Electrical Q

Delphinus · #1 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 · #2 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 · #3 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 · #4 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.

christyf5 · #5 03-20-2010, 08:59 PM

I plugged the pump into a bathroom GFCI and it tripped, guess the pump is done. Anyone need a mag7 impeller?

mike31154 · #6 03-20-2010, 09:06 PM

Oh no, not yet!! You need to liberate the smoke from deep inside of that bad boy first, ha ha.

christyf5 · #7 03-20-2010, 09:07 PM

Quote:

Originally Posted by mike31154

Oh no, not yet!! You need to liberate the smoke from deep inside of that bad boy first, ha ha.

Lance · #8 03-20-2010, 10:39 PM

Quote:

Originally Posted by mike31154

Oh no, not yet!! You need to liberate the smoke from deep inside of that bad boy first, ha ha.

Good one Mike! I love it!

Delphinus · #9 03-20-2010, 10:52 PM

Quote:

Originally Posted by outacontrol

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.

Whoa there dude. Please be assured I am not mocking you. Not in the least. In fact rather the opposite, I am trying to use your electrical knowledge in an effort to better understand something I saw. I think your issue is the fact I asked if if it's hard to say. I didn't mean that as mockery, I really meant that at face value - is it hard to say if the static discharge was responsible for a GFCI trip? The reflector was most assuredly grounded, so the zap of the static absolutely did travel down the ground wire. I was merely asking if it was a possibility that GFCI's could be tripped by more than input condition.

Breathe easy my friend. I will buy you a coffee or whatever your favourite equivalent beverage may be one day should we ever meet in person.

How a GFCI works is less important to me than whether they work at all. It was only curiosity on my part.

At any rate however ... regardless of how a GFCI trips, a pump shouldn't trip the GFCI. Now that it's confirmed that the pump itself seems faulty (ie., confirmed trip on a different GFCI) I'm afraid the end result for Christy is that she needs to replace her pump.

Sorry Christy. FWIW, I had to garbage can a couple mag drives too over the years for the same reason. It's too bad, they are otherwise really reliable workhorses.

DiverDude · #10 03-21-2010, 12:01 AM

*sigh* TWO errors in one post....what WILL I do with me ?

First, I stand corrected by outtacontrol. How I described the function of the GFCI was what had been taught to me by someone who should know better (an electrical engineering professor). However, schematics trump credentials and I now know better -my apologies for the mis-information !

Second, someone give a free frag to Gary for paying attention. He is correct, Neutral is the larger blade of course and I need to type slower or think faster. More mis-information; more apologies -only this time I can't blame anyone but myself.