MH Putting electric current in the water

[james37128]

So today just after returning from the LFS with some new polyps and xenia i stuck my hand in the tank and could feel a small shock at my fingertips. First thing i thought is powerheads, unplugged them, put my hand back in the water. Nope not the powerhead, individually unplugging everything one by one i found it was the MH. But, how could this be? There are no wires or anything running into the water, nothing. So finally i took it off the tank. No more shocks... So then finally i decided to put some electrical tape around where the metal wire hangs on the support, put it back up and now no problems. BUT if i decide to get my hands wet and for some reason touch the light, another shock comes my way. so somehow the light fixture sent a current through the wires down the metal support, and somehow through the moisture of the side of the tank down into the water. Has anyone had this sort of thing happen? If yes, what did you do to fix it?

[PSam]

Sounds like bad ballast (?). I would take it off the tank - that electrical tape is not a good fix.

[FishTruck]

The self test shock method... I love it. Dangerous as he>>, but, I have resorted to this as well.

Who knows a safer way to find the offending device, rather than sticking your hand in and seeing if you get shocked!

RGM

[xtm]

Your MH fixture is not grounded properly and/or salt creep or moisture must have seeped in the ballast or fixture. Take the fixture apart and clean it thoroughly. Make sure your metal fixture is grounded through the third prong of your socket. Also check for spliced wires touching the metal enclosure.

Be VERY cautious. If you don't know much about this, I suggest you take the whole lighting to a qualified electrician.

[xtm]

<a href=showthread.php?s=&postid=10909295#post10909295 target=_blank>Originally posted</a> by FishTruck

Who knows a safer way to find the offending device, rather than sticking your hand in and seeing if you get shocked!

RGM

Multimeter... Set range to 20 VAC. Put (+) probe on water and (-) probe on the third prong (GND)

My old no-name powerhead registers 10v so I took it out. Zero voltage after that.

Be very careful when doing this as electricity can kill you. Do so at your own risk

[trd47]

I agree with xtm about your light not being properly grounded. just a thought are you bare footed when you touch the lighting fixture? if you are trying wearing some rubber shoes or flip flops that should prevent the stray electricity from finding its way to the ground.

if you are wearing footwear disregard my reply about wearing foot wear.

[james37128]

How could i have looked past this. The ballast only plugs in with 2 prongs, it has a 3rd ground wire just hanging out of the plug. so where do i ground this out to?

[pogona]

You are going to have to re-wire your plugs to accommodate a grounded plug, this is a must when working around water.

Remember, As little as 10 microamps of current passing directly through the heart can cause ventricular fibrillation (heart muscle fibers beat out of sync, so no blood is pumped) and cardiac arrest.

[james37128]

I cant rewire the plug. it has a spare wire coming out with a little U shaped metal prong to screw it into a ground. But my problem is where can i screw in this as a ground? Its sorta like parts on your car, they usually have a ground wire coming off and you just screw it to the frame of your car and that grounds it out, but what would be a good thing to screw this into?

[oldreefer76]

I see you are in Japan are you running 110vac or 220vac? 60hz or 50hz electric? are your outlets 2 prong or 3? if they are three then you can attach the ground wire to the screw that holds the cover plate in place

[james37128]

Yes I am in japan but I am on an American military base so we use all american outlets/power and such. I cant remember 110/220 or 50/60, but its the same as most houses in the states. Which does bring a good point that the MH that I have is from Japan, which is probably the reason it only has the two prong plug with the ground cord hanging off, since houses outside the base only have the two prong outlets. It makes perfect sense now. I wonder if i am having a problem because the MH is supposed to run of either 50 or 60 Mhz instead of what we have here on base. But I will screw in the ground cord to the outlet plate and see if that works. Thanks a ton.

[pelochas]

the ballast is bad, you need to inspect the wiring
there should not be a continuity of power to anywhere but the lamp. if its leaking out to the harness or outside, thats why the ground is for. to protect. not to patch it up and to stop it from shocking you. so the ballast needs to be repaired or thrown away

[xtm]

Back in Asia, we use metal rods that go to the ground (earth) and attach the third wire there. You might have to manually do this if the third prong is not available.

But since you said that you are in an American base I assume you are using the American outlet (with large/small/third prongs?)

If so, you will have to buy this plug with 3 prongs (I've never seen this in Asia btw. but who knows, they might have one)
http://ec1.images-amazon.com/images/I/211YFRY6WCL._AA160_.jpg

You then need to designate the third wire (the "hanging" wire) into the third prong so you get a good ground.

[xtm]

However, this is just a safety feature. If you are getting a shock from your appliance, then something is shorted inside the fixture. You ABSOLUTELY need to take it apart and look for spliced wires, damaged and loose connections, bad terminals, etc. This is the source of shock to begin with.

[sabbath]

Sounds like the MH wires where inducing voltage to the tank. You know that electromagnet thing you made in school.... Moving the wires farther away from the water is a good idea. The lamp gets something like 600 volts to it so it has some pretty good eddy currents.
Yes ground everything good light, tank...