Getting zapped occasionally- stray voltage?

vdubfiend · 08/30/2006, 02:27 AM

what is the best way to check this with a volt meter?
settings?
thanks!

jeffbrig · 08/30/2006, 07:36 AM

If you're getting zapped when you reach in to the water, there's no need to measure. Your hand has already confirmed voltage in the water.

I'd start unplugging equipment to isolate the cause. If you want to use a meter for this step, you put one probe in the water, and the other to the grounded prong of a power outlet.

Johnbob · 08/30/2006, 07:37 AM

I would also make sure all my equipment was on a ground fault circuit interrupter as well as install a titanium grounding rod. If you have questions on how to do these, you may want to consult an electrician.

stereomandan · 08/30/2006, 07:45 AM

Stick one end in the ground of your outlet, and the other in the tank. If you see an AC voltage there, you have a problem.

Be careful. Do not let your hands touch the water while your doing this in case the voltage is high.

I've been fooled sometimes when I've had a little cut on my hand, it feels like an electric shock when I put my hand in the tank.

Dan

theop · 08/30/2006, 08:33 AM

If you have built up static electricity when you touch the water, it will discharge (just like if you touch a door knob). This would be a case of you shocking the tank rather than it shocking you.

However, given the risk of stray AC voltage in your tank, I'd be very careful and fully test out what the source may be.

LOTUS50GOD · 08/30/2006, 08:43 AM

everyone should run a grounding probe anyway...

Stray voltage cannot be good for the fish.

Steven Pro · 08/30/2006, 09:40 AM

Try unplugging the heater first. They are the most likely culprits when someone gets zapped.

vdubfiend · 08/30/2006, 01:05 PM

its not all the time i get a zap... and if i touched it at any given time if it zapped me it would not zap me again for a minute or so.
i did try and isolate the problem and unplugged eVERYTHING.. individually plugging in items and thought i had it isolated to a pump.... but i couldnt get it to shock me just with the pump running- so back to the drawing board... its been a few weeks now and its not doing it anymore....

funny you mention the cut the hand cause i had reallly short fingernail- and anyway when i touched that to the water it felt like i was getting zapped....

I was under the impression that i titanium grounding probe can introduce voltage to the tank IF there is no voltage currently going through the tank?

Ill pick one of those up if i should be using one-whether or not i have a problem...

THANKS!

jeffbrig · 08/30/2006, 01:30 PM

A grounding probe can't introduce a voltage (it's grounded). It may provide a reference relative to some other voltage source already present in the tank. More importantly, it provides a path for current to flow if the tank is being energized by another voltage source. The flow of electrical current is what's dangerous to you (without a grounding probe) and your tank's inhabitants.

You seem to be using the terms voltage and current interchangeably, when they are actually two very different things. Voltage is a difference in potential between two points. Current measures the actual flow of electricity from one point to another. To visualize the difference, think of a waterfall. The height of the waterfall is analagous to the voltage. The gph of the waterfall is analagous to the current. They're related (Ohm's Law: Voltage = Current*Resistance), but very different things.

< / engineer soapbox >

vdubfiend · 08/30/2006, 06:14 PM

thanks for the clarification...
i knew at one point what to type but confused myself

Thanks again

so a probe is a good idea regardless?

chrismunn · 08/30/2006, 06:18 PM

i had that problem before. turned out to be my lights. ( the one thing that didnt have cords dangling from the water. ironic huh? ) i just stood on a plastic bucket lid when servicing my tank, untill i got rid of the tank a few weeks later. never found out a solution.

yellowtangs · 08/30/2006, 06:21 PM

unplugging one item at a time to isolate it is a safe way. What would be a good way to isolate the source without risking a shock?

yellowtangs · 08/30/2006, 06:27 PM

op! I mean unplugging one item at a time to isolate the problem is NOT a SAFE way to do.... can someone suggest a safe way to do so without risking shock... any type of test tools etc?

08/30/2006, 02:27 AM	#1
vdubfiend Registered Member Join Date: Oct 2005 Location: socal Posts: 1,195	Getting zapped occasionally- stray voltage? what is the best way to check this with a volt meter? settings? thanks!

08/30/2006, 07:36 AM	#2
jeffbrig Premium Member Join Date: Mar 2004 Location: Ft. Lauderdale, FL Posts: 5,548	If you're getting zapped when you reach in to the water, there's no need to measure. Your hand has already confirmed voltage in the water. I'd start unplugging equipment to isolate the cause. If you want to use a meter for this step, you put one probe in the water, and the other to the grounded prong of a power outlet. __________________ Beware the power of stupid people in large groups..... Current Tank Info: formerly 250g room divider

08/30/2006, 07:37 AM	#3
Johnbob Reefer Join Date: Jun 2001 Location: Oklahoma Posts: 49	I would also make sure all my equipment was on a ground fault circuit interrupter as well as install a titanium grounding rod. If you have questions on how to do these, you may want to consult an electrician. __________________ "Chance favors only the prepared mind." Louis Pasteur Current Tank Info: Display tank is 55 gal reef with 330W VHO, 120 lbs LR, ~40 species of soft and LPS corals, and with a breeding pair of tomato clowns, TurboFlotor 1000 skimmer with a Caulerpa refugium.

08/30/2006, 07:45 AM	#4
stereomandan Premium Member Join Date: Feb 2002 Location: Michigan Posts: 2,888	Stick one end in the ground of your outlet, and the other in the tank. If you see an AC voltage there, you have a problem. Be careful. Do not let your hands touch the water while your doing this in case the voltage is high. I've been fooled sometimes when I've had a little cut on my hand, it feels like an electric shock when I put my hand in the tank. Dan __________________ 90g Tank, 75 lbs Live Rock, T5, T8 and VHO Lighting, Closed loop on Snapper Pump 1.5" Sand in main tank, DSB in 38g Sump, B-ionic Daily, Temp 79, SG 1.026 LPS, Softies Current Tank Info: 90 Gallon Reef

08/30/2006, 08:43 AM	#6
LOTUS50GOD Registered Member Join Date: Mar 2003 Location: Phoenix, AZ Posts: 3,210	everyone should run a grounding probe anyway... Stray voltage cannot be good for the fish. __________________ Vertex Alpha 300 Skimmer, AI SOL Blue, Neptune Apex Controlled 360 gallon Reef Current Tank Info: born 6/26/2008- 340 reef + 100 fuge, 300lbs of figi LR

08/30/2006, 08:33 AM	#5
theop Registered Member Join Date: Mar 2005 Location: Durham, NC Posts: 1,493	If you have built up static electricity when you touch the water, it will discharge (just like if you touch a door knob). This would be a case of you shocking the tank rather than it shocking you. However, given the risk of stray AC voltage in your tank, I'd be very careful and fully test out what the source may be.

08/30/2006, 09:40 AM	#7
Steven Pro Registered Member Join Date: Nov 2001 Location: Pittsburgh, PA Posts: 9,376	Try unplugging the heater first. They are the most likely culprits when someone gets zapped. __________________ Steven Pro, yep that is my real name. Current Tank Info: Twelve 600 gallon tubs located in a greenhouse

08/30/2006, 01:05 PM	#8
vdubfiend Registered Member Join Date: Oct 2005 Location: socal Posts: 1,195	. its not all the time i get a zap... and if i touched it at any given time if it zapped me it would not zap me again for a minute or so. i did try and isolate the problem and unplugged eVERYTHING.. individually plugging in items and thought i had it isolated to a pump.... but i couldnt get it to shock me just with the pump running- so back to the drawing board... its been a few weeks now and its not doing it anymore.... funny you mention the cut the hand cause i had reallly short fingernail- and anyway when i touched that to the water it felt like i was getting zapped.... I was under the impression that i titanium grounding probe can introduce voltage to the tank IF there is no voltage currently going through the tank? Ill pick one of those up if i should be using one-whether or not i have a problem... THANKS!

08/30/2006, 01:30 PM	#9
jeffbrig Premium Member Join Date: Mar 2004 Location: Ft. Lauderdale, FL Posts: 5,548	A grounding probe can't introduce a voltage (it's grounded). It may provide a reference relative to some other voltage source already present in the tank. More importantly, it provides a path for current to flow if the tank is being energized by another voltage source. The flow of electrical current is what's dangerous to you (without a grounding probe) and your tank's inhabitants. You seem to be using the terms voltage and current interchangeably, when they are actually two very different things. Voltage is a difference in potential between two points. Current measures the actual flow of electricity from one point to another. To visualize the difference, think of a waterfall. The height of the waterfall is analagous to the voltage. The gph of the waterfall is analagous to the current. They're related (Ohm's Law: Voltage = Current*Resistance), but very different things. < / engineer soapbox > __________________ Beware the power of stupid people in large groups..... Current Tank Info: formerly 250g room divider

08/30/2006, 06:14 PM	#10
vdubfiend Registered Member Join Date: Oct 2005 Location: socal Posts: 1,195	... thanks for the clarification... i knew at one point what to type but confused myself Thanks again so a probe is a good idea regardless?

08/30/2006, 06:18 PM	#11
chrismunn Registered Member Join Date: Aug 2004 Location: Austin, Texas Posts: 4,200	i had that problem before. turned out to be my lights. ( the one thing that didnt have cords dangling from the water. ironic huh? ) i just stood on a plastic bucket lid when servicing my tank, untill i got rid of the tank a few weeks later. never found out a solution. __________________ Marine Aquarists Association of South Texas Austin Reef Club PBITAWA... Current Tank Info: 14g bio cube

08/30/2006, 06:21 PM	#12
yellowtangs Registered Member Join Date: Apr 2004 Location: Fairfax, Va Posts: 37	unplugging one item at a time to isolate it is a safe way. What would be a good way to isolate the source without risking a shock? __________________ nano reefer Current Tank Info: 50 gal bowl font

08/30/2006, 06:27 PM	#13
yellowtangs Registered Member Join Date: Apr 2004 Location: Fairfax, Va Posts: 37	op! I mean unplugging one item at a time to isolate the problem is NOT a SAFE way to do.... can someone suggest a safe way to do so without risking shock... any type of test tools etc? __________________ nano reefer Current Tank Info: 50 gal bowl font