Stray Voltage – How much is bad?

[redfishbluefish]

With some of the chatter on stray voltage and tingling hands, I throw my VOM (volt ohm meter) into the tank this morning and found 4.5 volts. I know I should probably make like an ostrich, and stop looking for problems.

Anyway, is this something that I should be concerned about? Later today I’ll start pulling plugs to see if I could find the culprit. And, if I find the culprit, is that enough stray that I pitch that unit and buy another? OR, is a little voltage OK?

I did add to the PA group buy a grounding probe. The concern I have with this is that it potentially covers up the problem. I like what one person wrote in an earlier post…unplug the probe on occasion to test for stray voltage.

 

[redfishbluefish]

I started searching stray voltage and now I’m even more confused. (That’s not very hard to do). I like what one page had; “WARNING: THE FOLLOWING DISCUSSION IS NOT FOR LIBERAL ARTS MAJORS. CLICK THE "BACK" BUTTON ON YOUR BROWSER NOW TO EXIT”

http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GFI&TechnicalDetails.html

The confusion is over the use of a ground probe. The old adage, it’s not the voltage that kills you, it’s the current. Stray voltage isn’t necessarily bad…all tanks have some. By putting in the probe, you have now created current…a path for the voltage to take…and that’s bad.

So should I live with the 4.5 stray volts or ground probe it, now creating current?

What do others do? Have you measured you stray voltage?

 

[stcreef]

Well the problem with our tanks and stay voltages will never be overcome. There are too many things we use that will cause it. Let alone the salt water and galvanic actions. Any pump using a magnetic field and submerged in the water will cause a voltage to be induced. This also includes the heaters. 4.5 volts is pretty low from what others have seen. What you want to do is measure the current potential. From your VOM, put one probe in the water and the other to a suitable ground. WARNING: MAKE SURE YOU ARE INSULATED WHEN DOING THIS. YOU DONT WANT TO BECOME THE GROUND PATH IF THERE IS A HIGH POTENTIAL!!!

 

[REEFLECTIONS]

i read a quote in someones profile from another forum it made me laugh, went something like this "i like to put extreme amounts of electicity and large volume of saltwater near eachother" i guess we're all a bit nutty

 

[redfishbluefish]

What you want to do is measure the current potential. From your VOM, put one probe in the water and the other to a suitable ground. WARNING: MAKE SURE YOU ARE INSULATED WHEN DOING THIS. YOU DONT WANT TO BECOME THE GROUND PATH IF THERE IS A HIGH POTENTIAL!!!

Stcreef, I’m not very bright…so help me out here…you say to measure current potential. Isn’t that what I measured when I reported the voltage. Isn’t the measurement of voltage the potential of current. It doesn’t become current until the circuit is complete…i.e. potential.

The actual way I measured the voltage was to put one probe in the salt water and the other on the screw of the light switch. I knew the light switch screw was connected to the electrical box, which was grounded.

After reading a bunch of sites, I’m now leaning towards not putting in the grounding probe. The probe causes current, which is a danger. I am saying this with great ignorance…just what I’ve read.

 

[stcreef]

Most VOM's have a ma(MilliAMP) setting. This will basically complete the circuit and measure the current. Measuring the voltage doesn't complete the circuit. Anything above ~.5 ma you can usually feel a tingling sensation. Above ~3 ma it can start to get painful. Above 10ma and your in a real danger zone. But that has nothing to do with your tank. So I would be curious as to what you measure. In all of the post on different forums everyone always lists the voltage they measure. You very rarely see a current reading.