stray current(ouch!)

I am getting a stray current from every device that is in my aquirum. is this normal?

each item is leaking about 2 volts and some are leaking upwards of 4 volts for a total  of 24.98 volts ac, I am measuring this with a fluke 87 true rms meter.

one probe in the water and one on a ground point.

what started all of this was with a few scrapes on my right hand I could feel the current this morning when I placed my hand in the tank, my left hand with no cuts could'nt feel anything.


so what is a "normal" voltage. My feeling is that there should be none. but with every powerhead leaking a small amount of current,  and all of them less than 6 months old.


Brian

yes, I agree and am looking for one now, but is this a "normal" amount from these devices?

it's not like i can stick a copper wire in the tank .


also I have a gfci that is still stitting in it's box, (going into the wall before my hands go into the water)

but with this much current it's probably going to trip, the gfci will not prevent shocks, it is only measuring for current that is different from ground to neutral.

I am measuring a difference between grounds, if I remember correctly.


Brian


Edited by bbeck4x4

I don't know if this will be helpful or not.  I didn't re-read the whole thread, but here is a fairly recent thread on the same subject.  Thought it might come in handy anyway.

http://www.utahreefs.com/forum/forum_posts.asp?TID=4865& KW=stray+current

Good article, I also have a electronic balast, and a ungrounded reflector, so while I have the soldering iron and heatshrink out( had way to many wirenuts with electrical tape)  i'll ground that to.


Brian

what I have read(very little on this subject so far)is that the magnetic fields from the lights will produce a current? or voltage? in the water.

same with me, as far as the wood hood. but with the reflector grounded the voltage drops on the meter from 25 volts ac to 9 volts ac.

this is a voltage not a current.

25 volts ac is somthing that I can only feel with a cut on the hand, less resistance into the body I guess, 9 volts well, who knows, of course these voltages are with the heaters unpluged, and only the lights on, with the mag3 on(return from sump) and a rio 800(which is driving the squid). I have not tested with the other two powerheads on.

another question is do I really need those other powerheads. looks like the rio is at 200gph and the mag3 with 4' of head is near 300 gph. Is that enough for a 40 gallon tank?

Brian

20-40 volts is not stray, it is normal ground differential. There is a natural voltage in the earth. All tanks show it. Also, the AC current creates a dynamic induction field around the wires and electical units themselves, which goes nowhere and bothers nothing until it finds a way out. Your finger. The cut was hyper-sensitive to a static voltage that is no problem.

If you use a grounding probe (~$10) you must also install that GFCI, other wise a defective powerhead or heater will continue to send electricity through the water to the probe and fry things good. I've seen a feather duster that looked like hair that's been singed with fire and Xenia that looked like it had been burned.

The reason for grounding a reflector is not for the tank, it's so you don't get shocked when you touch it. Whether it be the natural static buzz from induction or an actual fault/short.

Hope this helps.

Hey, guys, remember when Walt Smith was talking about actually adding
current to make the corals grow faster? He had pics of a metal structure
that electricty was wired to and then documented how fast the corals
grew.

I can't see doing that to a tank with fish in it, but maybe a frag tank?

Weird?

Mark Peterson wrote: The reason for grounding a reflector is not for the tank, it's so you don't get shocked when you touch it. Whether it be the natural static buzz from induction or an actual fault/short.

How do you ground the reflector?

Marks explaination was excellent!

Remember, normally, it is not the voltage that will kill you or your fish, it is the current!  The exception being extremely high voltage! (100,000 volts or more)

If you consider electricity to be the water in a water hose, voltage is just the pressure that the water has, the size of the hose and the amount of water flowing is the current.  You won't drown from the pressure of the water, but you will from the amount!

If you have a UPS on your system, be sure to put the GFCI between the UPS and your pumps, etc.  For instance, do NOT put a GFCI in the wall, plug a UPS into the GFCI and expect to be protected!

You can make your own grounding probes, however, unless you have some titanium just sitting around, it is just about as cheap to just buy one from a LFS.