Pentair (all SWG manufacturers) thought of that and use a transformer to step down the voltage for that very reason.