Is This Stray Voltage

[User]

What? Not you?


In response to me suggesting he stick a voltmeter in the water. Come on man.

Well, it won’t. Doesn’t mean I suggested your tip was trash.

Like I said, I’m done. You read whatever you wanted in that sentence and took exception to it. Wasn’t my intention, so I can’t defend what you think you saw.

 

[reeferfoxx]

Well, it won’t. Doesn’t mean I suggested your tip was trash.

Like I said, I’m done. You read whatever you wanted in that sentence and took exception to it. Wasn’t my intention, so I can’t defend what you think you saw.

We're good now.

I think if I were to see the misconception in my sentence, I would have agreed and taken it further. Sort of like, "yes, a voltmeter would be the proper device to detect stray voltage. If you weren't informed on how to use it, let me tell you."

Just be mindful. No worries overall.

 

[livingcolors]

OK, don't make me stop this car!

 

[livingcolors]

OK, don't make me stop this car!

 

[salty joe]

OK, don't make me stop this car!

LOL!

To the OP. Tingling on a scratch or cut is a pretty good indication of stray voltage. A great way to find the offending equipment is ground the tank water with a grounding probe. (a temporary grounding probe can be made from a titanium heater) Then, one by one plug your equipment into a GFI receptacle. Under those conditions, anything 'leaking electricity' will trip the GFI.

 

[PhreeByrd]

Tingling on a scratch or cut immersed in saltwater is completely normal, and is not any indication of stray voltage. A GFCI outlet is also not a good diagnostic tool at all. As others have said, get a multimeter, learn how to use it, and then check your tank water for voltage. You should read 0 volts (AC and DC) between the water and a known ground. If you read anything above zero, then you have one or more pieces of defective equipment.
Every home center has inexpensive multimeters available ($15 or less).
There are tons of YouTube videos that can help you learn to use the multimeter correctly.

 

[WVNed]

I have never had a tank that read 0 volts. There is always some induced voltage in a tank.

 

[salty joe]

Tingling on a scratch or cut immersed in saltwater is completely normal, and is not any indication of stray voltage. A GFCI outlet is also not a good diagnostic tool at all. .

Dead wrong on both counts.

OP's discomfort gets worse the more things are plugged in and goes away when shoes are on. I've experienced it and it sure sounds like stray voltage to me.

Plugging components one by one into a GFI while the tank water is grounded is an outstanding way to determine problematic equipment. It's dead simple and highly effective.

As far as getting a voltmeter and learning to use it, heck yes, they are handy for so many things. But a voltmeter is not needed to determine which piece or pieces of equipment is causing the problem.

 

[Todvod]

We're good now.

I think if I were to see the misconception in my sentence, I would have agreed and taken it further. Sort of like, "yes, a voltmeter would be the proper device to detect stray voltage. If you weren't informed on how to use it, let me tell you."

Just be mindful. No worries overall.

Yes. That’s the way to do it.

 

[PhreeByrd]

Dead wrong on both counts.

Think again.
And maybe a little more before you post a statement like that again.

Get a bowl of saltwater. Cut your finger. Place your cut finger into the bowl. Feel the tingle? It might be more than a tingle. It often stings. Sometimes it stings a lot... people have differing tolerances for pain. But there is no electricity involved at all. In case you've never heard the phrase "rubbing salt into a wound", this is not some new, rare phenomenon. Tingling of a cut/wound when placed in saltwater is most definitely not any indication of electricity being present, ever.

The shoes, yeah, that's a weird point, but it doesn't change the above at all, in any way.

As for a GFCI receptacle being an 'outstanding' method of testing for stray voltage, there are so many things wrong with this assertion that I can't even begin.

Just buy the VOM and be done with it.

 

[salty joe]

Yeah, you are right, I should have been more tactful. Sorry about that.
The feeling of getting an electric shock on wounds immersed in saltwater is unmistakable. I have felt it before. It's real.

But please. I never suggested a GFI as a test for stray voltage. I did highly recommend and absolutely do recommend using a GFI to find problematic equipment. Here's the deal-if the tank's water is grounded, when something that is 'leaking electricity' is plugged into a GFI, the GFI trips right now. It happens to be a simple, effective, quick method to find problematic equipment.

And heck yes, get a voltmeter and learn how to use it. They don't cost much and are an invaluable tool.

 

[WVNed]

Except is isn't stray voltage you have to worry about. Most tanks have some induced voltage in them.
What you test for with a meter is stray current.

 

[Mattrg02]

This is fun

It’s actually not voltage that is the problem, but the flow of charges particle that is the problem.

Voltage is a potential for these charged particles to flow. Doesn’t mean that they even can, depends on the conductor.

There is stray voltage literally everywhere. Get an EMF meter and walk around your house.

Power heads have electromagnetic fields within that will most definitely propagate through the tank. Doesn’t mean lethal current will flow through the tank though.

Btw-5mA will stop your heart. How much current will harm the tank livestock? Hard to quantity that one.

Use your DMM to measure the current from tank water to house ground.

Also, house ground may also be a problem if it isn’t up to spec anymore.

Edit: Be extremely careful sticking probes into the ground prong of your outlet. Mess up and you might die.

Btw-How many EEs in the House?

-Matt

 

[WVNed]

Old phone man. Used meters at the top of a telephone pole while it was raining at night.

 

[Brew12]

This is fun

It’s actually not voltage that is the problem, but the flow of charges particle that is the problem.

Voltage is a potential for these charged particles to flow. Doesn’t mean that they even can, depends on the conductor.

There is stray voltage literally everywhere. Get an EMF meter and walk around your house.

Power heads have electromagnetic fields within that will most definitely propagate through the tank. Doesn’t mean lethal current will flow through the tank though.

Btw-5mA will stop your heart. How much current will harm the tank livestock?

Use your DMM to measure the current from tank water to house ground.

Also, house ground may also be a problem if it isn’t up to spec anymore.

Edit: Be extremely careful sticking probes into the ground prong of your outlet. Mess up and you might die.

-Matt

This is fun.

Many people know the "bird on a wire" analogy. A bird sitting on a high voltage line will not get shocked because there is no path to ground. So why don't birds ever sit on 500kV or higher lines, why only the ones under 345kV?

Well, it has to do with ionization. At very high voltages the air begins to ionize and causes a prickling sensation on your skin. It can be very painful. This is why people who get dropped off on high voltage lines via helicopter wear corona suits which are made from a metal mesh. So is this a current issue, or a voltage issue?

Well, this is Reef2Reef and a marine tank discussion, so how does the bird analogy apply? Bottom line is that it doesn't. If someone tries to tell you that installing a ground probe will put a fish at risk because there is a path for current flow, they have no idea what they are talking about. They are missing one key point. The fish has a higher resistance than the salt water they live in. Since current has a preference for lower resistance more current will flow around a fish than through it. This is why you can only use electrofishing in fresh water. If you are a nerd like me, I show the math (here) behind why current isn't likely to be a problem with marine fish. A worst case 20A of fault current will only allow a maximum of 0.005A of current through a fish.

Which makes me wonder... could the voltage itself be an issue? Could the fish in our aquarium feel a tingling/prickling sensation from either fault or induced voltages? Could this be why some people feel there is a connection between HLLE and tank voltage? I have no idea, but I find it an interesting to think about. Just like a bird won't land on a high voltage line, should we protect our fish from even induced voltages by using a ground probe?


Food for thought!

 

[WVNed]

Completing the circuit with a ground probe does not make the voltage induced in the tank go away.

 

[Brew12]

Completing the circuit with a ground probe does not make the voltage induced in the tank go away.

The induction still happens, but the water will stay at ground potential instead of the higher induced potential.

 

[WVNed]

If you provide a voltage source multiple paths to ground what is the voltage across each one.
It is the same amount.
How much current each sees depends on the resistance of the path.

You point would be like saying a wire goes to ground so I can grab it because it is safe. I am pretty sure you know that isn't true.

As to the other part I once read that many fish have the ability to sense electromagnetic fields. It was theorized that stray voltages gave them something akin to motion sickness.

 

[Brew12]

If you provide a voltage source multiple paths to ground what is the voltage across each one.
It is the same amount.
How much current each sees depends on the resistance of the path.

Exactly. Which is why marine fish will see almost no current through them. They are a much higher resistance path.

You point would be like saying a wire goes to ground so I can grab it because it is safe. I am pretty sure you know that isn't true.

Hmm.. not sure how to answer this one. From the point that every wire "goes to ground" you are correct.

If we are talking only about wires with a low resistance to ground, I would disagree. We routinely use a wire to attach something to ground to make is safe. When we work on our 500kV and 35kV systems we routinely hang personal protective grounds to make it safe. The entire concept behind going from the old 2 prong style plugs to 3 prong plugs with a ground is because of this concept. That ground wire connects to the metal case of the tool to clamp its voltage to ground and make it safe in the event of an internal short from the hot leg to that metal case.
Now, can there be a time when even a low resistance connection isn't safe? Sure. We see this too. We can be 50 feet from our grounds in an area with a large amount of inductive sources and still draw an arc with a jumper cable. This phenomena occurs at high levels of induction and at high frequencies. It is not something you will see on a 120V, 60hz system limited to 20A. You let me bond a 400ft, 12AWG bare copper wire to ground, you can connect a 20A, 120V, 60hz source to it and I will bare hand it anywhere along the length standing on a copper sheet.

As to the other part I once read that many fish have the ability to sense electromagnetic fields. It was theorized that stray voltages gave them something akin to motion sickness.

I hadn't heard the motion sickness part, but I can see that making sense. I'm not sure 30V of induced is any different to a fish than 0V induced since they don't have a ground reference anyway. I wouldn't be surprised if voltage doesn't play a part at all and that the problems are because of frequency.

 

[WVNed]

In the case of fish I think it has more to do with the fields around the fish than any current flowing anywhere.

I was once in a house where the carrier had broken for the electric service and the ground outside for the service entrance was broken. I had to get some wire and make my own ground with a screwdriver in the dirt to fix their service. The outside of the stove was energized. All the loads in the house where working through some path to ground that wasn't obvious.

I trust my meter and nothing else when it comes to electricity. It is truly herding cats. Viscous ones that can bite you.