Stray voltage causing issues in tanks!
- Thread starter islandguy11
- Start date
I am also freaking out at the idea that I have stray DC voltages in tanks which have no DC equipment.
Absolutely.
Absolutely.
Maybe what I'm seeing is not DC at all, but it's AC with 180° clipped off.
I traded my oscilloscope for a Gibson guitar back in 1973 and I'm kicking myself now.
I bet I can get a USB probe and a piece of PC software that will turn my computer into an oscilloscope for about 20 bucks though.
I traded my oscilloscope for a Gibson guitar back in 1973 and I'm kicking myself now.
I bet I can get a USB probe and a piece of PC software that will turn my computer into an oscilloscope for about 20 bucks though.
I'm sure if you went to a decent specialty electrical supply store there you could find some properly fitting GFCI (or RCD) receptables; they would hopefully also have a service person who could come help to install.
Ha ha, I find all of this often plays with my head too -- as just one example for some reason one of my overhead filters is showing stray voltage leaking, but the other one (pretty much same exact set up) on another tank of same size is not showing any. I've been saying "WTF...." a lot recently lol.
I haven't got around to probing the brackish tank yet but I'll bet with all that salt in it it's pretty conductive.
Found some info (actually from a reefer site), where an "Electrical Guru" who seemed to know his stuff replied on the subject of DC testing. Here is the exchange (page reference available upon request; not sure if it's appropriate to post direct links to other aquatic sites):
Question: "I’ve seen the articles that state to test for stray voltage you should set voltage meter to 200 AC Volts, place black probe in ground of receptacle, place red probe in the water and the read meter(after unplugging ground probe in tank). My question is will this setting on the multimeter also read voltage that may be leaking from DC pumps and power heads?"
Answer: "Yup, this setting should work fine. The typical meter won't read the induced voltages from a DC pump very accurately because it isn't a sine wave, but the DC pumps do use a modified AC waveform so it will read on the AC setting."
"DC pumps will not leak DC current. The rectifier converts it to DC but the controller then converts it back to some form of AC. There is no such thing as a brushless motor that runs on DC. They all require some form of AC applied to the stator to get the rotor to turn."
Which actually makes sense as I'm getting small voltage readings when I just have DC pumps plugged in during testing with multimeters on 200 AC volts (about 1.5vac with 1 dc pump plugged in; about 2.0vac when 2 DC pumps are plugged in -- incidentally same numbers I'm getting when measuring other tanks that have 1 DC pump + 1 Sunsun 704 canister filter on AC. Anyway I'll probably be ordering some titanium ground probes next week.
Thx for input Mike -- unfortunately I didn't pay attention too much during Shop or Physics classes at KCHS lol, how is a dedicated earth ground different than a ground probe?
It may Not mbe but it's the one that you plug right into the outlet and stick it right in the tank and so any stray voltage goes straight to Earth ground
When did you attend kchs
