Stray Voltage

[dugg]

Well, during all of my recent fun, i recieved a slight shock from my sump and ran i few tests on my electrical parts to find out where the problem was. I found out a few things that i never knew before. Almost every piece of electrical equipement in my tank puts some voltage into the system. Using a volt meter, the results were-

Mag 7 = 8.5 V

Seio M620= 4.8 V

Heater = 0 V

New MJ1200 = 9 V

2 year old MJ1200 = 14 V

12+ year old MJ1200 = 38 V

After this little test, i am now finally going to install a titianium grounding probe. I never realized that even new equipement was putting current into the water before. I'm suprised my fish don't glow in the dark lol.

 

[zoomfish1]

I've realized the jolt from time to time also. I wonder what effect that has on our livestock/corals.

I am also ordering a grounding probe.

 

[dugg]

The info i have found, says that it causes lateral line disease and a few other known problems in fish. No idea what it might be doing to the inverts if anything. I know for me it causes sudden awareness of ones surroundings lol. When there is only around 15 volts in the water, you can't feel anything. When it is 38 volts it has a bit of a tingle or sting. I have broken a heater before while my arm was in the tank, and that hurt, so i would say the damage to the livestock would be relative to the amount of current too.

 

[eddybabyhd]

do you ground one side of the amprobe to the ground in the sockect then place the other in the tank? Is that how you get an accurate reading?

 

[dugg]

I used a volt meter. I switched it to volts a/c , then placed the positive lead in the tank, and (don't tell the wife) poured water on the floor for a good ground, and placed the ground lead in the water on the floor lol. Any solid ground will work, but i am not all about sticking things in water and sockets at the same time lol. I haven't had the wall socket apart, and you just never know how the last idiot wired something up. I will find that out when i get to wire my probe in. I bought the one that wires in direct to the ground rather then one with a plug on it.

 

[zoomfish1]

I guess what I felt was the tingle. Where did you order yoursm from?

 

[dugg]

Dr. Foster's , it was $16.99 i believe.

 

[chris4693]

Accually what you are feeling is Current/Amps, not Voltage. At work I get to play with 4160 Volt lines, luckly there is Zero Amps of current on them at the time. On a 30 volt source with 2 Amps of current you might as well kiss life good bye, the higher the voltage this less and less amount of Amps it takes to kill you.

I would check to make sure all of your pumps and such are grounded properly. I have less then 1 volt of AC in my water.
Unless you are using devices that do not have a grounding wire you should have close to Zero Vac.

Although I did feel a little tingle in my tank today while moving rocks, kinda spooked me, found my thumb covered in little bristles. Dang Worms!!!

 

[eddybabyhd]

so i didnt think the water on the floor would be an adequate ground. Chris can you confirm this to be adequate. I just had never heard of anything like this

 

[jjmg]

I've always been a bit confused about the stray voltage in a tank. As I understand it electricity follows the most direct path to ground. I can't imagine an ungrounded piece of equipment built for fish tanks. So if your tank is sitting on a wood stand, I would guess the stand is dry and nonconductive. Why doesn't the stray voltage follow the most direct path right back out to ground with the grounding features of the item?

Now if you put a grounding probe into your tank and give the electrons a better path to ground your asking for trouble. Much the same as putting water on the ground and using that to test to.

I can also understand if your standing on concrete and the tank is on a wood stand and you stick your hand in the tank you may feel a bit of a current since your supplying a ground. My wood floors on brick pillars don't offer any ground.

But if you keep your hand out of the tank won't the current follow the most direct path and exit the tank before it really enters?

 

[eddybabyhd]

so my voltmeter on the 200 ACV setting reads 1.5 and jumps to 2.7 if the heater controller is turned off, the heater is on right now.

 

[dugg]

I tested the current in the water with each individual piece of equipment. Even my Mag7 wich is only about a month or so old, and has a grounded plug was putting out 8.5 volts. My house was built in 1957, and has been built on to atleast twice since. The part that the tank is in, is the original house, and has 1957 electric, so i would venture to say that the grounding isn't all that great on my electric lol.

The water on the floor isn't the best ground, but it will do for my purposes.

 

[dugg]

My floor is a concrete slab, and here in Florida the ground water is like 2 grains of sand under the surface, so the wet slab does make a pretty decent ground.

The tanks water can't naturally ground, because glass is an insulator, and cannot conduct electricity.

 

[dugg]

Your volt meter should have a section with VAC and VDC. That is where it should be set to test VAC.

 

[jjmg]

As you said the tanks can't natrually ground. I'm in Fl also and have a basement. So why are you so worried about tests that don't tell the truth? But you can buy more stuff!

 

[Russ Braaten]

If you use a grounding probe you will assure that your tank and inhabitants will have electricity go through them.

Ever watch squirrels run power lines? Hook a grounding probe to the squirrels tail and KABLEWY!!! Zapped squirrel.

Your lights have potential energy going to them, make a ground by flipping the switch and you get light. If you add a grounding probe you make the switch connection.

The only time a grounding probe may be used is for your safety. If you have wet feet on a wet floor and you plan to stick your hand in the tank with bad wiring, then stick the probe in before you stick in your hand. Then remove the probe after you are done grounding the tank with your body.

 

[eddybabyhd]

I heard a similar talk about the grounding probes. If the tank is not grounded, as mentioned about. Then the habitants wont react as if they have a grounding probe stuck in the tank. Then the current is passing through the water to the ground.

 

[dugg]

Here are my current readings, the first is the volts AC, the second is amps.

 

[chris4693]

Not sure on how good the floor being a ground is, never thought about testing it. Best way is to drop Pos lead into the water and stick your Common lead into a the Ground part of your plug.

Voltage is potential difference. Lets say the Voltage or potential difference of two wires is 10 volts. This means that one wire could have 5 volts applied to it and the other would have either -5 or 15 volts applied, giving a potential difference of 10. Now then Volts is not what give the shock. Shock happens when you have a flow of electrons moving from the lower or Negative source to the Higher or Positive source of applied voltage.

With that being said, the reason you would get shocked by your water is the potential difference between something else you are touching or standing on and your tank water. Also since your fish and corals are in the water and not touching anything else there would be no potential difference and would not effect them in any way.

I have a 9.5 mag over a year old, 2 newer Seio's, and a MJ well over 5 years old and I read less then 1 volt of potential difference between my water and the ground of my house. If you are testing your Vac and get a couple of volts then I would ignore it. If you are getting shocked and are testing a higher amount of Volts then you have a problem that would cause me to find the source and fix it if possible.

Just remember all it takes is 30 Volts with 8 Amps of current to kill you. Less then 8 Amps on a 30 Volt potential can stop your heart.
This does not mean less then a 30 volt potential won't kill you, if you have enouph current(Amps) you can still get seriously hurt.

I work with Electricity everyday, I have been shocked only once. 720 Volts and MilliAmps will knock you on your butt and doesn't feel to good. Safety is number one with Electricity, if you are going to be testing anything be sure not to ground yourself and keep your hands on the leads of your meter and not on the equipment.

Oh and wood is a conductor, a very poor one but it is a conductor. Very Very dry wood would only carry a very minimal current if any. The more moisture it has the better a conductor it becomes. I think all of our tanks have an evaperation rate, your wood isn't as dry as you would think.

 

[chris4693]

Your lights have potential energy going to them, make a ground by flipping the switch and you get light. If you add a grounding probe you make the switch connection.

When you flip a switch you are connecting one wire to another wire with a potential difference of 120Vac. The third wire connected to the switch is the ground wire.

I will do a little digging in my reference at work tomorrow before I explain the ground probe. I believe I know but don't want to make a statement and be wrong.