Electricity And Water.

[tribalbrit]

So I was messing in the tank the other day and caught my wet arm on the overhead light unit and got a shock off of it. I spoke to an electrician friend of mine and he came today and checked it out.
There is no problem with the lighting unit as first thought however, and this is the funny bit (not) When the water was tested there was a live current present,
Now in the actual tank are 3 koralia pumps, and 2 power heads. When turning these off one by one the current dropped by 5 or 6 volts each time.
Meaning that each item is leaking power into the actual tank.

Has anyone else had this problem? If so how do you stop it happening?

I know you are supposed to switch everything off before sticking your hands in but I'm sure we are all guilty of not doing especially if we are just doing a quick tidy up.

If you add it up there is approximately 30 volts of electricity in my water, I will now switch everything off before sticking my hands in there.
This is only a problem if I touch the light unit while my hands are in the water, thus earthing the tank water.

 

[nurglespuss]

Yes I have the same problem too, turn of power before maintainance.

 

[Akasha72]

omg! I've always got my arm in the tank with the power on! ... and thinking about it my Dad is always telling me not to do it

 

[tribalbrit]

that's a bit of a relief but you would think that these pumps etc. Especially the Koralia's which aren't cheep would be properly insulated.'

omg! I've always got my arm in the tank with the power on! ... and thinking about it my Dad is always telling me not to do it

Me too. NOT anymore though.

 

[StandbySetting]

Are you sure it's not static charge? The pumps are probably fully insulated, but whenever you get a magnet which is moving in an electric field as is the case with motors, a current is induced which could be why you're getting readings off the tank.

 

[ainsy]

Wear a pair of wellies before putting you hand in the tank!

But seriously - this can happen - I used to find it quite a bit when my tank was full of salt water. None of the equipment was faulty however it seems that 'things that spin' ie. the impeller in your pump can generate a static electricity in the tank which earths when you put your hand in.

(It could also be cause by faulty equipment though - if you are unsure unplug!)

 

[tribalbrit]

Are you sure it's not static charge? The pumps are properly insulated, but whenever you get a magnet which is moving in an electric field as is the case with motors, a current is induced which could be why you're getting readings off the tank.

Had the volt meter in there and it was reading between 30 and 36 volts. The lethal dose is 50 volts. Bit to close for comfort.

 

[StandbySetting]

Where did you get the lethal dose thing from? Volts is potential difference, it's amps (current) that kill you, I've had 50,000V travel through me via a vandograph generator on numerous occasions and I'm still here to tell the tale!

 

[tribalbrit]

Where did you get the lethal dose thing from? Volts is potential difference, it's amps (current) that kill you, I've had 50,000V travel through me via a vandograph generator on numerous occasions and I'm still here to tell the tale!

Amps, volts, nuclear fallout. I don't want it in my tank.
I can't remember what the electrician said (its an age thing) but what ever it was it was above what is recommended for safety reasons.

And it b****y well hurt when it got me.

 

[StandbySetting]

My money is on static charge, which can be very painful but it is harmless.

Out of interest how did he find the voltage of the tank? I presume he grounded the volt meter with a plug socket and then put the other probe in the tank?

 

[tribalbrit]

Hope so, thanks!

My money is on static charge, which can be very painful but it is harmless.

Out of interest how did he find the voltage of the tank? I presume he grounded the volt meter with a plug socket and then put the other probe in the tank?

grounded it via the light unit.

 

[tribalbrit]

My money is on static charge, which can be very painful but it is harmless.

Out of interest how did he find the voltage of the tank? I presume he grounded the volt meter with a plug socket and then put the other probe in the tank?

Being told that static occurs in dry insulators and water is neither.?

 

[Vin Swords]

I think it static too.. Just wondering what kinda tester you guys used.. Ps.. I work As electrician.

 

[steve1]

as above it's current that is the killer not Volts ive had umpteen shock's off a HT lead on a car at work which is over 20kvolts per a lead and im still hear

do an ohms test see how many ohms are there then you will know how much current is actually running through the water

 

[Vin Swords]

Are you sure it's not static charge? The pumps are properly insulated, but whenever you get a magnet which is moving in an electric field as is the case with motors, a current is induced which could be why you're getting readings off the tank.

Had the volt meter in there and it was reading between 30 and 36 volts. The lethal dose is 50 volts. Bit to close for comfort.

Volts don't kill you but amps will. Just 0.2 amp is enough to do the job in wet conditions. In other words if your heater broken in the tank and if you don't have MCB protected, u will go to fish heaven.