Stray voltage - help!

[Fishingandreefing]

Use a grounding probe.

I got hit one time by a broken UV lamp. Then hit again by a cheap powerhead in the sump. still haven’t installed the probe and I need to now that I’m reading this

lol

 

[n2585722]

Ok, I got home and checked in the sump and in the tank. The first reading was the sump 316 mv and the second was the tank 481 mv. Neither was anything significat. Probably just using the water as an antenna and picking up signals in the air.

 

[jmichaelh7]

Ok, I got home and checked in the sump and in the tank. The first reading was the sump 316 mv and the second was the tank 481 mv. Neither was anything significat. Probably just using the water as an antenna and picking up signals in the air.

How exactly are you checking for stray voltage. Placing what meter in the water

 

[n2585722]

How exactly are you checking for stray voltage. Placing what meter in the water

One probe in the water and the other in the ground of an AC outlet. The meter is just proped up aganst the outside glass of the tank. There is nothing electrical in the tank itself. It is all in the sump but the tank is a larger body of water.

 

[vetteguy53081]

Typical culprits are:
Powerheads
heater
Return pump
skimmer.

While not a solution, a ground probe is a must in reef tank

 

[Fishingandreefing]

Typical culprits are:
Powerheads
heater
Return pump
skimmer.

While not a solution, a ground probe is a must in reef tank

Yup those are the culprits and I got the ground probes plugged in.

I saw one member posted that at 20v is not something needs to be worry but I want to hear more from others to make me have a better peace of mind lol

 

[Fishingandreefing]

Ok, I got home and checked in the sump and in the tank. The first reading was the sump 316 mv and the second was the tank 481 mv. Neither was anything significat. Probably just using the water as an antenna and picking up signals in the air.

Don’t even know what voltage is that, not an electrician here

 

[vetteguy53081]

Don’t even know what voltage is that, not an electrician here

@Brew12

 

[n2585722]

Don’t even know what voltage is that, not an electrician here

316 mv is .316 volts. 481 mv is .481 volts. 1 mv is 1/1000 of a volt.

 

[Fishingandreefing]

316 mv is .316 volts. 481 mv is .481 volts. 1 mv is 1/1000 of a volt.

That’s a really low readings. It seems like everything I run in my tank carries about 1-5v thus the 15-20v range

 

[n2585722]

It could be the meter or the environment. Try grounding one probe and touch the other one and see what you are reading.

 

[Fishingandreefing]

So does plugging in the ground probe really helps the tank get rid of the stray voltage or just safe for me not getting zapped?

 

[n2585722]

So does plugging in the ground probe really helps the tank get rid of the stray voltage or just safe for me not getting zapped?

Only use a ground probe if you also use GFCI outlets or breakers with the equpment around the tank. The water is a semiconductor and will draw current to the ground probe if there is an actual leak. This would be dangerous without the GFCI circuit to stop the power if it does happen. I would not setup a tank without everything at the tank on a GFCI circuit.

 

[Fishingandreefing]

Only use a ground probe if you also use GFCI outlets or breakers with the equpment around the tank. The water is a semiconductor and will draw current to the ground probe if there is an actual leak. This would be dangerous without the GFCI circuit to stop the power if it does happen. I would not setup a tank without everything at the tank on a GFCI circuit.

But to answer my question, would the stray voltage dispersed by the ground probe I plugged in?

will get some GFCI soon. Would it be sufficient if I plug all the source to one GFCI?

 

[n2585722]

No the voltage would still be there if it is actually leaking from something submerged in the tank. It would just give it a ground point and current would flow between the leak and the ground probe. If you stick you hand in closer to the leaking device you would likely still get shocked. If you have GFCI it would trip and there would be no voltage or current flow if you have a ground probe. Without the probe there would not be any current flow till you stuck your hand in the tank and then it would trip. So it is good to have both. The only problem with using just one GFCI is if it trips you will loose all power. If you have two only the one with the offending device would trip and the other would continue to supply power to the devices it powers. That way you can split your flow pump etc between them.

 

[Fishingandreefing]

No the voltage would still be there if it is actually leaking from something submerged in the tank. It would just give it a ground point and current would flow between the leak and the ground probe. If you stick you hand in closer to the leaking device you would likely still get shocked. If you have GFCI it would trip and there would be no voltage or current flow if you have a ground probe. Without the probe there would not be any current flow till you stuck your hand in the tank and then it would trip. So it is good to have both. The only problem with using just one GFCI is if it trips you will loose all power. If you have two only the one with the offending device would trip and the other would continue to supply power to the devices it powers. That way you can split your flow pump etc between them.

At what voltage will the GFCI trip and shut off everything? It appears that each device carries at least a couple voltage, some higher some lower thus add together, I am having about 25. Again, my other tanks are about 15-17.

 

[Sebastiancrab]

Best thing to do is to take each piece of equipment out of the tank and put it in a bucket of water and test it. I got shocked a couple of months ago when my ground probe fell out of my tank. The GFCI did kick in.

 

[Fishingandreefing]

Best thing to do is to take each piece of equipment out of the tank and put it in a bucket of water and test it. I got shocked a couple of months ago when my ground probe fell out of my tank. The GFCI did kick in.

Already did. I shut off one by one, but somehow there’s still about 5v even though everything is shut but not unplugged. I will just leave them as it and will get some GFCI

 

[Fishingandreefing]

I am pretty sure everyone’s tank got some stray voltage and the more devices you plugged in there more you will get.

 

[n2585722]

At what voltage will the GFCI trip and shut off everything? It appears that each device carries at least a couple voltage, some higher some lower thus add together, I am having about 25. Again, my other tanks are about 15-17.

The GFCI is not tripped by voltage. What it does is compare the current in the hot side to the current in the neutral side. If the current in the hot side is more that the neutral then it will trip. If they don't match then at least some of the current flowed between hot and ground bypassing the neutral. The amount of current we are talking about is very small so any real leakage would trip it. Now induced voltages in the tank are different and will not cause the GFCI to trip. These are normally low and not an issue. Hope this helps explain how the GFCI works and the reason to use it with the ground probe.