Stray Electrical Current Trouble-shooting

[Shallowwaters]

Any EE's out there willing to help on this one?

I found stray current in my sump yesterday - the kind that you feel only through a cut on your hand. After unplugging EVERYTHING and systematically testing devices, I found two items introducing current into the system. I must have shocked myself 30 times in this rediculous experiment...

Here's where I found the current coming from:

1) my chiller - whether running or not. How does this happen? Happens with or without the controller plugged in-line.
2) my titanium grounding probe! How in the heck does a grounding probe introduce current? I live in a new house with very good electrical wiring. I tested two outlets on two different circuits - one GFI and one that was not. Same problem in both cases.

Can I fix the chiller problem or do I have to get a new one?

And, yes, through the process of elimination, I actually put my hand in to solve an electrical problem WITHOUT the grounding probe in the system. I'm here to tell you about it, thank goodness...

 

[~Flighty~]

Could you maybe use a voltmeter next time? We don't want to have to pick up the slack in the BOD if you hospitalise yourself.

 

[synchiropi]

This does not answer your question, but I have Sky's Tunze stray current detector. Might be less painful the next time.

When having my own little electrocution going on, I found that having one of my multiple power strips powered on, EVEN without any device plugged in it would create a current flow!!!

Nevertheless, with my voltimeter, I found that the amount of flow was very little, so I got my grounding probe and c'est fini. I wonder sometimes if there is some minimal salt creep onto the wires or surfaces that might cause the flow. Time to wipe everything very clean.

Electricity always finds its way I guess.

 

[Shallowwaters]

Ahh, a voltmeter. Wish I had thought of that!

 

[Aquaman_68]

Mark, Stray current will go to ground. That is the explanation for current in the ground probe. (Like the current zapping you when you put your hand in the sump) the current is going to ground or in another case.... YOU !!! Looks like you may have a problem with the chiller if it still happens when the controller is unplugged & the chiller is plugged in to run continuous.
HTH
B

 

[clamm]

The only way a grounding probe can introduce current is if they hooked up the circuit wrong and made the ground hot. Which would be a dead short and pop your breaker, so I doubt thats the issue.

 

[Shallowwaters]

No joking -
ground probe in = small shock
ground probe out = no shock

What's up with that?

There is a complete circuit of some kind, so that rules out corrosion on the probe as a cause for failure to ground the system.

And if my ground wire was hot, wouldn't I have bigger problems throughout the house?

 

[~Flighty~]

Just out of curiosity, do you get lots of radio interference when your MH and actinics are all on? especially on AM.

 

[Shallowwaters]

Just out of curiosity, do you get lots of radio interference when your MH and actinics are all on? especially on AM.

Not that I have ever noticed.

The chiller mfg says stray voltage is not uncommon with a chiller, but it's weird to have this happen when the chiller is not running. They are checking on this for me.

Because this is related to the chiller and the probe, I am concluding that I have a problem with ground loop somewhere in my house that is putting a charge the ground wire. The chiller is probably incidental and just passing it into the system.

The kind of interference you refer to can also be caused by a ground loop. And that can happen if MH reflectors are collecting a charge. (Chiller guy told me they can do that.)

Hopefully, this is easy to find and fix - if this is the problem. Good thing I got a cut on my finger to find this problem!

 

[PenMan]

Let me know if you want to borrow one. Have a couple meters at home.

 

[~Flighty~]

I think this is probably karma from razzing you about testing the water with your hand - I found the same problem in my fuge last night. I think the only thing it could be is the canister filter in there. I'll wait to trouble shoot it until Eliot gets home and I can make him stick his hand in to test it

 

[Stanley Wong]

I think you may have a floating ground, ie., the ground (green wire) may not tied to the earth ground. Do you have the rubber shoe/slipper on when you touch the water with your hand ?

 

[offshore]

You can buy a groung checker at HD for a few bucks. It plugs into the plug you want to test and tells you if it is hooked up right or there is power at the ground. One plug wired wrong in the house will affect the whole system!