When to deal with stray voltage.

[jhoop]

FWIW......
Checked my tank with a Beckman 310 Digital meter. 28.2 volts from ground to water.

Then checked with a Simpson 260 analog meter 6.0 volts. My thought is, it is EMF noise. Not true 60 cycle voltage. My system is plugged in to a GFCI that is grounded and polarity is correct. I might try tonight with a Tektronics Oscilloscope tonight. See what kinda of "wave " is there.

 

[saltyfilmfolks]

Hi! Yes, there are a few different types of fault ciruit interrupters, but the ones sold at your local hardware store for consumer home use, look at the difference in the current flowing through the hot lead, and the current flowing through the neutral lead. If this current exceeds 5 milliamps, it will trip. Induction, whether it be an electric field from standing voltage, or an electromagnetic field from flowing current, *should* have little effect on the residential gfci...the "emf" is dissipated constantly regardless whether it is through the air, or the saline solution in our tanks, etc, and doesn't affect real current measurements (but will have an effect on vars or volt-amps-reactive). I could be wrong, but I am pretty sure the gfci generally "see" an emf flow as they (afaik) don't "see" powerfactor (vars).
Industrial fault detectors are an entirely different beast, and yes, most now a days are fully programmable, including high-sensitivity "maintenance mode", with settable inverse time/current delays in normal mode. While a residential gfci does have an inverse current/time function, they are not adjustable.

Slightly off topic...part of the fault detection and tripping systems we use for monitoring the powerlines in the grid use similar equipment to what you described at your work....but with a ton more relaying/communications between injection and tripping switchgear (it's very important on the grid for all the breakers and switches to talk to each other and decide who is going to do the tripping, and when, and who is going to sit around and wait incase somebody else fails to do thier job lol).

As I have said before, a ground probe in the tank, without a gfci supplying the tank, imho could be a deadly trap.

Cheers!

yup!

 

[Dom]

After an extended amount of research today, I've concluded that there isn't a right answer to this issue. While everyone is in agreement that any voltage in the tank isn't a good idea, considering the problem "fixed" is a matter of perspective. Today, I had an extensive conversation with a licensed electrician whose work includes installing electric for in ground pools. From the conversation with him I have concluded:

Without the titanium grounding rod, the tank has 42v. Voltage is pressure and without it, there can't be current. So, no voltage = no current. Think of my tank without the grounding probe as a 42v battery and with the grounding probe, as a 42v DEAD battery. Additionally, my life is more important to me than anything in the tank; inhabitants can always be replaced, so, I'd rather risk having a "tank full of sushi" than my own life.

I don't believe a GFI outlet will serve any real purpose with my configuration. As I've mentioned previously, I have an APC-1500 battery backup which stands between line power and all the devices in the tank. A GFI outlet would only serve to protect the line side of the battery backup. The device side is protected by an integrated circuit breaker. I have replaced the 20 amp breaker on the ircuit which supports the tank with a 20 amp arc fault breaker.

In the end, it all comes down to what you are willing to risk. I'd rather risk my fish than have one of my nieces stick their hand in my tank and give themselves a potentially fatal zap.

 

[ThePapa]

After an extended amount of research today, I've concluded that there isn't a right answer to this issue. While everyone is in agreement that any voltage in the tank isn't a good idea, considering the problem "fixed" is a matter of perspective. Today, I had an extensive conversation with a licensed electrician whose work includes installing electric for in ground pools. From the conversation with him I have concluded:

Without the titanium grounding rod, the tank has 42v. Voltage is pressure and without it, there can't be current. So, no voltage = no current. Think of my tank without the grounding probe as a 42v battery and with the grounding probe, as a 42v DEAD battery. Additionally, my life is more important to me than anything in the tank; inhabitants can always be replaced, so, I'd rather risk having a "tank full of sushi" than my own life.

I don't believe a GFI outlet will serve any real purpose with my configuration. As I've mentioned previously, I have an APC-1500 battery backup which stands between line power and all the devices in the tank. A GFI outlet would only serve to protect the line side of the battery backup. The device side is protected by an integrated circuit breaker. I have replaced the 20 amp breaker on the ircuit which supports the tank with a 20 amp arc fault breaker.

In the end, it all comes down to what you are willing to risk. I'd rather risk my fish than have one of my nieces stick their hand in my tank and give themselves a potentially fatal zap.

I had some questions about APC's and GFI's so I called APC and talked with Andrew, he is an EEE in the Tec support department. IN short APC's may not work well plugged into a GFI but more to the point an APC is not a GFI and as this is a wet location scenario a GFI is all but mandated, that is why you are required by code in most locations to have them in the bath, kitchen and outdoors. His recommendation in that scenario, reef tanks, is to have the GFI after the UPS even several plug in style on an outlet strip so as to not have a single point of failure. Yes the ground rod is important to get that potential to zero, especially with all the two wire equipment in most tanks, but without the GFI huge dangers lurk in your tank IMO. Let us not forget that with an APC or other battery backup we have now introduced another 120 V electrical feed so even if you unplug it from the wall you must be aware that it is hot, fed from the battery. Yes I have seen people make that discovery the hard way. I come from a shipboard electrical environment, steel hull as ground, stuff fails all the time even with 24/7 monitoring so can't be too careful.

 

[Dom]

I had some questions about APC's and GFI's so I called APC and talked with Andrew, he is an EEE in the Tec support department. IN short APC's may not work well plugged into a GFI but more to the point an APC is not a GFI and as this is a wet location scenario a GFI is all but mandated, that is why you are required by code in most locations to have them in the bath, kitchen and outdoors. His recommendation in that scenario, reef tanks, is to have the GFI after the UPS even several plug in style on an outlet strip so as to not have a single point of failure. Yes the ground rod is important to get that potential to zero, especially with all the two wire equipment in most tanks, but without the GFI huge dangers lurk in your tank IMO. Let us not forget that with an APC or other battery backup we have now introduced another 120 V electrical feed so even if you unplug it from the wall you must be aware that it is hot, fed from the battery. Yes I have seen people make that discovery the hard way. I come from a shipboard electrical environment, steel hull as ground, stuff fails all the time even with 24/7 monitoring so can't be too careful.

Funny you should mention GFI AFTER the APC. As I mentioned in an earlier post, I put an ARC FAULT breaker in the panel. When I was done, I thought I should just install and ARC FAULT power strip after the APC.. I'll definitely be doing that too.

 

[Dom]

Recommendations for a GOOD Arc Fault power strip?

 

[ThePapa]

Funny you should mention GFI AFTER the APC. As I mentioned in an earlier post, I put an ARC FAULT breaker in the panel. When I was done, I thought I should just install and ARC FAULT power strip after the APC.. I'll definitely be doing that too.

Thought, the transformer in the APC may introduce transformer isolation of your tank loads negating any ark or GFI protection at the power panel or power supply side. In any case if there is a power outage a power panel ark fault or GFI will again not protect you. Only load side, of the APC, ark fault or GFI protection will work and then only if a wet ground rod or other wet grounding is in place.

 

[Dom]

So why would a AFI outlet plugged into the battery backup and then a power strip in to the AFI outlet not offer protection from an arc?

 

[ThePapa]

It does, that is my point and the only way to get protection.

 

[1stNoel]

Hello, everyone.

So I was setting up a second sump on my tank and, while adjusting the overflow box, started feeling that sharp "tingle" of a shock. Didn't think much of it initially, as I was working on other areas of the tank without a problem (it's 8 feet long). Later on that day, I started retrieving my PVC tubes from the tank to replenish the nori that I attach to them (cheap food clip) and I got a good jolt. The only thing in that area that had electricity was a powerhead, so I removed it from the tank...thinking I eliminated the problem. Later on I was in the sump changing out the filter socks (this is located below that same area) and I got another shock.

The next day I purchased a digital multimeter, and checked the 2 sumps and various areas of the tank (using AC 200...the multimeter only has 200 & 600 as options).

Here are my readings:

• Sump 1 contains 2 heaters, a powerhead, and the return pump. It ranged from 0.0 to 0.2.
• Sump 2 contains a skimmer, reactor, and return pump. It read about 0.2. This is the sump where I got the jolt.
• The display tank contains 2 Gyres and Kessil AP700s mounted 7" above the waterline. It ranged from 0.2 to 0.7...even in the spot where I was getting shocked.

I tested again about an hour later. Initially it was reading the same, and then it spiked to 48.6. I moved around the immediate vicinity and it dropped to 11.8. I pulled it out to test other spots in the tank and it dropped back down to 0.7.

I tested a few more times since then, but I can't replicate that spike. It keeps reading 0.7.

What are my troubleshooting options if I'm only getting an occasional spike?

A few other facts, in case they make a difference: I did have a bad hangnail that exposed some skin (I keep hearing about papercuts intensifying the shock...not sure how that works so please enlighten me), I'm typically barefoot when working on the tank, and typically on a wooden stepstool if I'm sticking my hands in the tank.

 

[saltyfilmfolks]

how are you testing. Water to a confirmed grounded outlet? in the ground hole of course.
what is your floor made of. wood cement?
Have you checked for correct polarity at the outlet?
what tank was the 46v spike taken from.
and are you using multiple circuits from the house and are they dedicated to the tank or are shared with an appliance.

 

[1stNoel]

how are you testing. Water to a confirmed grounded outlet? in the ground hole of course.
what is your floor made of. wood cement?
Have you checked for correct polarity at the outlet?
what tank was the 46v spike taken from.
and are you using multiple circuits from the house and are they dedicated to the tank or are shared with an appliance.

Thanks for the quick reply.

Here are the answers (in order):

• I'm testing from the water into my UPS battery back-up that was connected to my power strips. I recently disconnected it because it couldn't support all the wattage running to my tank (it maxes out at 1500W).
• My floor is wood laminate.
• I don't know much about polarity. I'll need to research how to test for it.
• The spike was taken from the 300g display tank (not the sumps).
• There are two 15 Amp breakers controlling my room. I think my TV, Xbox, ceiling lights, and ceiling fan are on the same breaker as the aquarium (plugged in about 8 ft away on another outlet). My other breaker controls my CPU and my 55g quarantine tank.

 

[melev]

You need a $11 multimeter, available at Harbor Freight. I show specifically how to measure for stray electricity in this article: http://www.reefaddicts.com/content.php/45-How-to-Test-for-Stray-Electricity

 

[Russ265]

You need a $11 multimeter, available at Harbor Freight. I show specifically how to measure for stray electricity in this article: http://www.reefaddicts.com/content.php/45-How-to-Test-for-Stray-Electricity

methinks you didnt read.

 

[Russ265]

Hello, everyone.

So I was setting up a second sump on my tank and, while adjusting the overflow box, started feeling that sharp "tingle" of a shock. Didn't think much of it initially, as I was working on other areas of the tank without a problem (it's 8 feet long). Later on that day, I started retrieving my PVC tubes from the tank to replenish the nori that I attach to them (cheap food clip) and I got a good jolt. The only thing in that area that had electricity was a powerhead, so I removed it from the tank...thinking I eliminated the problem. Later on I was in the sump changing out the filter socks (this is located below that same area) and I got another shock.

The next day I purchased a digital multimeter, and checked the 2 sumps and various areas of the tank (using AC 200...the multimeter only has 200 & 600 as options).

Here are my readings:

• Sump 1 contains 2 heaters, a powerhead, and the return pump. It ranged from 0.0 to 0.2.
• Sump 2 contains a skimmer, reactor, and return pump. It read about 0.2. This is the sump where I got the jolt.
• The display tank contains 2 Gyres and Kessil AP700s mounted 7" above the waterline. It ranged from 0.2 to 0.7...even in the spot where I was getting shocked.

I tested again about an hour later. Initially it was reading the same, and then it spiked to 48.6. I moved around the immediate vicinity and it dropped to 11.8. I pulled it out to test other spots in the tank and it dropped back down to 0.7.

I tested a few more times since then, but I can't replicate that spike. It keeps reading 0.7.

What are my troubleshooting options if I'm only getting an occasional spike?

A few other facts, in case they make a difference: I did have a bad hangnail that exposed some skin (I keep hearing about papercuts intensifying the shock...not sure how that works so please enlighten me), I'm typically barefoot when working on the tank, and typically on a wooden stepstool if I'm sticking my hands in the tank.

set 1 heater to max settings. use voltmeter.
set other heater to max settings. use voltmeter.

heaters should always be scrutinized.

 

[Mattrg02]

Dont know if it's been suggested, but we probably should be measuring current draw, not voltage. Magnetic fields nearby will always create a voltage reading. It's the current that we should worry about.

If there isn't a return path to ground, then there isn't going to be any current flow. Current flow is electrons being pushed through a conductor from a high potential (source) to a low potential (ground).

Btw-A ground probe won't draw ALL the current to ground. Just most of it. Current will take ALL paths to ground at the same time.

Prevent a path to ground and your tank should be fine. (No metal stands)

I used to get quite a tingle when I was barefoot. Also had 5 power heads in there along with a heater. Nothing ever was hurt by it since the tank is up on a wood stand.

Also, since we use a lot of AC stuff, there will be small current to ground due to capacitance between your tank and the earth.

So, measure current draw. Shouldn't be a lot.

Edit-That's what I get for reading threads on iPhones. Sorry for the repeated idea.

 

[bobman]

I think you need to test it differently, at the outlet itself as one person mentioned. Getting a reading using the stand as one leg of the measurement is disconcerting. Here's my article: http://www.reefaddicts.com/content.php/45-How-to-Test-for-Stray-Electricity

Nice write up but no GFCI on that outlet you are using?

 

[melev]

Nice write up but no GFCI on that outlet you are using?

Some outlets are GFCI, some are not. Some breakers to my fishroom are GFCI, some are not. For example, heaters and lighting are on GFCI. Return pumps are not. Things that will kill me are on them, but I don't want main circulation off because of a nuisance trip while I'm away from the tank.

 

[redfishbluefish]

I think @Russ265 hit the nail on the head.....if you have minimal voltage and suddenly have a voltage leak...and it's intermittent, look at the heaters.

 

[bobman]

Or be cool like me I dont use heaters