Stray Voltage 90V and no damaged equipments

[reefpizza]

This is a really strange situation:
I have 90V AC between my tank/sump water and the earth of my circuit/house.
I have unplugged one by one each device with only minimal losses in voltage (2/3v each) for magnetic induction i guess.
But the 90v (they are a lot!) still there util i unplug the last plug (any "last plug" do the same thing) from the multi socket holder (already tryed to change that with no improvements).
Any idea what's going on?!

 

[elysics]

Where are you measuring earth? And does the same happen if you plug a single thing into a regular wall outlet, no socket holder?

 

[reefpizza]

Same multi socket or different plug in the same room give same results of 90v
I have not tryed to ground from water to see if i have current for the fish i'm a bit worried

 

[elysics]

So you stick one probe into the water, and the other where?

 

[reefpizza]

So you stick one probe into the water, and the other where?

In the ground pin of another free socket

 

[elysics]

What happens if you instead measure between the water and the metal of a running sink it you can reach that?

 

[reefpizza]

What happens if you instead measure between the water and the metal of a running sink it you can reach that?

I'll give it a try asap (maybe using a long piece of cable) so you wonder that something with my ground line is not correct?

 

[elysics]

Yeah, that'd be my first guess

 

[reefpizza]

Hopefully i have not have take any shock in this house to my self yet. (good thing if ground is not ok)

 

[reefpizza]

Yeah, that'd be my first guess

Tested, same result 90V between ground/pipe also i tried with an analog tester (in theory it must don't read an inducted voltage) i have no more ideas.

 

[elysics]

So to recap, you get the >90V reading no matter which device is the only one plugged in, and no reading if no device in, on, or under the tank is plugged in at all? Or no reading with some other stuff plugged in, just not in the power bar? And ground seems to work correctly?

What happens if you take one of those devices that give you a reading and put it on a bucket with saltwater, maybe in a different room, and measure there?

 

[reefpizza]

So to recap, you get the >90V reading no matter which device is the only one plugged in, and no reading if no device in, on, or under the tank is plugged in at all? Or no reading with some other stuff plugged in, just not in the power bar? And ground seems to work correctly?

What happens if you take one of those devices that give you a reading and put it on a bucket with saltwater, maybe in a different room, and measure there?

I'll give it a try, some dark magic is happening here

 

[homer1475]

At 90V you would get a significant shock when sticking your hands in the water.

Are you sure its not 90mV? Which would not be a concern one bit, and would just be induced voltage from motors being in the water.

 

[reefpizza]

At 90V you would get a significant shock when sticking your hands in the water.

Are you sure its not 90mV? Which would not be a concern one bit, and would just be induced voltage from motors being in the water.

90 solid v not mv also i have wood/plastic floor so i'm always isolated from ground when i put my hand in.

 

[homer1475]

Have you tried a different power strip, or plugging equipment directly into the wall and not using a power strip, or multi plug as you described?

beginning to think this may be an issue with the ground on the power strip.

 

[reefpizza]

Have you tried a different power strip, or plugging equipment directly into the wall and not using a power strip, or multi plug as you described?

beginning to think this may be an issue with the ground on the power strip.

Yup i have changed power strip and same result, i then have other 2 power stip connected to the first one, but if i remove both the voltage stay there

 

[elysics]

Yup i have changed power strip and same result, i then have other 2 power stip connected to the first one, but if i remove both the voltage stay there

Didn't you say you tried with no powerstrip at all? If not, definitely try that

 

[reefpizza]

Didn't you say you tried with no powerstrip at all? If not, definitely try that

if i remove the power strip i can connect only 1 device lol
I'm thinking about the switch that i have on every power strip... and the position of every ac cable between them

 

[homer1475]

Remove the power strip for now. Use just a single plug extension cord and plug 1 device in at a time. Measure voltage for each piece. If nothing is out of the ordinary, it's the power strip.

I still think it's probably a faulty ground in one of the power strips. Just because they have 3 prongs, doesn't mean they are grounded properly(specially if they are of the cheap kind).

 

[homer1475]

Yup i have changed power strip and same result, i then have other 2 power stip connected to the first one, but if i remove both the voltage stay there

This tells me right here that the first one, the other 2 are plugged into is probably at fault.