Stray Voltage

[kruler]

I have been having undiagnosed issues with coral and I'm reaching for possibilities to eliminate, including stray voltage.

With a multimeter, I think the correct setting is the V~ setting at 200. At that setting with the red probe in the water and the black probe to ground I get 22.6.

I also tried on the setting with a V and straight solid and broken lines. At 200m it just says 1. At 2000m it says around 1220.

My questions are (a) is the V~ 200 setting the correct one to use; and (b) if so, is 22.6 a cause for concern?

Thanks in advance.

 

[DiefsReef]

I think post#11 in this thread should help you out..
https://www.reef2reef.com/threads/testing-for-stray-voltage.751113/

 

[NeonRabbit221B]

You want the squiggles as that is AC voltage. You should check for stray current by switching the probes over. 22.6V is not high (IMO) but you can check and see if its a single piece of equipment by unplugging each and rechecking. ICP test?

 

[kruler]

I think post#11 in this thread should help you out..
https://www.reef2reef.com/threads/testing-for-stray-voltage.751113/

Thanks. That post says to set multimeter to 120AC. Mine does not seem to have that setting. I must have skipped the day that everyone learned about AC/DC, volts, ohms, etc.

 

[DiefsReef]

Thanks. That post says to set multimeter to 120AC. Mine does not seem to have that setting. I must have skipped the day that everyone learned about AC/DC, volts, ohms, etc.

I always get confused as well. Thats why I tried to find other posts that have the info.
Like @NeonRabbit221B stated above I think its the squiggle line or wavy line

I googled this..
Turn the dial to ṽ.

 

[DiefsReef]

oh and mine dosent have 120 either, just 200 and 500 V~

 

[kruler]

So I pulled the heater out of the water and the reading immediately went from 23v to 15v. Is this normal? Should the heater be leaking any voltage into the water? It is a cobalt neotherm that is less than a year old.

 

[nereefpat]

Heaters are common culprits to leak voltage, actually the most common. They could also possibly leak other things into the water if the seal is compromised.

 

[kruler]

For others reading this down the road, I called Cobalt and they said 8 volts is normal and expected and any electrical device you put in water will leak some volts into the water. I will probably still swap it out for peace of mind.

 

[NeonRabbit221B]

There is something called inductive voltage and 8V from a heater isn't even high. You are looking in the wrong area bud. When I had a voltage issue it was 85V and I could feel it.

 

[nereefpat]

For others reading this down the road, I called Cobalt and they said 8 volts is normal and expected and any electrical device you put in water will leak some volts into the water. I will probably still swap it out for peace of mind.

That is not true at all. Leaking voltage is dangerous, and not normal. Some induced voltage is expected, especially with pumps. I'm not sure how much is common for heaters, although I would expect it to be really low.

Are you using a GFCI?

 

[NeonRabbit221B]

Old post from our resident electrician

https://www.reef2reef.com/threads/stray-voltage-and-acceptable-levels.291622/post-3550252

 

[kruler]

That is not true at all. Leaking voltage is dangerous, and not normal. Some induced voltage is expected, especially with pumps. I'm not sure how much is common for heaters, although I would expect it to be really low.

Are you using a GFCI?

The wall outlet everything is plugged into is not a GFCI outlet but the breaker that feeds that outlet is arc fault protected. I do not know if that would have the same practical effect. In any event, I know I should replace the outlet with a GFCI.

 

[nereefpat]

The wall outlet everything is plugged into is not a GFCI outlet but the breaker that feeds that outlet is arc fault protected. I do not know if that would have the same practical effect. In any event, I know I should replace the outlet with a GFCI.

AFCI won't necessarily trip in a ground fault situation. Faulty equipment might trip an AFCI in certain situations.

If you can use a GFCI, and it doesn't trip, then I would ignore the voltage reading.