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View Full Version : surge protectors, gfci+ sparking grounds, oh my!



dsergison
02-12-2005, 11:32 AM
So, I've pulled some new wire since I'm in the wall doing plumbing anyway, and this new wire is for my 3 new grounded livingroom recepticles for my tv, computer, stereo. (and possibly whirlpool? - it's only 1.25 hp 110v)

anyway, I'm hooking up the ground to what has previously been determined to be my ground terminal. and SPARK! ok, only the tiniest spark. really tiny. what the heck?
it's 60v ac @ .1 milliamp (or so my tester indicates. I go check my outlets and remove the powerstrips for the electronics.

no more spark. a little back and forth and I deduce it's the surge protector leaking to ground.

I buy new protector. SAME THING. I guess that's how they work?

wondering now weather this will work with a gfci outlet on the line. if it will trip it?

Dan

J Tiers
02-12-2005, 12:10 PM
First, that should only happen if you are working on something that is LIVE.

Why would you do that?

Surge protectors do have components which have some capacitance to ground, they may spark when plugged in, etc. UL, CE, etc (all the same now, approx) allow some leakage current.

Should not trip the GFCI, they usually are set for more current, 5 or 7 mA IIRC.

lynnl
02-12-2005, 12:12 PM
The air's pretty dry here in the south now, I was getting some static discharge yesterday (rare for this area). Are you sure that's not what you're experiencing?

Just a thought anyway.

ibewgypsie
02-12-2005, 12:32 PM
Power on the other wires? Ground loose on both ends?

Did you know you are recieving "radio waves" right now? they are coursing throughout your body. Micro voltages are converted from the radio waves. If you are insulated and a "acting capacitor" you will store this energy to the "sparking" point. On a dry day it is much worse because the resistance is much higher.

They say the "ark" was made of a layer of wood, a layer of gold, a layer of wood making it the most powerful capacitor on earth at that time. Sparks could shoot out and kill people who touched it. The priests carried it with long wooden poles.

I kinda suspect you are seeing RF induced static. Does the circuit work? If a isolated wire is laid in next to Hot wires it will charge and hold voltage building to the point where it leaks off, or equal to the other conductors. Thankfully thou current is not there, just a static charge.

Really want to get excited, work in a switchyard surrounded by Live high voltage, everything you touch draws long blue sparks.

David (love teasing ya guys, Off to work on my house)

[This message has been edited by ibewgypsie (edited 02-12-2005).]

Evan
02-12-2005, 02:13 PM
The specs for a garden variety metal oxide varistor as might be used in a power bar is max leakage of 100 microamps. That happens to be 0.1 milliamps. Don't worry about it.

dsergison
02-12-2005, 08:10 PM
yeah it's live. but I'm only holding the screwdriver with one hand http://bbs.homeshopmachinist.net//smile.gif

Evan, you nailed it.

thanks.

J Tiers
02-13-2005, 12:40 AM
<font face="Verdana, Arial" size="2">Originally posted by dsergison:
yeah it's live. but I'm only holding the screwdriver with one hand http://bbs.homeshopmachinist.net//smile.gif

</font>

Arghhh.....not to be a granny / pita, but working on power wiring with it live is *not the best idea*.

When you can either turn off power, or wait until you can, there is NO REASON to work on it live.

We enjoy your posts, don't deprive us of them.........

Evan
02-13-2005, 01:14 AM
Electricians work "hot" all the time. IF you know what you are doing it is safe. Ask David, if he is still with us http://bbs.homeshopmachinist.net//biggrin.gif

Left hand in back pocket.

Personally, I always turn off the power. This isn't always practical if it means the entire office will be shut down. The customer sometimes becomes a bit peevish at that prospect.

J Tiers
02-13-2005, 01:55 AM
The electricians I know do two things.....

1) turn off power if possible.

2) if not possible, they wear gloves up to 10,000 volts or so, above that they use different tools.

Not one of them LIKES working on hot stuff. Without exception, they prefer not to, because hot wires are always there waiting for you to screw up.

Naturally, they have to work hot from time to time, and they do.

I personally work on my electronic prototypes at work. Many times I have to do it while they are hot, because I have to compare waveforms etc during debugging.

Many of the things I am now working on have up to 600 volts of 150 kHz to 800 kHz square waves on parts. These are parts that I have to connect a probe to or otherwise get near. Spike voltages may be 30% higher.

I don't do it when I can avoid it, because it makes no sense.

psomero
02-13-2005, 05:21 AM
<font face="Verdana, Arial" size="2">Originally posted by Evan:
Electricians work "hot" all the time. </font>

i was about to say... i've never seen my dad cut the power to work on anything before.

i guess being an electrician for 35 years gets to your head or something

ibewgypsie
02-13-2005, 06:52 AM
Yes and no.

I was working at Lawson Electrical in Chattanooga Tn. They had hired a young helper, had him on a job in Dalton Ga. He had only been there a day or so. They were working on lights at Shaw INd and the company refuses to allow anything turned off, including lights. The young apprentice was killed while changing out a ballast. The electrician even thou he was a "union brother" should have been arrested. He was in charge and let the inept young man get killed.

ANYTIME YOU work something hot, you have a backup man, to seperate you from the power, to restart your heart, to call someone else who can. You wear gloves if possible, insulate yourself from conducting pathes if possible, *(ladder, dry gloves, dry shoes) Wear glasses or at least saftey glasses since the molten copper blowing out will blind you momentarily with the flash, then of course permenantly with the impact and burns. If it is something you deem too stupid to try, back away.

Taking the ground cable out from over a hot 13,500 vac switchyard was the last thing I refused to do. I tried to calculate the swing of the fiberglass boom (deflection), the weight of the cable (droop), my arm's strength and got a headache.

On the other side, there was this electrician who hired a young man to help him, he stood on one leg, worked on the power hot, didn't get shocked. Then let the young man try. It knocked him silly, as he was laying on the floor trying to regain his composure the old electrician looked at him and said, well, you don't have a wooden leg to stand on do you? http://bbs.homeshopmachinist.net//biggrin.gif

Turn it off, check it with a meter, it only takes a minute, lots shorter than a trip to the hospital to get your heart checked out.

I tell people "technicians don't get shocked" I guess I lie, I got hit a couple weeks ago from something I was sure I had turned off. Surprised, took it for granted.. Ever taste the metallic taste after you get shocked? Is it carterized salvia or blood?

Evan
02-13-2005, 07:55 AM
I was working on an old color TV many years ago. I was talking on the phone to a friend at the time, phone held to my left ear. I reached with my right hand to adjust the horizontal oscillator coil when a spark jumped to my hand from a crack in the high voltage lead to the tube. It went up my arm, across the back of my neck and and arced into the phone. My friend was saying "hello, Evan.. Evan??? " I couldn't answer for about a minute. It was totally stunning. After a while I discovered that my heart was still beating and that I could still breath.

Not recommended.

ibewgypsie
02-13-2005, 12:41 PM
Evan: probably thousands of people have died working on old television sets, unplugged. They store enough energy to kill you quite dead. I never have been hit by them, a ultrasonic cleaner, yes.

A old Airconditioning man, told me he was the smartest electrician in Dalton Ga. I watched him reach into a just turned off 480 inverter with a screwdriver going to short out the capacitor bank, I opened my mouth to speak my displeasure at the act about the time it arced. Blowed about three inches off the screw driver. Seems he had been doing that to air conditioners for about twenty years. Enormous power amounts are stored in them lil capacitors.

Sometimes it is like a snake laying there waiting on the unknowing, or uncaring or careless. All the inverters I have saw have a lil red led showing "charge".

The metal parts added into my body to repair breaks over the years seem to "buzz" when I get charged up. I don't like that. I try to be careful and "never get shocked".

I treat live 480 with the same respect I do a snake.