Stray votlage

Ian · #1 12-27-2010, 11:01 PM

So I i am leak testing my new set up and upon touching the water in the sump i get the nice little tingle of significant but not harmfull stray voltage. So I begin to shut down possible sources and determine that all is coming from a quiet one 4000 pump I am using temporarily. This pump has been nothing but headaches from day one so no suprise. I pull it out and use the reminder to hook up my grounding probe.
Here is where is gets strange
I then start the water flowing and once again feel the tingle of stray votage ...WHAT THE F>>>>>..... So I go through the detection process again.....guess what the source is....THE GROUNDING PROBE!!!!! no kidding it was the problem. I pulled it out and all was well with the world....not exactly sure how that worked but I do know it was what happened....

Strange...

wingedfish · #2 12-27-2010, 11:12 PM

not exactly sure where a ground probe grounds (assume it's house ground) but you should check to make sure your house wireing is good. With a meter, check your wall socket blades to ground. One should be 120 or so the other should be zero. If ground in the house is broken somewhere and something in the house is shorting to ground, then ground becomes live.

Worth checking out for sure as the ground probe should not induce voltage in any way.

mike31154 · #3 12-28-2010, 01:53 AM

Here are a couple of links to what I consider some good info on grounding probes & GFCI devices. Personally I don't use a grounding probe, but do use GFCI devices for all my tank equipment, more than one for redundancy.

http://angel-strike.com/aquarium/GFI...alDetails.html

http://angel-strike.com/aquarium/GroundingProbes.html

I also agree with some of the points wingedfish brought up. It sounds like wherever you had your grounding probe attached, there is a problem. If it was a ground on a wall receptacle, it wouldn't be a bad idea to get hold of one of those receptacle testers available at most reno centers these days. This handy little device will tell you right away if one of your receptacles is improperly wired or has a bad/missing ground.

Ian · #4 12-28-2010, 05:20 PM

Yeah gotta get a tester today and do some searching....

sphelps · #5 12-28-2010, 07:17 PM

The problem wasn't really the grounding probe it's functioning properly. Using a grounding probe will promote stray voltage. Typically most pumps will produce a small amount of stray voltage but it will stay localized at the pump unless a ground is introduced giving something for the current to flow towards. This is partially why I don't believe grounding probes are a good thing, they simply promote current flow through your tank which is the dangerous part and if combined with a GFCI it can cause it to trip and cut power when a problem doesn't really exist. Use a GFCI for safety but ditch the grounding probe, it's not helping you.

mike31154 · #6 12-28-2010, 09:18 PM

In the first post, the OP said he felt a tingle until he removed the grounding probe. If current was flowing from a piece of faulty equipment through the probe to ground, he shouldn't be feeling a tingle. This makes me suspect that he may have a faulty receptacle (or wherever the grounding probe was 'grounded') and that this is actually introducing a voltage potential into the tank and when he put his hand in the water, becomes the return path. This is why I suggested he investigate his house wiring.

But again, yes, I don't personally use grounding probes because their presence can actually hide or mask a problem all the while giving you a warm and fuzzy because you have one installed. Power can be a funny character, lots of gremlins in the wiring. GFCI is the way to go for your personal safety.