Serious Shock in tank...how to diagnose

[joe-ejs]

Hello. I stuck my hand in my tank and got a serious shock. I was barefoot when it happened. When I put my rubber flip flops back on, no shock. I am in an older home with no ground in most of the outlets. Tank has been up for a year. This is the first time it has happened. Fish are all fine.

How Can I measure the voltage in the tank? I have a voltmeter. I assume positive in water and ground to some "grounded" spot in the house?

And how do I fix this? We have had significant rain in the last week to the point where 50% of the yard is under water, if that matters.

Any help is very much appreciated.

 

[Catskiller]

Linking in the experts
@Sleepydoc

 

[thatmanMIKEson]

in order to get around no gtound it is common to change 2 wire receptacles with gfci receptacle (ground fault circuit interrupter).

 

[thatmanMIKEson]

do it like an old electrician stick your head in the water untill you get shocked, then unplug things untill the shock goes away ....simple

 

[joe-ejs]

So update...I measure 36V in the tank with a known good ground...obviously there is some level of current associated with that....by unplugging each plugged device one at a time, will that drop to zero, telling me where my problem is coming from, or is the 36V a result of the tank currently not grounded..and is it a different that what is causing the shock? Obviously once I get the tank grounded, it should read near zero.

In other words, just to confirm, by unplugging each device one at a time, is the way to find the bad part is to continue to measure the voltage in the tank until it drops to 0?

Just trying to verify the situation I am dealing with. Obviously I have 2 problems as I see it...(1) a faulty device (pump,heater,etc) that is causing the shock and (2) ungrounded tank which caused the current to choose me rather than least resistance path to ground (grounding probe, etc)..

Thanks

 

[thatmanMIKEson]

Yes unplug one at a time if it suddenly goes away id say thats your issue..... but im wondering about your test method to get 36v where are you placing your leads and if you are getting 36 volts the meter reads flow so im not sure how you could test flow of electricity, thats why I ask where you place your leads of the meter, and is this on a/c voltage setting?

 

[joe-ejs]

Yes unplug one at a time if it suddenly goes away id say thats your issue..... but im wondering about your test method to get 36v where are you placing your leads and if you are getting 36 volts the meter reads flow so im not sure how you could test flow of electricity, thats why I ask where you place your leads of the meter, and is this on a/c voltage setting?

Hello..I am placing the positive probe in the water and the negative probe is going to a known good ground in a different wall outlet by the refrigerator that is grounded.

 

[vetteguy53081]

Start with return pump, then skimmer, then powerheads and then heater
Typical culprits

 

[CanuckReefer]

So update...I measure 36V in the tank with a known good ground...obviously there is some level of current associated with that....by unplugging each plugged device one at a time, will that drop to zero, telling me where my problem is coming from, or is the 36V a result of the tank currently not grounded..and is it a different that what is causing the shock? Obviously once I get the tank grounded, it should read near zero.

In other words, just to confirm, by unplugging each device one at a time, is the way to find the bad part is to continue to measure the voltage in the tank until it drops to 0?

Just trying to verify the situation I am dealing with. Obviously I have 2 problems as I see it...(1) a faulty device (pump,heater,etc) that is causing the shock and (2) ungrounded tank which caused the current to choose me rather than least resistance path to ground (grounding probe, etc)..

Thanks

Electrician here...
Yep you are on the right track, by unplugging each piece of equipment until the culprit is found. As for your receptacles very important to install a GFCI receptacle on this circuit, especially in a system with iffy to no ground. In some knob and tube wiring around here this is what we'll do if wiring is not changed out completely. It will measure the imbalance and likely trip immediately. Also would recommend a ground probe in conjunction, but seeing as you dont seem to have a grounded outlet near tank, this may not be possible. Most effective / safest suggestion is a new circuit grounded direct back to panel, GFCI with ground probe.

 

[joe-ejs]

Electrician here...
Yep you are on the right track, by unplugging each piece of equipment until the culprit is found. As for your receptacles very important to install a GFCI receptacle on this circuit, especially in a system with iffy to no ground. In some knob and tube wiring around here this is what we'll do if wiring is not changed out completely. It will measure the imbalance and likely trip immediately. Also would recommend a ground probe in conjunction, but seeing as you dont seem to have a grounded outlet near tank, this may not be possible. Most effective / safest suggestion is a new circuit grounded direct back to panel, GFCI with ground probe.

Hi CanuckReeefer...

So I pulled the outlet off the wall in another location of the house where I was showing a ground circuit and this is what I found...looks like they jumped ground to the common side. What is the effect here?. I would assume no path to ground correct? This seems scary. Is this better than no ground?

 

[CanuckReefer]

Hi CanuckReeefer...

So I pulled the outlet off the wall in another location of the house where I was showing a ground circuit and this is what I found...looks like they jumped ground to the common side. What is the effect here?. I would assume no path to ground correct? This seems scary. Is this better than no ground?

Hello! Oh my.... yes this is a NO NO. The Neutral wire is already grounded so we are potentially creating a ground loop or other sordid mess here. My suggestion is pick up a GFCI outlet time being. Connect the Hot and neutrals as you would normally and leave ground screw with nothing. At least it will trip on imbalance. This definitely looks like knob and tube to me based on the connection points deeper in the box.
Did you find the equipment that was giving you the stray voltage?

 

[joe-ejs]

Hello! Oh my.... yes this is a NO NO. The Neutral wire is already grounded so we are potentially creating a ground loop or other sordid mess here. My suggestion is pick up a GFCI outlet time being. Connect the Hot and neutrals as you would normally and leave ground screw with nothing. At least it will trip on imbalance. This definitely looks like knob and tube to me based on the connection points deeper in the box.
Did you find the equipment that was giving you the stray voltage?

So I found it to be the titanium heater…unplugged it from the ink bird and voltage dropped to 3v.
Now my next question is whether 3v is dangerous …obviously the tank is still not grounded …should I be getting absolute 0V ?

 

[thatmanMIKEson]

Keep unplugging.....you tell us, i don't have any volts in the way you described to test just m.v but it will pick that up in the air..

 

[WallyB]

#1. A fish tank or any place where there is water should be run on a GFCI outlet, however that may not be enough to prevent a zap (if you have ungrounded eqipment like a 2 prong heater, which has no ground).
The only way is GFCI and a Ground probe, and proper wiring.

I've been zapped a few times. Many reasons.

This might help explain things.

I made this video after my last shock


I'm not giving advice how to fix your issue, just giving information.

Improper electrical setup on any water exposed environment could be life or death situation. Or just a strong ZAP that won't kill you, but will freak you out.

Whatever you do, you must find out the source of AC power entering your tank water. BTW. are you measuring DC or AC voltage with your MultiMeter. You need to measure AC between your tank-water and a Proper Ground.

 

[WVNed]

Or just wear your flip flops. There is always some induced voltage in a tank without a ground probe.

 

[Taipan88]

So I found it to be the titanium heater…unplugged it from the ink bird and voltage dropped to 3v.
Now my next question is whether 3v is dangerous …obviously the tank is still not grounded …should I be getting absolute 0V ?

I was reading the replies to see if this was mentioned. In my experience it has always been a heater that gives a shock to the water. All other appliances tend to trip the safety switch in my house.
Also in saying that, I have found that I get around 2 years before a heater goes.. either by itself or I accidently wack the thing and it shatters.

 

[Cygnus]

So update...I measure 36V in the tank with a known good ground...obviously there is some level of current associated with that....

What is your meter set to measure? If it is scalable you need to set it to mv first then volts depending on how much voltage there is to read. Remember its not volts alone that kill, its the combination of volts and current that kills.

Yes unplug one at a time if it suddenly goes away id say thats your issue..... but im wondering about your test method to get 36v where are you placing your leads and if you are getting 36 volts the meter reads flow so im not sure how you could test flow of electricity, thats why I ask where you place your leads of the meter, and is this on a/c voltage setting?

AC current cycles. It only flows when there is a load connected. The meter reads the presence of volts.

Hello..I am placing the positive probe in the water and the negative probe is going to a known good ground in a different wall outlet by the refrigerator that is grounded.

First there is no positive or negative in an AC system. You may just call it the red and the black leads. Either way AC voltage can be read.
However, the ground you sourced is not connected in any way to your receptacle. So I would not trust any readings like this.

Electrician here...
Yep you are on the right track, by unplugging each piece of equipment until the culprit is found. As for your receptacles very important to install a GFCI receptacle on this circuit, especially in a system with iffy to no ground. In some knob and tube wiring around here this is what we'll do if wiring is not changed out completely. It will measure the imbalance and likely trip immediately. Also would recommend a ground probe in conjunction, but seeing as you dont seem to have a grounded outlet near tank, this may not be possible. Most effective / safest suggestion is a new circuit grounded direct back to panel, GFCI with ground probe.

GFCI wins each time. And like you say he has no grounding conductor to plug his probe into.
GFCI can be used in lieu of a three wire receptacle. No ground required for a GFCI to work.

Hi CanuckReeefer...

So I pulled the outlet off the wall in another location of the house where I was showing a ground circuit and this is what I found...looks like they jumped ground to the common side. What is the effect here?. I would assume no path to ground correct? This seems scary. Is this better than no ground?

I have seen this a lot. Disconnect the green wire and remove it.

So I found it to be the titanium heater…unplugged it from the ink bird and voltage dropped to 3v.
Now my next question is whether 3v is dangerous …obviously the tank is still not grounded …should I be getting absolute 0V ?

No telling. 3 volts can kill. Its the combination of volts and current that kills. Use a GFCI. Then you will be safe.

 

[thatmanMIKEson]

Hello! Oh my.... yes this is a NO NO. The Neutral wire is already grounded so we are potentially creating a ground loop or other sordid mess here. My suggestion is pick up a GFCI outlet time being. Connect the Hot and neutrals as you would normally and leave ground screw with nothing. At least it will trip on imbalance. This definitely looks like knob and tube to me based on the connection points deeper in the box.
Did you find the equipment that was giving you the stray voltage?

You stumbled across the correct answer A . The only legal thing to do (that is illegal) is put in a two wire receptacle, or a gfci receptacle or braker in..thats a very BAD way to fool the home inspector and his "plug checker" prior to a home sale. Usually. Or it was someone that wanted a plug checker to say grounded to feel better either way, not standard practice but do not worry nothing will happen they both go back to the panel (ground and neutral) and land on the same bar, unless its a sub panel feed now were talking oranges and tangerines in early spring!

You like this electrical stuff ..the ground wire came later (in the years as homes were built better) as added safety in case the neutral wire was compromised along the way there would still be a short to a grounding conductor to blow the fuse or trip the braker ...one current carrying conductor, one grounded conductor and one grounding conductor is used today.

 

[thatmanMIKEson]

AC current cycles. It only flows when there is a load connected. The meter reads the presence of volts.

I'm not sure what your saying here but it sounds like your on the right track and under control

 

[Nikki Polley]

So update...I measure 36V in the tank with a known good ground...obviously there is some level of current associated with that....by unplugging each plugged device one at a time, will that drop to zero, telling me where my problem is coming from, or is the 36V a result of the tank currently not grounded..and is it a different that what is causing the shock? Obviously once I get the tank grounded, it should read near zero.

In other words, just to confirm, by unplugging each device one at a time, is the way to find the bad part is to continue to measure the voltage in the tank until it drops to 0?

Just trying to verify the situation I am dealing with. Obviously I have 2 problems as I see it...(1) a faulty device (pump,heater,etc) that is causing the shock and (2) ungrounded tank which caused the current to choose me rather than least resistance path to ground (grounding probe, etc)..

Thanks

Hi, I had the same once upon a time, it was the heater, put new one in and all was good