Trouble Shooting help

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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
CO, remember that receptacles are wired daisy-chained. It's a 50/50 chance that the bad connection is in a working receptacle. It's either in the "last" working one or the "first" dead one.

You can also turn on or plug in a light where the power is out, and have someone watching it while you wiggle receptacles, both working ones around the dead area, and the non-working ones.

If MB recep is end of line put a jumper beween hot and neuttral and check continuity on other bedrooms.
I wouldn't recommend that; the intermittent may reconnect while it's jumped.
 
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GUNNING

Senior Member
Loose or cooked

Loose or cooked

I think its in the master bed room. Its the one place where the outlets work except one. I find its the working outlet that is opening the crt especially if they are quick wired. Also, the neutral and ground can be ohmed out to see if its an open ground or hot. Third, look at the ceiling fans and switches. Might be loose wire nut.
 

e57

Senior Member
I have been in similar situations....found a broken 'hot' in a junction box in one situation and a loose wire on a receptacle that 'Johhny home owner' put in in another situation. This situation did not just happen out of the blue...something or someone caused it.
Burned splices and back-stabs happen over a very long time....
 

zappy

Senior Member
Location
CA.
Pull the GFIs on the older models the receptacle will work but the load side will be dead,if walk in closet look for a receptacle.If MB recep is end of line put a jumper beween hot and neuttral and check continuity on other bedrooms.

So the GFCI test button works fine and everything but the load side is dead? Never thought to look at that.
 

220/221

Senior Member
Location
AZ
I can't believe you left without tracing down the problem.

1. Map the circuit in your head and use some logic to determine the cable route.

2. Is the second half out? Look in the first bad recep or the last working one.



I started my career wiring houses so I was troubleshooting in a matter of weeks. Once you know how basic resi wiring is installed, it's pretty simple.....until someone starts messing with the system.

I had one today that would have been simple if the receps were accessible. First one was behind a big bed with drawers under it that I had to take apart...not there. Second one was under a built in desk with a 12" wide x 30" tall opening. Shoulders wouldn't fit and I couldn't lay on my stomach to reach in so I had to lay on my back/side and work upside down.

Like about 40% of resi circuit outages, it was a failed backstabbed connection.
 
Yes, I left without finding the problem. This wasn't a paying customer, it was neighbor/friend that gave me a call on a Sunday night. Relieved!

What I found was a little odd. Like I stated before, I checked all the breakers and all were working properly (voltage on load terminal). So I concluded it must be a broken connection. The panel schedule was of no help, so I ended up narrowing it down to 2 breakers that were serving the upstairs. I opened one of the breakers and checked for continuety between the hot terminals from the known working receptacles to the non-working receptacles to figure out which circuit it was. So once I knew it wasn't the first breaker, I concluded it was the second breaker. I opened that second breaker and the hall lights went off (no big deal right). I found a light switch behind a dresser, once I opened it up I saw that the ground wire was in contact with the switch terminal screw. I lifted the ground wire off the screw and poof problem solved. All is working.

But, why wasn't the breaker tripped? I had a line to ground fault but half the circuit was still functioning, whats up with that? Anyway, problem solved, at least so far as power restored to the upstairs. Now I plan on replacing the circuit breaker, any ideas what else it could be?
 

e57

Senior Member
I found a light switch behind a dresser, once I opened it up I saw that the ground wire was in contact with the switch terminal screw. I lifted the ground wire off the screw and poof problem solved. All is working.

But, why wasn't the breaker tripped? I had a line to ground fault but half the circuit was still functioning, whats up with that? Anyway, problem solved, at least so far as power restored to the upstairs. Now I plan on replacing the circuit breaker, any ideas what else it could be?

I'm just not buying it....

You TOUCHED the problem but didn't see it. i.e. You wiggled or jiggled a loose, resistive, or arching connection in a splice or device - just enought to restore power - for the time being - the problem will come back sooner or later....

As for the ground wire - if it had been touching a hot terminal, it either would have shorted, arched, burned, or that ground is open... The breaker IMO in a situation like that - is fine. If it had shorted and the CB held on a circuit properly connected - the house would be on fire.

First re-think about that ground wire... Was there evidence of a short there? Arched metal, over-heated plastic - smell of smoke?? If not the connection to ground is open, the terminal was not hot/energized, or it just looked like it was touching it......

Power restored when you messed around in that switch box - did you pull the device out - check splices behind it? Or just shift the EGC away from a terminal - and it came back on - all of a sudden? Pull that box apart, open the hot splices and see if the same type of outage happens to the previously effected rooms... If it does (with the power off) remake all the hots and neutrals and grounds in the box. If it doesn't - keep looking and try to remember what else you touched that day, or if anything else was touched by someone else. (plugging something in???) The loose connection if opened, will re-produce the same symtoms as the previous outage.
 
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e57

Senior Member
Here - Now that the power is restored to the affected area.... Go back over before it goes out again.... Find and shut off the circuit it is on... This will confirm what-else, if anything is on that circuit....

Then make a small floor-plan of the areas that have things that are out - besure to check EVERYWHERE..... Take your time doing this step not to miss ANYTHING!

Then draw the outlets and lighting if any, on the floor-plan.

Then draw a line diagram of the enitire circuit - open all of the splices if necessary to ring it out - be sure you know where each wire goes.

Then sit back for a moment and re-create the original outage on paper.... Put the whole thing back together and test your therory - open the conductor that re-creates the same original conditions - if it does - you have found the problem - if it does not - you missed something and the problem is/was elsewhere.
 

growler

Senior Member
Location
Atlanta,GA
But, why wasn't the breaker tripped? I had a line to ground fault but half the circuit was still functioning, whats up with that? Anyway, problem solved, at least so far as power restored to the upstairs. Now I plan on replacing the circuit breaker, any ideas what else it could be?

I'm with e57 on this, you have an open ground and still have a loose connection somewhere. It could easily be in that switch box if that's all you opened before power was restored.

This is where one of those Ideal Sure Test circuit analyzers does come in handy. A loose connection will give a higher than normal voltage drop so when you see the voltage drop go down considerably you know that you got the bad connection.

The easy way is to just open that switch box back up and remake all the taps and then use a circuit tester and see if the receptacles in that room are grounded. It's good to have all the ground connections made because that breaker should have tripped, plus you don't want a live voltage on the ground wire, bad mojo.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
You know, I don't disagree. Thats a good idea e57, think i'll do that. I appreciate all the help guys.
Good response, and an excellent professional attitude. You'll do well here. :)

Specific point to look at: if the switch box contains three (or more)cables, and stabbing was done all over, the original installer may have use one of the switch's screw terminals and a stab to connect the incoming and outgoing hots together.
 

glene77is

Senior Member
Location
Memphis, TN
Growler,
I have a set of houses to trouble shoot.
Somebody entered each house, and cut one cable.
My task is to trace the circuits, make the splice.
Accessible JB are ok, and the GC will repair the walls.

I have a telephone transmitter/receiver but this project requires something more sensitive (through the walls, depths of 12" maybe).

I have been going through procedures to Trace the Broken Circuits,
and looking into buying a real circuit tracer.

Any suggestions on procedures?
Any suggestions on tracers?

:)
 

e57

Senior Member
Growler,
I have a set of houses to trouble shoot.
Somebody entered each house, and cut one cable.
~~~~

I have been going through procedures to Trace the Broken Circuits,
and looking into buying a real circuit tracer.

Any suggestions on procedures?
Any suggestions on tracers?

:)
Untracable weapons and a good alibi.... A megger graphic TDR and some time.
 

growler

Senior Member
Location
Atlanta,GA
I have been going through procedures to Trace the Broken Circuits,
and looking into buying a real circuit tracer.

Any suggestions on procedures?
Any suggestions on tracers?

:)

For a circuit tracer I would stick with either an Ideal model or an Amprobe.
Don't be fooled by the way Ideal equipment looks ( it really works ).

Links for Ideal an Amprobe at some pretty good prices.

http://www.mytoolstore.com/ideal/ide05-05.html

http://www.testequipmentdepot.com/ideal/wire-tracers/61-958.htm

They also have the AT-2005 at the test equipment depot but I can't get the link to work. For a little over $900.00 it reasonably priced.


As far as proceedure if they cut one cable there is no telling what else they did so you would have to check out the entire house. That's where the Sure Test comes in handy. If a ground is touching a neutral it will show up as a boot-leg ground. Finding a cut cable in a house is not difficult, it can be done with a fox and hound but if you want good tracers for later on you may as well let these people buy them for you if you have several houses to check out you will save enough time to pay for them.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
On the cheap

On the cheap

Growler,
I have a set of houses to trouble shoot.
Somebody entered each house, and cut one cable.
My task is to trace the circuits, make the splice.
Accessible JB are ok, and the GC will repair the walls.

I have a telephone transmitter/receiver but this project requires something more sensitive (through the walls, depths of 12" maybe).

I have been going through procedures to Trace the Broken Circuits,
and looking into buying a real circuit tracer.

Any suggestions on procedures?
Any suggestions on tracers?

:)

I have one of these:

http://www.amazon.com/Gardner-Bender-GET-4110K-Wire-Tracker/dp/B000BO6Y1O

For less than 25 bucks you get a decent device. I have used mine successfully for years to locate open wiring.

The sensor is so adjustable it will pick up a signal almost 10 feet away and then can be attenuated to get within inches of a conductor under test. You can literally trace the path of cable through finished walls with it. When you find that the tracer abruptly stops indicating you have found an open.
 
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