grounding probe?

[LEM504]

About the electrical stuff. First of all you will have to know - that I understand that the wide prong has to go into the big hole. Not much more! I have fixed a few things, and strung a few wires. To my amazement it worked!

What we need is an electrician’s expertise - anyone out there?

It is not uncommon, for someone to drive a nail or screw into a wall, and clip a wire.
Everything will work, and no one will know it is there, until it gets damp, or someone gets between it and a ground.

A friend who happens to be an electrician installed a large sign, with a blinking light, on a freeway. Specifications, stated that the light had to blink so many times a minute.
It worked, but the blink rate was several times faster than specified. Wouldn’t pass.
Several components were replaced, but the problem remained.
None of the old experts could figure it out.
He noticed an old house a few hundred feet away, and checked the service to the house.
He discovered the house had defective wiring and it was feeding power into the ground.
The ground was wet, and it was interfering with the power to the sign.
When he turned the power off to the house, the sign worked perfectly.

Don’t know how they corrected the problem, but they fixed it.

I guess my point is - these things are not always as simple as they appear.

My Mother-in-laws house developed a nasty habit of giving people a light shock from time to time, at the faucets. Trouble shooting found no problems, so we assumed the problem ( wild guess ), was in the water heater. We replaced it, and the problems went away. Nothing beats blind luck!


OK Checked my tanks.
Two 50 gallons tanks. Heaters, box filters. Both tanks read zero. Both tanks have suspended lighting. Light fixtures do not touch the tanks in any way.

Two display tanks. Power heads, box filters, heaters, fluorescent light fixtures.
Light fixtures are resting on top of the tanks, with glass between the fixture and tank.

One tank measured 0.1 volts from the water in the tank, to the ground ( third wire )
Other tank measured 0.3 volts.

Try unplugging your light fixtures, and see if that makes a difference. It could be a weak ground of the light fixtures, caused by dampness.

Is it possible that your meter is not in the correct mode, and is measuring the resistance In the copper ground rod?

Larry

[LEM504]

Here is X Ray - computer experts opinion --

Hi Larry - I took a look at the discussion and it seems that what they're doing is
pretty much a waste of effort unless you want your GFI (Ground Fault Interrupter) to
trip when there's a fault to the fish tank. Even if there IS a fault, it won't hurt the fish
unless you start conducting current across the tank. The voltage the guy is
measuring is due to capacitive coupling that will happen even with perfect electrical
insulation. The meter he is using draws so little current that it will indicate voltage
with the probes connected to nothing. The joke about GFI's is not having one when
you hairdryer falls into the bath tub. Both the three wire and 2 wire units do what
they're supposed to do - they cut off the current when current gets bypassed to
ground (thru your body, for example) (if your house is wired correctly!). Later.

Bob


On 3 Feb 2004 at 6:40, wrote:

>
> Bob,
> You are into electrical goodies. Next time you have a few minutes, take a look at this thread,
> and see if you can make heads or tails of it.
> It all started by someone making a comment about stray voltage in aquariums. ( heaters,
> pumps, and other do=dads, are in direct contact, in the water, and all are powered by 110 volt
> AC.) No one understands what the hell is going on, or even how to check for it.
>
> I was also informed by friend, that Ground Fault Receptacles, are pretty much a joke. ???????
>
> http://forum.simplydiscus.com//index...threadid=16055
>
> Thanks,
>
> Larry
>

[slicksta]

I agree with some of his statement but not all...
Yes the voltage is harmless...there is no way for the fish to get between the voltage and ground.
But the meter reading changes for each appliance plugged in.... so it must be reading something.
Now whether or not this is the correct meter to test this....I am not sure. It may be the measurements are exaggerated.
Also whether or not you use a ground probe, if there is a harmful voltage leak the GFI should trip.
Is this a waste of time.....probably....I only did it as an experiment after seeing the post and would never pay the $20 bucks or so for a LFS probe.

[slicksta]

in reading your first post on page 2....I would check the water meter bond on your service...it must be non-existant.
If your water heater is leaking voltage to copper pipes it should go to earth at the service where your electrical system and water meter are bonded. Electricity will take the easiest path and for you to be a better path to earth.....you must have been the only path. Replacing the heater fixed the problem but you may still have a dangerous situation.

....ohhhh wait....I just reread your post.....you said Mother In-Law.....never mind..... ;D

[ronrca]

First,

I didn't think it would be a problem since all the water lines in my house are made of copper????

You are correct however the water lines in your house get used on a consistant bases therefore get 'flushed' out. Also and perhaps more importantly is that air is also involved in your tank where this is not the case inside your water lines. Its the same story as rotting. It you were to submerge driftwood and never let it be exposed to air, it will not rot as far as I know. Same scenerio with the copper in the tank. In any event, just a word of caution is all (particularly in saltwater).

Second, when measuring the voltage that you mentioned (is that V or mV), what are you really measuring? Basicly a potential between the tank and ground. What does it mean? Nothing really and it does happen all the time. Why does it occur with each hardware plugged in? Magnetic fields, static charge, etc! If you have a GFI then it will trip if a fault were to happen.

You can use a ground probe but make sure its not connected to a ground that is also connected to the same ground that goes thru the GFI. You need to connect it to a 'separate' ground or a ground before the GFI (looking from the panel down stream).

One more thing,

It may be that these devices are actually generating a voltage

Where there is a voltage 'being' generated, all you need to do is complete the circuit and you will have current flowing. This can be done by you, which I never hope, touching the water or by a ground probe (especially dangerous without a GFI) as the circuit is complete to ground. Imo, Id let the GFI worry about 'leakage' current as it will trip much faster than I can blink!

Please read the following article:
http://forum.simplydiscus.com//index...threadid=14713

Capactive coupling? Hmmmm! Very interesting thought! Thanks!

[slicksta]

Again I agree with most of what you said....
The probe was grounded after the GFI and the GFI did not trip.
IMO then the voltage has to be generated. The fact that it does not trip the GFI leads me to believe this. If it were a "leaked voltage" then there would be a unbalance between hot and neutral and this would cause a trip. I can see the two pumps creating a voltage since they are an inductive load....but since the heaters are resistive loads....that has me scratching my head ???
As you can see in the pic it is measuring V~ not mV~.The Fluke is an auto-ranging model.
Again I do not believe this to be a problem in any way......just very interesting......
Does dissipating the voltage to ground aid in the health of your fish....who knows....The people selling ground probes will tell you yes.
Would I buy a house next to a sub station.....probably not....
As far as the copper leaching...not sure...as far as oxidation at the water line.....that I would agree .....probably why probes are stainless or titanium.
Again this was all an experiment....the copper was a temp just to see if it would work.

[LEM504]

After watching this thread for a few days, I had to step back and look at the whole picture.
After a look at the pile of plastic pipe fittings next to the breeding tanks, and all of the junk in the cabinets under the display tanks, I had to ask myself, “Just what is it you are trying to do?”

The fish are beautiful, and a challenge, both at just keeping them alive, and breeding.

Why do you have all of this junk? Over the years, I have built tanks from scrap glass, plywood and you name it. The list of homemade filters is endless. I have wasted months of my life, trying to figure out a way to make water run up hill.

Some of the contraptions worked, but most, not as well, as the ones I bought. All of the homemade stuff cost more, than the factory stuff. ( Except the tanks made of scrap glass. If I could get the bleeding stopped without going to the Emergency Room, they were cheaper. )

At the bottom line - I like the fish, and their challenge. Maybe I’m into this, just to re-invent the wheel, and make the water defy gravity!

It is comforting to see that I have lots of company!
;D ;D

Larry

By the way - That new pump should deliver in the morning. I ain’t done with the gravity thing!!

[slicksta]

........and that was what I was doing....just trying to keep busy on a cold NE day....
I have to admit I am very proud of my DIY wet/dry filter and circulating water system around my external pump to keep it cool and heat my tank water... ;D

[ronrca]

I love the diy projects especially seeing what other people are doing, then imprivising and building it myself to fit my needs.

IMO then the voltage has to be generated

The article that I mentioned previous does try to explain the voltage that you may be measuring. Not only do motors, conductors create magnetic fields, there are magnetic fields that exist in nature. This may also have an effect on ungrounded systems. Just another thought!