Main ground wire problem

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Old 08-01-08, 03:02 PM
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Main ground wire problem

I discovered today that the shielded ground wire coming down from my attic and clamped to the water inlet pipe was getting hot, and actually glowing red at the connection point (the glow was how I noticed the problem). I killed the power and removed the ground for the time being. How can I troubleshoot this, or should I just call the electric company or an electrician? Thanks!
 
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Old 08-01-08, 03:27 PM
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Start by calling the electric company emergency line ASAP. You should also turn off your main breaker until they arrive. This is a serious problem, and disconnecting the wire was not a safe thing to do.

If the power company does not find any problems outside your home, then you need to get an electrician in there soon. Again, do not hesitate on this.
 
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Old 08-02-08, 10:37 AM
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Thanks (following up)

The electric company said it sounds like an internal issue, and recommended calling in an electrician. I spoke to a friend who got hold of his electrician, and he said that leaving the ground wire disconnected temporarily should be safe until he can get over in a few days to diagnose the problem. Does that sound right to you? Your message was kind of ominous, so I want to make sure I don't take unnecessary risks.

I went up into the attic and tracked down where the grounding wire is connected. There is a cable going from the breaker box up into the attic, and this cable is loosely connected (with no wire nut or tape) to the metal-sheathed ground wire, which then runs back down to the water pipe.

Is there any possibility that looseness of this connection could be the culprit, or should there be no heat generated regardless? I just put a tester from the ground wire back to the water pipe, and got a reading of about 4 volts.

Thanks again for any help you can provide.
 
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Old 08-02-08, 10:45 AM
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I am not sure what you are referring to when you say ground. Ground should never carry current. There is no ground between the pole and your house. There is a neutral and this is grounded at one point in your main box and in in-house grounds and neutrals are take from this point.

If something was glowing red, then there is something seriously wrong. I would say if you value your house and your life and you do not understand this yourself then get someone who does immediately.

Yes a loose connection could cause great heating and the glow you are referring to. Tightening the connection should stop the problem but it is dangerous working around live circuits if you do not know what you are doing.
 
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Old 08-02-08, 11:42 AM
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Originally Posted by dsc3507 View Post
I am not sure what you are referring to when you say ground.
Thanks for your response. By "ground," I was referring to the metal-sheathed single wire that was connected to my water inlet pipe on one end, and on the other end connected to a cable in the attic that feeds back into the main panel. From what I gather, that is the "backup" grounding path.

I'm about to begin testing all of my outlets to see if anything shows an open ground. The electrician is out of town for the weekend, so I'm hoping that I can wait until Tuesday with the situation as-is. Do you think that this is potentially a dangerous enough situation to warrant calling another electrician right away? Thanks for your input.
 
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Old 08-02-08, 11:44 AM
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Did your light bulbs get brighter or dimmer ? if so turn off any 240 volts devices like range, electric water heater, electric dryer, central A/C turn them off then call the POCO mention them you have loose netural and they should come out and check their side first.

The only time the grounding wire will carry if have short circuit or open netural if it was glowing red then you have stray current going somewhere.

There are few diffrent way to get stray current going and the list can be pretty long but I will list the most common

loose netural

loose POCO nettural

Loose or broken netual wire from other house or source

there are quite few ways to find stray current and the electrician and POCO crew will have to find a way to stop the stray current

{ Normally this is not a simple DIY project to do the trobleshooting due very tricky sisuation }

Merci,Marc
 
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Old 08-02-08, 12:19 PM
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Thanks, Marc -
Haven't noticed any unusual dimming from appliances. I just found an outlet with reversed hot and neutral. I'm going to try and see if I can correct that right now. Once that's done, do you recommend re-connecting the ground wire that I disconnected, or should I just leave this mess to an electrician to sort out? Getting a bit concerned over the fact that we have thunderstorms on the way. Thanks for your help!
 

Last edited by flukeslapper; 08-02-08 at 12:43 PM.
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Old 08-02-08, 12:44 PM
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If you allready disconnected the EGC [ ground wire to the water pipe }

leave it alone until the electrician come in because for safety reason if you reconnected you can get shock if not carefull.

Just wondering how old the house is because somecase you may have ground wire issue going on and have bad connection show up as well.

Merci,Marc
 
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Old 08-02-08, 01:03 PM
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Hi, Marc -
The house was built in the 50's, so the wiring is not the greatest to start with. I had the old fuse box replaced with a 100 amp panel, but I'd like to have as much of the old wiring replaced as possible. I just ran a tester on some outlets, and here's what I found:
Black lead to grounding slot on outlet - 3.8 volts
Black lead to screw on plate - same.

I'm guessing that's not normal. Any thoughts on this?

I'm still going to correct the outlet with the reversed leads. I'm hoping to survive the coming thunderstorms while I wait for the electrician on Tuesday.

Thanks again for all of your help.
 
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Old 08-03-08, 11:57 AM
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3.8 V between the hot conductor to ground { box } if that the case if you have old BX cable { early style amour cable } then you got some serious issue with grounding In fact they do corrouded or loosen up over the time.

but If you have NM old style it is a 50/50 chance you may and may not have EGC wire in the old NM cable.

That good you are planning to upgrading the wiring in the house.

I know it will take time but you will get there just fine as long you understand the current code.

Just make sure you check with the inspector office for latest update info due the NEC code do change a bit and have some variation realted to the code.

Merci,Marc
 
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Old 08-04-08, 09:57 AM
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Originally Posted by flukeslapper View Post
The electric company said it sounds like an internal issue, and recommended calling in an electrician.
I disagree with their assessment. It sounds like your service neutral is either broken or loose and that all of your neutral current is being diverted through the GEC to your water pipe, into one of your neighbor's houses via the copper water system and out their service neutral.

Or possibly the other way around -- your neighbor may have a broken neutral and his neutral current is diverted into your house via the plumbing and out your service neutral. The fact that your appliances still work with the GEC disconnected makes me lean toward this option actually.

Broken service neutrals can happen on the customer's side of the meter, but it is frequently a power company issue because all of their connections are exposed to the weather and wind and can work loose.

he said that leaving the ground wire disconnected temporarily should be safe until he can get over in a few days to diagnose the problem. Does that sound right to you?
One way to look at it is that it's been okay for who-knows-how long so what's another couple days. Personally, it doesn't sit that well with me. Anything that had enough fault current to glow red hot is a fire hazard for sure.
 
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Old 08-04-08, 06:08 PM
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Originally Posted by ibpooks View Post
One way to look at it is that it's been okay for who-knows-how long so what's another couple days. Personally, it doesn't sit that well with me. Anything that had enough fault current to glow red hot is a fire hazard for sure.

True .,, I know what you mean and what I heard and I did see few plummers if not carefull they get hit pretty good with power going thru the water pipes.

That why some of plummers got smart they bring the jumper cable to bypass the spot where they are working on the pipe.


And for all the readers keep in your mind from time to time check the grounding clamp at the main water valve location over the time it can get corroded or loosen up if they look very funky or really rusted out.

If that the case it will be wise to call the electrician to come out and get that fix due some case it will hold current if get it moveing some reason it get get ya.

Merci,Marc
 
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