Skimmer Voltage/ground Leak, new pump? Vertex IN-80/100

[craigwmiller]

Good thought possibly static/etc from the bubble velocity/etc...

so I just tried it - I removed the intake venturi from the pump (stopping all air from being drawn in), and let it run a few minutes to calm down -- no difference.

I also then tried moving the PH probe around the sump (and into the display) to rule out distance from electromagnetic fields/etc -- nothing.


I think I've narrowed this down to an induced voltage from the EMF from the pump feeding the skimmer. With my volt meter in DCV mode, I have a potential of 167 millivolts from the tank to ground with the skimmer running, and 0 millivolts with the skimmer unplugged. True this EMF isn't creating DCV, but there is still some detectable as a 'potential' so the skimmer motor is very likely unshielded.

I've done conductivity testing from the tank water through to all prongs of the skimmer cord (and between them) and the impedance is at least 2 million ohms - so let's say there's no connection -- so this must be EMF.

Now, I could definitely just be talking out my A** and chasing a solution that makes sense in my mind (after all the troubleshooting), but it would seem this explains it best (in the absence of a physical leak from any of the 3 conductors to the tank - as identified by conductivity).


Ordering a new skimmer me thinks. Or at least a new pump.

[ScubaSteve]

My gut says noise from EMF, especially if its a conductivity probe (I'm a thusly fairly confident). How close is it to the pump? Can you try putting the probe in the display far away from the pump (or anything else that may cause a similar effect)? If its voltage leak, you'll probably still see the issue. If its EMF related, it should disappear.

[craigwmiller]

After tuns of more troubleshooting I shutoff the main pump which (due to water level) shutoff the skimmer power... SAME PROBLEM.

So, then I removed everything else, and connected just the skimmer grounding pin to the outlet's grounding pin - same problem.

THEN, I took the ph probe into a glass of water (which I've done before), when isolated, no problem.

Then I added the grounding probe to that glass of water, instant difference...


All this on the phone with waynemah to help troubleshoot verbally through everything -- when he come out with:

"HEY! you remember last summer when we were fixing the check valve in your hot water tank, there was those sparks when the water lines touched??!!! Did you ever look into that further??"

bingo, I think the issue is that something ELSE is electrifying my ground, and the skimmer is then (possibly due to bad shielding or simply broken internally) taking the electrified ground and spreading it to the tank.


My wife is out now, back in about 30 minutes -- I'll start testing ground fault potentials when she is around to kick me if I touch the wrong thing... The thing that is causing the problem is probably draining some current to ground, which is a slightly higher potential (possibly just a few millivolts) that the tank is noticing.


As per my last post regarding a DC potential that I have in my system with the skimmer plugged in -- my thought now is that there is a DC short somewhere, and the power is coming IN the skimmer, not out the skimmer... As to why the grounding probe doesn't do anything could be that it's DC, and that's creating a magnetic field or small current via the skimmer that an AC leak would not. Again just ~160 millivolts here...


Thanks for all the input!! Back to you with news (hopefully that I've fixed it, I just hope the thing that is possibly causing me a small short or leak isn't my TV or something else expensive LOL)

[Baldy]

if you are having problems elsewhere in your house, id look into grounding problems with your house itself. check the main ground wire coming off your panel going to your water pipes (usually) for corrosion or other issues.

[craigwmiller]

Okay, time to stop testing and time for bed, but here's what I've found:


From outlets around the tank (far from the panel) the potential between Neutral & Ground is 0.0 -> 0.1 (sometimes, but it just bounces there for an instant so if you blink you'd think it was always 0.0VAC). But on some other circuits (mainly in the basement, close to the panel) the Neutral/Ground potential is up closer to 0.5VAC.

I found two outlets in the house are wired wrong (hot and neutral are reversed). They each only have very minor loads on them. Shutting down these two bad circuits (and their loads) didn't remove the 0.5VAC potential.


Another 2 outlets in the garage (single garage circuit) don't work at all - but their immediate upstream outlet works, so I'm thinking a loose connection inside either the last working or the first non-working outlet... I will check out the garage properly tomorrow when it's light out.


I have not tested quite all the outlets in the house yet - family sleeping, etc... there very likely may be another outlet with a load on it that is wired backwards feeding current incorrectly -- or heck, possibly feeding return current down the ground.


Never a dull moment

Craig

[craigwmiller]

Okay well I fixed the badly wired outlets, and the odd voltage potentials are cleared up - glad nothing bad happened from those.

My skimmer is still still causing an issue though, so after all of the troubleshooting not being able to find a specific problem somewhere else it must be the skimmer.

Last test, before I re-post a request for a pump to try/buy

I unplugged everything inside the water and then tested conductivity between the water and the plug pins, here's what I found:

Pump, 2x Heaters, ZEOvit pump:
Ground or Neutral or Hot (from cord) -vs- sump water... Infinite Ohms (perfect)

Skimmer:
Ground -vs- sump water... 20K Ohms
Neutral -vs- sump water... 15M Ohms
Hot -vs- sump water... 15M Ohms


15M Ohms is high, sure, but there is conductivity there. 20K is very low, considering there should be no conductivity where I was measuring.


I should have done some of this specific conduction testing earlier, but first time troubleshooting something this odd there are so many things to try.


At least I resolved the Hot/Neutral mixup on those two outlets!!!!!


Now, to replace the skimmer pump.


Thanks!
Craig

[Baldy]

How old is your house/electrical? I don't see how you could have any voltage across the neutral and ground at all unless either your picking up inductive voltage from another wire or the neutral isn't properly.bonded in your panel. If your comfortable opening it up, check the jumper/bus bar/screw that bonds the neutral bar in your panel to ground as well. Just another idea.