When to deal with stray voltage.

1stNoel · Jun 22, 2016

redfishbluefish said:
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.

I checked the entire tank again today, and maxed out at about 0.9 in the tank...0.2 and 0.0 in the sumps.

I'll test the heaters tomorrow. It makes sense, as the 2nd heater is a back-up that is set at a slightly higher temp...so maybe it's those times it's kicking on that zaps me.

1stNoel · Jun 22, 2016

melev said:
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

Thanks for the article.

I like the idea about using the extension cord to more easily maneuver around with the multimeter.

I also think you may have hit on something with the flooring. I have had a few leaks (one major one when I spilled about 20 gallons doing a water change), and that area of the tank is where the water accumulated. That was about 2 months ago. Not sure if the padding underneath is still moist and causing the issue. Especially a 48V spike.

I like to tinker with my tank, so I hate feeling like I can't stick my hands in there. :mad:

Mattrg02 · Jun 22, 2016

1stNoel said:
Thanks for the article.

I like the idea about using the extension cord to more easily maneuver around with the multimeter.

I also think you may have hit on something with the flooring. I have had a few leaks (one major one when I spilled about 20 gallons doing a water change), and that area of the tank is where the water accumulated. That was about 2 months ago. Not sure if the padding underneath is still moist and causing the issue. Especially a 48V spike.

I like to tinker with my tank, so I hate feeling like I can't stick my hands in there. :mad:

Insulate yourself from ground and you'll be ok. That is unless you have one faulty device providing a path to ground for another device and you get caught in the path.

ThePapa · Jun 22, 2016

I'm not a big fan of using my hand as a meter to test for electricity and certainly not as a safety device to see or find out if something is broken. Safe practices will allow you to enjoy your reef experience for many years so don't become a statistic. So IMO ground your tank system with a titanium ground rod and bond it to anything metal like a tank stand and your electrical devices, long story short it is an important part of your safety triangle. Next will be ground fault or arc fault protection after your UPS if you are using one, IMO everything in or around the wet environment should be protected per electrical code in most areas . Do not connect GFI's in series with each other if you are using more than one, parallel is OK. So if after your UPS you don't want everything to have a single point of failure, plugin multiple GFI's into your outlet strip and distribute your loads among them. Now when something fails only part of your system goes down and it is easier to identify the culprit.

Dom · Jun 22, 2016

1stNoel said:
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.

Okay... I recently had an experience with just such a problem....

I don't understand why you would feel the electricity in only certain areas. If the tank is electrified, you feel it anywhere in the tank. For example; I had my 300 watt heater rupture in the sump and I felt it in the display tank when I put my hand in while bracing myself on the iron stand. OUCH!

If the problem is an intermittent one, I am inclined to think it is something on a timer (lights) or sensor (heater).

A very wise man on this very site once said to me: "Go DC." A considerably more expensive option, but I've already begun transitioning to. As items fail, I upgrade to DC versions of the item. In the mean time, perhaps you should consider a grounding rod in the sump.

Where grounding rods are concerned, there have been spirited debates here on the subject, both for and against. I chose to use a grounding rod until my DC conversion is complete.

Think of it this way: When you get that voltage spike of 48+ volts, your tank is like a 48 volt battery. When you put the grounding rod in, it becomes a DEAD 48 volt battery. Remember voltage is pressure. You can't have current without voltage.

Just my point of view.

redfishbluefish · Jun 22, 2016

@Dom, no problem using a grounding probe if in conjunction with a GFCI. Without the GFCI, you potentially create current in your tank, and that's what kills. Your battery analogy is backwards. Without the probe, your tank is like a battery sitting on a table....no flow of current. By putting in a ground probe, you've now developed a path for electrical flow (ie current).

ThePapa · Jun 22, 2016

Dom said:
Okay... I recently had an experience with just such a problem....

I don't understand why you would feel the electricity in only certain areas. If the tank is electrified, you feel it anywhere in the tank. For example; I had my 300 watt heater rupture in the sump and I felt it in the display tank when I put my hand in while bracing myself on the iron stand. OUCH!

If the problem is an intermittent one, I am inclined to think it is something on a timer (lights) or sensor (heater).

A very wise man on this very site once said to me: "Go DC." A considerably more expensive option, but I've already begun transitioning to. As items fail, I upgrade to DC versions of the item. In the mean time, perhaps you should consider a grounding rod in the sump.

Where grounding rods are concerned, there have been spirited debates here on the subject, both for and against. I chose to use a grounding rod until my DC conversion is complete.

Think of it this way: When you get that voltage spike of 48+ volts, your tank is like a 48 volt battery. When you put the grounding rod in, it becomes a DEAD 48 volt battery. Remember voltage is pressure. You can't have current without voltage.

Just my point of view.

It is the amperage that kills, 55 milliamps is considered to be the threshold, not the voltage be it AC or DC power. Yes a 12 volt DC car battery can shock you under the correct conditions. Test a new 9 volt battery on your tong if you need convincing.

Tori · Jul 26, 2016

Dom said:
Okay... I recently had an experience with just such a problem....

I don't understand why you would feel the electricity in only certain areas. If the tank is electrified, you feel it anywhere in the tank. For example; I had my 300 watt heater rupture in the sump and I felt it in the display tank when I put my hand in while bracing myself on the iron stand. OUCH!

If the problem is an intermittent one, I am inclined to think it is something on a timer (lights) or sensor (heater).

A very wise man on this very site once said to me: "Go DC." A considerably more expensive option, but I've already begun transitioning to. As items fail, I upgrade to DC versions of the item. In the mean time, perhaps you should consider a grounding rod in the sump.

Where grounding rods are concerned, there have been spirited debates here on the subject, both for and against. I chose to use a grounding rod until my DC conversion is complete.

Think of it this way: When you get that voltage spike of 48+ volts, your tank is like a 48 volt battery. When you put the grounding rod in, it becomes a DEAD 48 volt battery. Remember voltage is pressure. You can't have current without voltage.

Just my point of view.

How's that ground probe working out? I'm having the exact same issue that you were, same voltage and everything. My reading also goes from around 48v to practically 0v when I unplug my ups battery backup. I think I'll probably end up using a ground probe too wo I wanted to see how it's working for you. The funny thing is, my fluke 117 has a low impedance mode for driving out ghost voltages and I read less than 6v when I have it on that setting. It's probably similar to using an analog volt meter. So it looks like the 48v I'm reading isn't a real voltage. The only reason I still want to try to fix this is because I think what ever voltage is there is really messing with my PH probe.

Dom · Aug 9, 2016

The ground probe is working out fine. Solved the issue of voltage in the tank. Although, some will point out that I have created current in the tank by adding the probe.

It's a matter of preference.

Tori · Aug 9, 2016

Dom said:
The ground probe is working out fine. Solved the issue of voltage in the tank. Although, some will point out that I have created current in the tank by adding the probe.

It's a matter of preference.

Thanks for the update. You can always measure the ground probe to see if there is any actual current flowing through it. I measured 0 amps flowing through the ground probe I installed so I'm pretty comfortable with it. I use to due electrical work so luckily I had one of the those clamp on amp meters lying around. I also checked with the amperage function on my DMM to be sure.

cracker · Oct 11, 2017

Alright, Let me say I know nothing about voltmeters I want to check a power head I "suspect" of leaking juice. So I get the blck in ground red in the water no problem there. So looking at the face of the meter I have
(long story) The only settings I see for AC ,one says 750 acv the other 200 acv. Can I use one of these settings? It's no big deal I just want to know if this power head will still safely push water for me. Thanks