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

[craigwmiller]

Thanks for the props on the knowledge My background includes network (primary) and electronics engineering, and practically running a datacenter with massive electrical requirements, gensets, specialty grounding, well you know

And yeah I had the same nervousness from GFCI, but the safety was too important to me -- so I installed 4 circuits, downstream from UPS backup, with all the equipment and pumps spread among each circuit - so the tank could sustain itself for at least a couple days with some circuits tripping, so long as not all of them go out... current project is to add to that an automated e-mail & text when all power goes out to the tank (via breaker, or downstream gfci)... all this is at least as much fun for me than the actual reef keeping


Now to the problem at hand, there is undoubtedly something up with the skimmer -- but I'm going on a trip in a week so I don't want to change anything in the tank while I'm not around to monitor... but due to the same thing, I will not have pH monitored while I'm away (not the end of the world).

I will do some testing though with it -- I'm thinking a separate bucket of water with the skimmer doing it's thing and the pH probe - to at least eliminate the interaction between the skimmer and something else or the pH probe and something else... full test, another separate circuit, etc.


Now, another question for you (or anyone) related to testing electrical... Will a conductivity test offer any insight here? pH uses reference voltages, right?, and if there is some resistance to ground between different devices, things could be strange... Possibly I'm thinking that the ground from the skimmer is somehow exposed (but if just ground exposed, not a real issue), but perhaps with a higher resistance -- just brainstorming as I'm typing


Cheers!

[Baldy]

I don't know enough about conductivity to comment nor do I know anythinabout how ph probes work. I can help with the grounding bit but the test is a bit beyond my knowledge

[Baldy]

just a stab in the dark here, but is there any chance that the aeration from the skimmer is affecting the readings?

[KrazyKuch]

a conductivity test is more or less the same as a salinity test or tds, ph probe is basically a device that generates a voltage....A ph meter is just a high impedance op-amp(amplifier) the voltage is generated by the probe itself (mV)...How close is the probe to the skimmers output????

[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.