What to do about stray voltage?

[Jgoal55]

Alright, I asked this in my GFCI thread but figured this was it's own topic and better suited for it's own thread.....

After the Marine Stealth Heater Incident, I decided to test for stray voltage in the aquarium and I have close to 40v in the tank which sounds like way too much. I do have a grounding probe, but I noticed today that the probe itself had rust and the grounding end had corroded and I'm guessing the stray voltage is the cause.

I'm wondering if this might also be the culprit in my struggle to keep some SPS alive?

My return pump is putting out about 11v, Heater about 4v, reactor pump 9v, Skimmer about 9v. Scary part, it's all brand new equipment (well, 6mos old).

When I turn off all the equipment, but leave the Apex EB8 (where all the equipment is connected) plugged in, there is a stray 11v in the tank. When I unplug the EB8, the voltage drops to 0.

What should I do? Shouldn't stray voltage be at 0 or very close to it???

 

[Kayo2289]

Not an electrician but have taken a few electrical classes.. none of that is neccessary however.. no there should be no loose voltage or current running through the water... and yes I would believe that this effects your coral quite a bit..

check all components with wires in the water... may be a small nick in the insulation.. leaching out some voltage.. seems like you troubleshooted the problem to some component of the EB8..

 

[mrx66699]

Use a grounding probe to protect open water current and a multimeter to test then track it to the individual culprit one by one with the meter and turning on and off each item till u find it and replace .....

Sent from my EVO using Tapatalk

 

[treetopflyn]

What would I do? Eliminate it!!

 

[Paul B]

40 volts of "induced" current is kind of normal and I would do nothing.
It is actually induced voltage, not current.
(Electrician 40 years)

 

[Jgoal55]

Use a grounding probe to protect open water current and a multimeter to test then track it to the individual culprit one by one with the meter and turning on and off each item till u find it and replace

Did that already....

I decided to test for stray voltage in the aquarium and I have close to 40v in the tank.....

.....My return pump is putting out about 11v, Heater about 4v, reactor pump 9v, Skimmer about 9v. Scary part, it's all brand new equipment (well, 6mos old)....

....When I turn off all the equipment, but leave the Apex EB8 (where all the equipment is connected) plugged in, there is a stray 11v in the tank. When I unplug the EB8, the voltage drops to 0

40 volts of "induced" current is kind of normal and I would do nothing.
It is actually induced voltage, not current.
(Electrician 40 years)

Thanks. So you don't think that could be a cause of my SPS not doing well? What's the difference between "induced" and "current"? Can my multimeter test for current as opposed to voltage?

 

[Kayo2289]

To test for current put the multimeter to check for amperage instead of voltage.. Whatever the multimeter reads will be in amperage or current flow..

 

[Jgoal55]

If I tested that right it's reading .02 mA.

I did it two ways and both ways read same result:

First, I inserted the neg (COM) probe into the ground of an outled and the pos probe into water (same way I measured voltage)

Second, I inserted both probes into water.

Both ways had same result.

I tried looking for ways to measure amperage using the multimeter but all results I found lead to testing amperage in a circuit by breaking the circuit and the reconnbecting it using the multimeter. I'm not sure how to do that in a reef tank. Lol

 

[Paul B]

So you don't think that could be a cause of my SPS not doing well? What's the difference between "induced" and "current"? Can my multimeter test for current as opposed to voltage?

My tank sometimes reads 60 volts, my SPS are all fine and they are mostly 8 or more years old. Anytime you put AC voltage near water such as heaters and pumps, voltage will be generated. If you hold the powerhead, it will induce that voltage in you. Unless it is 110 volts, forget about it. Induced voltage is the voltage that gets introduced into the water by just being in the magnetic field of an electrical appliance. All appliances make magnetism, and magnetism induces or makes a slight voltage in a conductor which is your water. That is how a transformer works. Your ground probe will direct that slight voltage to ground. Current is different. Current is also induced but in a tank it is so slight that you don't have to worry about it. Some feel that it has some affect and may cause HLLE (disease) in fish but it has never been proved.
40 volts of induced voltage is fine

 

[Jgoal55]

Thanks Paul. That clears it up.

I wonder if I have my grounding probe connected correctly? The one I purchased came with a metal disc on the end (not a plug with only a ground). I took that metal disc and screwed it into the center screw of the outlet cover. That said, it slight corroded that screw and disc.

Also, does water volume matter? You say you have 60v but in 100g; mine is only 38g.

Btw, congrats on a long run with a reef tank. Est. 1971 is impressive!

 

[Paul B]

No water volume in a closed system does not matter

 

[Jgoal55]

Thanks. What about the way I have my grounding probe connected? Is that ok?

 

[Paul B]

The center screw on an outlet is supposed to be grounded, and it is as long as that outlet is connected correctly. If it is corroding, it is probably connected correctly. It is easy to test with a cheap voltmeter.

 

[ERivera65]

ReeferGil on youtube just posted a video about this and he used GFCI plugs he bought at home depot and explains a bit about them and their function.

http://www.youtube.com/watch?v=tUh-ENey_PY

 

[Jgoal55]

thanks. that was a pretty cool video. Very cool idea to use separate GFCIs.

However, it talks mostly about GFCI and not so much about whether or not stray voltage actually affects livestock.

But, hey, I kind of trust a 40yr electrician...lol with 40 years reefkeeping experience!

If I tested that right it's reading .02 mA.

I did it two ways and both ways read same result:

First, I inserted the neg (COM) probe into the ground of an outled and the pos probe into water (same way I measured voltage)

Second, I inserted both probes into water.

Both ways had same result.

I tried looking for ways to measure amperage using the multimeter but all results I found lead to testing amperage in a circuit by breaking the circuit and the reconnbecting it using the multimeter. I'm not sure how to do that in a reef tank. Lol

Paul, do you think I tested the current correctly?

 

[Paul B]

You tested for induced voltage correctly. It is hard to get an accurate current reading when testing for induced current especially with a cheap meter but anything under 110 volts would be induced and is in everyone's tank, if it is not, they are not testing correctly or don't have any pumps or heaters in the tank. Any AC device in the water will induce a voltage and that has never been proven to affect anything negatively.
It may be hazardous to marine life but it has never been proven to cause anything.
It's alomst like the radiation from cell phones, it is all around us but do you know anyone with 3 eyes or 2 heads? As long as you have a ground probe in there, don't worry about it. Some people feel that doing without a ground probe is better because there is no current flow but that is a matter of debate and there are great tanks with and without ground probes. I personally never heard the corals complain.
If you have ever been to the tropics in a typhoon you will see plenty of lightning going into the water just over the corals. That happens every day and the corals are still there. If lightning hits the sea in Bora Bora, you can test it here. But you may need very long test leads. :lol:

 

[Jgoal55]

Yup, I see your points. Makes sense imo.

 

[unitedbga]

I bought 2 used hydor koralia circulation pumps on ebay to increase my flow. I plugged them and and put one hand in the tank to adjust them. I got knocked on my butt. I unplugged both of them and went upstairs. I did some research on how to test for stray voltage. With the used hydor pumps off and everything else on (3 heaters, 2 other hydors, aqua euro pump) I was getting just under a .5 volts a/c. I plugged in one of them and it went up to .6 Then plugged the other one in and it hit 120 Volts! Holy Crap!
I have a reefkeeper light controller and repeated this. That one koralia made my meter read 120 volts everytime it went on. I will now test for stray voltage

 

[Paul B]

That is not stray voltage, that is line voltage. Throw the thing out