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Check your tank for voltage leaks!!!

hiepatitis

hiepatitis

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Was cleaning my tank and put my hand on the light fixture and noticed a buzzing feeling. Took the other hand out and the buzzing went away. I figured there was a bad device somewhere. Used a multimeter to check the voltage difference relative to ground and found 80V. I didn't believe it and couldn't feel anything in there... that is until I grounded myself and got a good jolt. Turned everything off and measured voltage with each device until I found a Koralia that contributed 65V. Opened it up and found the seal was broken.

Lesson: Just because you don't feel a current doesn't mean there isn't one present. I suggest everyone check their tanks.

Note: You may get about 5V of inductive voltage from each device including lights that aren't even contacting water. This is normal.
 
You might want to add a grounding plug. They sell titanium ones pretty cheap.

My question though : Why did that not trip your GFCI??
It should have.
Inductive voltage will not trip it, but a broken seal will, even with just a few milliamps.
 
I have seen ground probes debated. Some people say that the inductive voltage has no current until you create a ground path for it by adding the ground probe.

Don't know why the GFCI didn't trip.
 
GFCI probably didn't trip because it didn't really go through your body, regardless of how grounded you think you were, there probably was an electrically favorable path in your hand and out another part back into the tank giving you the jolt that you feel. In the past a good hangnail I ripped out, open cut, etc on the finger usually is enough to let me know there's something "leaking" in the tank, and I unplug things until I stop feeling the tingle, granted not exactly the wisest way to do things but hey it works for me :D
 
Some real data on effects of current:
  • Slight sensation in hand: 0.4 mA at 60 Hz AC
  • Painful, but voluntary muscle control maintained: 6-9 mA at 60 Hz AC
    Possible death: 100 mA

Most GFCI's trip at 5mA.
So that would explain why GFCI did not trip - simply not enough current, or it would have done a lot more than tingle.

-----

I use a grounding probe for safety, not really to reduce stray voltages/current.
1) It makes it more likely for the GFCI to trip quickly if there is a short.
Instead of waiting for your body to do the honors of completing the circuit.
2) It protects you from the lights.
What most people do no realize is that a GFCI does not help if there is a short
on the other side of a transformer (ballast). That side is isolated, so you cannot get current mismatch,
so GFCI will not trip if you drop your lights in the tank or get salt creep into the socket a bit.
With a solid ground, the hope is that it will short out and blow a fuse, or trip whatever protection circuits
are built into the ballast.

The downside - you will not notice a slight short, and thus not fix it before it becomes a significant problem.
They need to sell a grounding probe with a current sensor warning light.
 
rygh said:
Some real data on effects of current:
  • Slight sensation in hand: 0.4 mA at 60 Hz AC
  • Painful, but voluntary muscle control maintained: 6-9 mA at 60 Hz AC
    Possible death: 100 mA

Most GFCI's trip at 5mA.
So that would explain why GFCI did not trip - simply not enough current, or it would have done a lot more than tingle.

-----

I use a grounding probe for safety, not really to reduce stray voltages/current.
1) It makes it more likely for the GFCI to trip quickly if there is a short.
Instead of waiting for your body to do the honors of completing the circuit.
2) It protects you from the lights.
What most people do no realize is that a GFCI does not help if there is a short
on the other side of a transformer (ballast). That side is isolated, so you cannot get current mismatch,
so GFCI will not trip if you drop your lights in the tank or get salt creep into the socket a bit.
With a solid ground, the hope is that it will short out and blow a fuse, or trip whatever protection circuits
are built into the ballast.

The downside - you will not notice a slight short, and thus not fix it before it becomes a significant problem.
They need to sell a grounding probe with a current sensor warning light.
Click to expand...

Hmmm.....wondering at what amperage will it send you you flying to the wall? Hey Tony.....you wanna find out? :bigsmile:
 
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