Electrical Q

Delphinus · #1 03-20-2010, 06:25 AM

Cool, thanks. So, question though, why would it have tripped on the static discharge on the ground line? Does that make any sense to you? Sorry, just trying to understand why that happened. (BTW, sorry for the hijack, Christy..)

outacontrol · #2 03-20-2010, 06:50 AM

Hard to say, was the lights plugged into the GFCI? was the cord for the lights a 3 prong or 2 prong and was id a DIY or brand name bought fixture?

Chase31 · #3 03-20-2010, 07:17 AM

well if you work up the static and it sends it down the "Neutral" wire it could set off the gfi, a static shock is around 5 Amps, so it could set it off

Doug · #4 03-20-2010, 01:37 PM

Christy if you remember the time I had the leak in the stream pump that caused the arc from the halide fixture to my head,

, it never tripped out a standard plug but tripped the gfi plug in. I could also measure that leak with a meter from my tank to ground.

muck · #5 03-20-2010, 01:43 PM

Had a Mag 3 pump leak current on me.
Found out when i went to adjust it while it was running in my saltwater mix bucket with my hand. BAZAPP!!

christyf5 · #6 03-20-2010, 04:04 PM

I didn't notice any zaps when I put my hand in the water but I wear crocs around the house so I don't know if those would make a difference. The pump runs fine and there are no odd wiring where it attaches to the pump. It was used as a calcium reactor pump for a number of years and has sat around for about 3 years or so doing nothing. This morning I think I might try it in a bathroom GFCI and see if it trips all of them or just the one I want to plug it in on.

As for the GFCI's I think they're all brand new or just a couple months old.

No splashes or moisture on the GFCI its well above and to the side of the tank (plus I inspected it, no sweats or salt creep).

Delphinus · #7 03-20-2010, 06:21 PM

Quote:

Originally Posted by outacontrol

Hard to say, was the lights plugged into the GFCI? was the cord for the lights a 3 prong or 2 prong and was id a DIY or brand name bought fixture?

Does it really seem hard to say? The static charge went down the ground wire because the reflector was grounded. Nothing else was on at the time. No current leaked to the hot or neutral wires. Just the ground. Zap. Ground wire. GFCI tripped despite nothing plugged in was on. So it just seems fair to me it could be a combination of current imbalance between the hot and neutral ("black and white") wires and checking for any potential capacitance or whatever it's called, on ground. Ah well. It doesn't really matter to me. Point is it shouldn't be tripping.

Christy - my suggestion for the easiest thing to try is find another GFCI outlet (eg bathroom plug), turn it on and see what happens. If it trips you know it's not the plug. If it is the plug though then at least that's cheaper than a new Mag7.

But I've had Mag drives leak current after a few years of use. I think they get little microfractures in the housing over time. Not sure the explanation though.

PoonTang · #8 03-20-2010, 07:04 PM

may also be that since you had just done a WC than there were splashes and dribbles all over the place around your sump. If you created a path to ground through a simple dribble down the outside of your sump that may have been enough to let the GFI trip. Give it a try today now that everything is dryed out.

outacontrol · #9 03-20-2010, 07:36 PM

[quote=Delphinus;503726]Does it really seem hard to say? The static charge went down the ground wire because the reflector was grounded. Nothing else was on at the time. No current leaked to the hot or neutral wires. Just the ground. Zap. Ground wire. GFCI tripped despite nothing plugged in was on. So it just seems fair to me it could be a combination of current imbalance between the hot and neutral ("black and white") wires and checking for any potential capacitance or whatever it's called, on ground. Ah well. It doesn't really matter to me. Point is it shouldn't be tripping.

WTF!

IS THERE A REASON YOU ARE MOCKING WHAT I AM SAYING? DO YOU HAVE ANY ELECTRICAL TRAINING?
I helped you when you could not get your 3-way switching working. Not impressed at all.
Did you read any of that link that I posted? A GFCI does not function any other way than I described it measures the current on the 2 current carrying wires (the hot and the neutral that you like to call them). It does not measure or check for current on the bare bonding wire (or ground as you like to call it) at all. Period no questions about it.

mike31154 · #10 03-20-2010, 08:48 PM

I'm pretty sure there's no mocking intended here, he's just posting what happened to him with regard to a static charge. I see that the schematic at the bottom of the page (Neutral Transformer Approach) for the GFI device (from your link) contains a couple of coils which I assume sense the electromagnetic fields of the hot and neutral wires. This signal is fed to an IC which appears to have the function of controlling the relay which trips the device. The circuit is tuned to be quite sensitive so that it cuts the power with only a fraction of an amp imbalance. Any solid state device and inductance coil/transformer is susceptible to a static charge or EMI (electromagnetic interference). I'd say it's entirely possible that a static charge or EMI pulse could trip the device even if nothing is plugged into it. As long as line voltage is present at the input of the GFI device, it is sensing, whether it's actually powering something or not. If you read down farther on the page you linked to, there's a case of lightning tripping a GFI device. So IMO, there are more ways to trip these devices other than the 'designed' imbalance between line/neutral.