Multimeter

[redfishbluefish]

The answer is YES if you like current in your tank and never knowing if you have something leaking voltage.

The answer is NO if you what to protect your fish and coral and identify when you have a problem.

 

[Young Frankenstein]

Bottom line, if I do not have gfci should I or should I not run a ground probe?

If you don't have a GFI the only protection you have is the circuit breaker tripping, and trust me it will not :) what will happen is everything in the tank will be killed. 1 to 2 volts is stray voltage created from the magnetic field from the power heads, it is normal. If you measured 26 volts you have a problem. See above post from redfish :)

 

[Scoly]

Tagging along!

 

[-Logzor]

Thank you for the responses, my white. Return is leaking 12.5 volts, skimmer leaks none, random other pumps leak the rest, including two tunze 6100s, mj 1200, and another small pump. Luckily my MP 60 provides most of the flow and the smaller pumps were for my sump and a reactor. So I shut everything off except for the return and skimmer which brings me down to 12.5. I tested my other eheim which I use to mix salt and it reads 4.6 volts. How much is normal?

 

[-Logzor]

Please excuse typos and strange sentence structure I'm on a smartphone. Dunno why it says my white Lol

 

[redfishbluefish]

Your return is a problem. Change it out.

 

[-Logzor]

I can easily switch them out but the better one is still reading 4.6. Should I just buy a new one maybe?

So.... Before when I had everything running I was hitting 26 v. Does this possibly explain my STN issues on my SPS?

 

[MBG75]

MBG unplug your probe and test your voltage….I guarantee it’s not zero.

You are correct. With the probe out it reads almost 2v.
But with the probe in, it reads 0v and 0.0 amps. So no current is traveling to ground.
I chose to run a probe and GFCI.

 

[redfishbluefish]

But with the probe in, it reads 0v and 0.0 amps. So no current is traveling to ground.

Note that current is measured in a different way to voltage (and other measurements). With your multimeter (VOM) set to AMPS (I), pull your grounding probe out of the water and put one multimeter probe in the tank water and the other on the grounding probe. Read the amps on the meter. (Note that some VOM's require you to put the probe leads into different plugs on the meter to measure amps.)

 

[MBG75]

Note that current is measured in a different way to voltage (and other measurements). With your multimeter (VOM) set to AMPS (I), pull your grounding probe out of the water and put one multimeter probe in the tank water and the other on the grounding probe. Read the amps on the meter. (Note that some VOM's require you to put the probe leads into different plugs on the meter to measure amps.)

It's a clamp on amp meter and the probe is a single wire back to the center screw.

 

[-Logzor]

Ok I swapped out returns and noticed I was still reading voltage. So I cut the return, then the water connect from the sump to the display was severed. I pulled out every wire going into the display....still reading 5 volts. The sump had the exact same reading. How could there still be voltage with no wise in the tank?

So I then unplugged the power strip from the wall. Then voltage dropped to near zero, I tried testing each item in the powers trip and it didn't seem to matter which item was plugged in, the voltage came back each time. What is going on here?

 

[redfishbluefish]

It's a clamp on amp meter and the probe is a single wire back to the center screw.

OK….with clamp-ons you are actually measuring the electromagnetic field created by the flow of electricity (current). To use this, put the ground probe (or ground probe wire), within the circle of the “clamp.â€. Start with scale high and begin to turn down the scale until you see a number.

 

[redfishbluefish]

What is going on here?

Could you have an energized ground? With no wires in the tank, that voltage has to be coming from somewhere, and the ground looks very suspect to me.

 

[-Logzor]

Could you have an energized ground? With no wires in the tank, that voltage has to be coming from somewhere, and the ground looks very suspect to me.

What do you recommend checking to confirm this? I'm not sure what an energized ground is but at this point I won't rule anything out.

When I plug in my checker into the power strip it says open ground. My other outlets read fine though.

How can I fix an open ground? I can barely get back to that outlet becAuse the tank is in front of it.

 

[redfishbluefish]

An open ground means that that outlet is not connected to a good ground. You mentioned it’s a 1949 house, and if this is original wiring, it most likely is BX cable….metal encased wire where the outer metal casing is the “ground.” If it’s been a more recent wiring job, and your code allows, it could be Romex wiring (plastic covered) where the ground is an actual wire within the bundle…..the bare wire.

What I mean by “energized ground” is that wires got crossed somehow and voltage is now being sent up your ground wire.


How do you fix this…..I’d start at the outlet you can’t get to.

 

[-Logzor]

About half of the wiring has been replaced. So I'm guessing a ground didn't get ran for this outlet, however, I believe other outlets on the same circuit are grounded. I can get to the outlet but its an extremely tight space. Is there an easy way to ground it? The water main is nearby could I somehow run a ground wire to it?

 

[-Logzor]

Correction, all outlets on that circuit have an open ground.

 

[redfishbluefish]

FYI…this is not the cause of your tank leaking voltage. However, this “open ground” really needs to be fixed.

It’s great that you know the circuit of outlets. I’d start to look at each one of these outlets/switches to make sure they are wired correctly. This is especially true if you have a mix of Romex and BX wiring. If you’re not comfortable doing this, hire an electrician. Best of luck.

 

[-Logzor]

So what is causing the voltage in the tank when there are zero wires going into it?

Thank you for the advice I plan on hiring professional help to solve the ground issue.

 

[-Logzor]

Btw all of the outlets on that circuit also read as open ground according to my tester.