Neptune Aquatics

My tank is a death trap.

So randomly (it seems) the GFI trips on my tank like once every 6 months after some agressive splashing from the fish. And a few times I've shocked myself.

This is because there is 110 VAC potential between the water and my lights ... yeah.

I thought it was my old halide fixture so I replaced them, but my new LED's are still showing this. Now I have an idea why.

I've actually shut off all the electrical system except the lights and the potential was still there. NONE of my house outlets have any ground at all (tube and knob wiring, everything is GFCI protected instead).

BUT the lights have a ground plug and the powerstrip (I've replaced it, it's not the power strip) also has a "ground".

I bought the tank/stand many years ago and the stand has an electrical "panel" Which is many outlets with three plugs... basically DIY power strips with switches to turn the outlets on and off individually. Quite convenient ... however ... I think the guy who built it didn't do a good job and the neutral or hot line of one of the outlets is shorting to the "ground" wire... so the only "grounded" piece of equipment (the lights) is actually somehow charged.

Now ... I'm not sure and maybe you guys can help me here but here's some facts;

1) I can touch the water without any trouble or shock at all, I'm standing in bare feet on my hardwood floor
2) I can touch the lights without any trouble or shock at all, I'm standing in bare feet on my hardwood floor
3) If I and cleaning the tank with my hand in the water and my elbow brushes the lights (the housing of the lights) then I get shocked and the GFCI shuts down everything.

4) Since the housing of the lights is "grounded" (tied to the ground pin of the electrical plug), it is most likely a miswiring of that "ground" somewhere. If it were miswired to the "hot" side, I think the lights would not work or they would have blown a fuse. The lights are LED with a controller, so it's not just a bulb.


The outlets on the wall were installed by some handyman, but he used Romex wiring with a ground wire, I'm not sure if he connected the ground wire to the ground at the panel, but even if he did, I don't thing that the main panel, due to age had any proper grounding. I think it's half-a**ed and there is a copper wire running to a water line. Not proper NEC.

Typically the neutral line is connected to the ground line AT the panel ONLY.

One theory I have is that the guy at some point made a mistake and cross wired the hot/neutral lines, but I think this would have blown a fuse but I'm not sure.

My current solution ... Get some power strips to replace the in-stand electrical "system" as it turns out I never use the switches anyway, and now I'm scared of it.

Also ... test the lights by plugging the light-power-strip to an actual wall outlet elsewhere and again test the potential between water and lights.

I'm wondering though, how I can get a full house AC voltage between water and light though as ... I can imagine that the water itself is only connected to anything electical via that panel and the heaters/pumps (the pumps are actually not submerged as they are MP-40s).

If the outlets were actually grounded I could at least test the water and the lights against ground to see which of the two is "hot" and which is actual ground.

V
 
My father at one day wired the electrical panel in his garage/workshop... yeah he didn't have any clue what he was doing "wires are wires!" was literally his response to this story. Well needless to say my uncle was over one day when they were gone to do some plumbing on the house, nice cool morning with dew on the grass my uncle with a saw (or something) plugged into said garage kneels down in the grass and BZZZZZZZZZZZT gets shocked. So yeah things can be badly miswired and still "work".

That said, my first solution would be to plug the light somewhere else, get an extension cord if you have to see if there still is an issue. Another possibility is you have a pump (or anything electrical) that has a cracked housing, if electricity is leaking into the tank and the light's metal chassis is grounded then as soon as you touch it there's your path to ground. I would say test the tank versus a grounded outlet, but you don't have one?

But copper ground going to a water line isn't a huge issue, however if they tied the neutral to a water line that would be a huge issue.
 
More than likely it’s your lights that are shorting out to the housing somewhere. Unplug your lights from the outlet, and see if it still happens. If it doesn’t, then replace your lights with ones that won’t kill you.
 
That's what I use to check wiring at outlets; pretty simple tool easy to understand.

There might be an issue where the neutral might be switched somewhere; perhaps at one of the light switches that might share with an outlet the power.

If Vince suspects some of the eqt leaking current, an easy way is to get a multimeter, stick one probe in the water and the other end to the ground of any outlet; then switch on every single piece of equipment and check for the display to change.

Some older power panels have only neutral and hot terminals; a ground bar can be added to them.

As with any electrical work; main power must be turned off if you are to add a grounding block

I got a good buddy who is an electrician and he happens to be sitting right here with me.
He says to go buy this and make sure that the plugs are grounded. If it's not grounded, he says don't play with it, you are definitely risking death!

https://www.amazon.com/Gardner-Bend...coding=UTF8&psc=1&refRID=Z1PQ3CHNXQYCS92SN75E
 
Almost sounds like the hot is back feeding into the ground. My outlets in the house were once wired by a previous owner with a loop from neutral to ground to fake the ground. Very dangerous.
 
More than likely it’s your lights that are shorting out to the housing somewhere. Unplug your lights from the outlet, and see if it still happens. If it doesn’t, then replace your lights with ones that won’t kill you.

I actually did that. I was running metal halides and touching the reflectors would trip the GFI. So I swapped them to electronically controlled LEDs. Same issue. Though yes, I believe the problem is the ground wire in the hacked-together stand "power strips" are shorting somewhere.

And yes, when I get back from vacation, I think I'll get my real electrician to give me a quote for replacing the T&K wiring with modern romex or at least getting them all properly grounded. Probably several thousand but that's cheaper than a serious electrical shock.


V
 
That's what I use to check wiring at outlets; pretty simple tool easy to understand.

There might be an issue where the neutral might be switched somewhere; perhaps at one of the light switches that might share with an outlet the power.

If Vince suspects some of the eqt leaking current, an easy way is to get a multimeter, stick one probe in the water and the other end to the ground of any outlet; then switch on every single piece of equipment and check for the display to change.

Some older power panels have only neutral and hot terminals; a ground bar can be added to them.

As with any electrical work; main power must be turned off if you are to add a grounding block


What I did was take a multimeter, with one probe in the water and the other touching the light housing ... 110V (ish), I then turned off all the pumps (the power-strip thing has switches) and unplugged the heaters ... same issue ... which is what puzzles me.

I switched the power strip that the lights were conencted to to another one. Same issue. I will unplug the lights and run an extension cord to another outlet to see if this still happens.

More and more, I suspect bad wiring in the "DIY panel" in the tanks stand.

And to be clear, when I bought the stand (I'll take pics later) it came with a bank of electrical outlets, three rows of 4 outlets, with a plug for each row. Each row had three outlets (outlet = 2 plugs, these are house outlets) on their own switch and one outlet on a timer. So, cool right? I mean I can control all of the equipment from this, including three timed outlets. BUT I never questioned the quality of work that the guy did. So to remove this, I've bought some power strips with 9 foot cords to replace this mess of outlets, since it was convenient to have the switches, but not necessary. I'll let you know how it goes.

V
 
And yes, when I get back from vacation, I think I'll get my real electrician to give me a quote for replacing the T&K wiring with modern romex or at least getting them all properly grounded. Probably several thousand but that's cheaper than a serious electrical shock.
While I'm not a fan of knob and tube wiring, it isn't necessarily "bad" however the bad happens when someone sees the wiring "oh hey I'll just splice right into it" which is how you would make branches with K&T which was quite convenient, however if you had someone throw it together like my father then they probably splices a hot wire to the neutral in your junction box. That little tool Evan posted will let you know when you plug it in, at the very least you'll be able to isolate the wiring to a particular circuit and then get an electrician to maybe fix that one.
 
Given your listing of facts, it seems you might have an open ground PLUS a mild leak from hot to ground in the lights.
Although without measuring everything, really hard to know.

That tool will help on the plugs.

But: It really seems like you might also have a problem in the lights.
So just in case:
Plug in the lights to a know-good GFCI plug, perhaps in your kitchen, using an extension cord.
 
I tried out the plug tool which indicates proper wiring and ground is ground. The outlet on the other side of the room shows open ground, which I knew. I’ll go right down to unplugging everything and start with a blank slate.

The bad light theory is still possible, but I replaced three lights with three other separate light fixtures. I don’t believe six fixtures are all bad.... but I won’t rule it out. I’m wondering also about salty water and creep shorting things too.

V
 
I was having issues where I was seeing voltage (80v) on a neutral. I looked all over the place and finally found that a neutral wire came loose from the wire nut that it was in. It just popped loose after years of being fine. It took me hours to finally track it down though.
 
OK I found the culprit ... mostly.

I discovered a heater plugged directly into the wall outlet and not the outlet array in the stand. I unplugged everything from the wall. That heater, when plugged in was leaking 110V !!

OK, so here's the rest of it, and maybe it's explainable. But...

(Voltage reading between ground plug in the outlet array and sump water)

Two things plugged in ... the outlet array and the bad heater, reading around 110-ish
Unplug bad heater, voltage drops to zero (I think)
Plug into the wall a power strip that is connected to a pump in my kalk mixer and my top off pump.... voltage goes to 8V
Plug in MP-40 pump to wall outlet, voltage increases

Start plugging things back into the outlet array...
maxijets, increase voltage 2-3 volts
heater increases voltate 3-5 volts
plug in THE LIGHTS ... voltage DOES NOT CHANGE (makes sense, lights aren't touching the water)

So basically everything that I plug in increases the water-to-ground voltage !
I'm guessing it is all inductive, since most of those things are spinning magnets (I mean, look a the MP-40 pumps!)
I am trying not to "ground" the tank water by touching the lights (at ground potential) and the water (now up to 36 - 40 V)

I'm wondering it it will still shock me and trip the GFI, I'm not willing to test it BUT it sure as hell is better than probably a bare wire in a broken heater and ground!

Now I've read that the 40V is "low voltage" and "nothing to be too worried about" since it's all induced voltage. I'm rusty on power systems so I don't know.
I do know that I shouldn't really expect 0V from tank water (200 ish gallons of salt water) to ground since ... why should the water be at ground potential if it's not electrically connected to ground (??)

BUT the main shocker is solved ... what do you guys think about this extra probably induced voltage?
I wonder if I can charge my iPhone by placing it near my fish tank ...

V
 
First, just to double check, are you measuring DC or AC voltage?

Second, I would suggest an experiment:
Turn everything on.
Connect an extension cord to that plug. Take the other end outside, and measure voltage between the ground on the extension
cord and a spot of wet dirt, metal gas pipe, or something like that.
To really see how good that plug-ground is.

FYI: That is not really the way induction works.
The alternating magnetic field in a pump will induce some current in the water, but the current would
flow back on itself, really just heating the water very slightly. It would not build up potential to ground.
So it is simple leakage.
The resistance of the plastic insulation on the wire is definitely not infinite, so you always have
some leakage.

They sell nice titanium or stainless grounding wires. You might simply want to get one.
 
The mp40 should have zero electric leakage into your tank. I’m pretty sure it would be impossible

Agreed.
But it is also impossible for it to induce a voltage between water and earth ground through induction.
In theory it could do it slightly through capacitance. But with the thick glass and really no surface area, that is basically zero also.

That is why I suspect the ground itself.
He is measuring voltage between tank and the ground plug.
The assumption is that it is the tank with the extra voltage, but it could actually be the ground plug with the voltage.
 
I have a finex titanium heater that is said to be a grounding probe for the tank. When I checked it there was only 0.002 volts that showed up in the tank.
 
Back
Top