Stray Voltage help

[jml1149]

With a voltmeter....one probe in the tank water ...the other to ground...on the wall plug...

Also, a cold water pipe if one is available would be a safer route. I get nervous when people stick things into wall outlets. You don't know if it's wired correctly. And to find out would require sticking even more things into wall outlets.

 

[mmcaleer]

Looking forward to hear what you find. I just posted an issue like this myself. I measured 48v in my system. I do NOT get any tingling when I put my hand in. These were my measurements:

Power strip (eqpt plugged in but switched off) = 4.6v
Return Pump = 18.3v
Cobalt heater 1 = 21v
Cobalt heater 2 = 21v
top off pump = 12v
MaxJet 1200 (reactors) = 20v

Yes, I know it doesn't add up but these are the voltages if I only plugged the single item and measured. If I plugged everything in at the same time it seems to settle at around 48v. If I turn off the MaxJet running my two reactors it drops to about 39v.

Mike

 

[Silly clownfish]

I have gone through a similar exercise with my tank. I got a pretty good shock from my sump (across my hand that was touching water and a ground - it tingled for a couple of minutes). My multi-meter read about 80v (I forget the exact amount) I measured each item individual item measured at 1-3v, except on Hydor powerhead that was leaking about 40-50v and both of my Ehiem 150W heaters. Both heaters were at about 15v and were both a little less than 2 years old. On other tanks I have 12-18 year old ehiem/ebo-jager heaters which leaked less than 1v each.

The powerhead got chucked and replaced with a Tunze, which measures at less than 1v

I contacted Ehiem, who basically just asked for a copy of the reciepts and my address and sent me one new heater. I still don't understand why they replaced one, but not both. At any rate the new one also leaked 15v. I am not sure what to do with those. My sump currently measures a little under 40v.

 

[Pete_the_Puma]

So after doing a lot of reading about this it turns out having stray voltage does not really matter, and I am pretty sure anyone who said it was NOT normal has actually never really measured their tank.

It turns out it's the number of AMPs that actually can cause trouble.

Read this thread:



http://www.reefcentral.com/forums/showthread.php?t=1647879




Very informative.

 

[Shivsreef]

Hi!

Regarding the cobalt heaters....
I had two failing within 2 months. Both brand new!
The first one stopped working altogether.
The second burned out yesterday.
I came back home and the whole house was smelling bad! I mean really bad. That was totally strange because the same day the cleaning lady was here and the house smells great after she is finished.

I opens all my windows but the smell would linger.
After passing by the aquarium a couple times I realsed that the smell was coming from there.

Instictevly I checked the temp and it was 20 degrees Celsius.
I smelled the heater and I almost fainted.

What I am saying is check if it is the heaters! I don't trust cobalt at all.
Thank his I didn't lose any live stock and I had my trusty Eihem heater on hand

Never again a Cobalt for me!!

If I'm right cobalt heaters are recently getting a bad reputation as even the King of diy (uarujoey) lost his Rays to his cobalts exploding. Also one of my friends lost some sharks in his indoor pond as a cobalt heater exploded and all black smoke came into his house and also went into the pond.

 

[alton]

Also, a cold water pipe if one is available would be a safer route. I get nervous when people stick things into wall outlets. You don't know if it's wired correctly. And to find out would require sticking even more things into wall outlets.

DO NOT use a water pipe as a grounding means!

 

[theatrus]

And stop worrying about measuring voltage.

 

[alton]

And stop worrying about measuring voltage.

Mostly true because it is current that kills! The worse shock I ever received from an aquarium was from a customer (LFS owners home tank) that was only reading 2 volts, but since he lived in rocky soil his service ground was worthless, plus who ever wired his home placed the grounding and grounded conductors on the same bar in the secondary panel, and it was using his tank as a grounding means. Plus the fact the security company tied a secondary ground to his water pipe up stairs, every time he took a shower he was getting shocked. Grounding probes are not a bad thing because they can help in tripping the GFCI breaker / receptacle versus you getting the shock, but you need to, or pay someone to test your service ground and receptacle grounding first!

 

[alemone]

Grounding your tank water will not solve the problem but create one or you tank. That will enable any stray voltage to create a current. Grounding may prevent you from getting electrocuted but may harm you tank inhabitants. The only solution to stray voltage is to use as best quality equipment as you can, have the equipment grounded if possible and try to keep all things electrical in your sump.

 

[alton]

Do you not think the water running from the sump to the tank will not carry the current? Yes we do need to purchase good equipment, but the only way to keep current out of our tanks is use external equipment, like Ecotech MP pumps. If you slap a pump or a heater in your water column then make sure it is on a ground fault protector and is grounded, or let yourself be the ground and hopefully it trips before it stops your heart. Or your spouse will tell her friends "He had a beautiful tank, too bad he can't enjoy it anymore". Voltage without current is worthless and is not harmful to us. Lamps can cause stray voltage, pumps spinning in you tank create stray voltage. But when your cord gets frayed, heater seal cracks, and you start leaking current is when you have trouble.

 

[alemone]

No, a current won't run from the sump to the main tank as the resistance of that circuit would be too high. If there is any current it would be orders of magnitude lower. I will add that a single electrical item in the main tank should be safe too (for the tank, not for one's hand submerged).

 

[alton]

So you are claiming water is an insulator, not a conductor.
I give up.

 

[alemone]

So you are claiming water is an insulator, not a conductor.
I give up.

Who said that?

 

[theatrus]

Conductivity of 35ppt salt water at ST is about 4.8Siemens/meter, or about 0.2 ohms/meter. Thats... pretty conductive.

If you want to use a ground probe to immediately trip a GFCI when wire insulation breaks down on a mains cord, that is your prerogative. Its absolutely not required.

Attempting to fix any other perceived issues is likely to create more actual issues, as the tale of multiple ground points above shows. Electrical systems are designed correctly for house wiring, and more grounds is absolutely not better (especially if the grounds end up carrying current).