volt drop 117 to 50-70

williamphelps

Member
Location
eureka ca.
Replacing a receptical on neighbors house. When I checked the voltage at the receptical it is 70 volts and at the panel it is 117. Slab house no attic space. Any troubleshooting Ideas?
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
I suggest measuring the voltage between hot and equipment ground, and also between neutral and equipment ground. It could help determine whether the large drop is occuring on the hot or the neutral (or both).
 

tortuga

Senior Member
Location
Oregon
Occupation
Electrical Design
And make sure its a 'known good ground', I have been fooled by an energized ECG in the past.
When chasing hard to track down odd voltage readings in a old house I have used a roll spare roll of THHN from the groundbar in the service as my reference point.
 

WasGSOHM

Senior Member
Location
Montgomery County MD
Occupation
EE
Load down your meter, it could be capacitively coupled "phantom" voltage because of an open circuit. As Little Bill mentioned.

A 100W bulb makes a good test light for this. If the 70 volts can source sizable current, things will get interesting fast.
 

Joe.B

Member
Location
Arcata Ca
Occupation
Building Inspector
Bootleg ground? Nail/Screw damage to neutral? Is this an original outlet or added at some point? No attic and slab means that someone may have gotten "creative" when adding a new outlet. I've seen more than a few of those Pierson homes with the romex running on the roof decking, then the wires get damaged during a re-roof job.
 

williamphelps

Member
Location
eureka ca.
Thanks guys for the brain power !! I traced the wire back towards the panel with a tone generator then traced it from the panel with a volt tick. I ended up being suspicious about the same place. I opened up the wall to find where there had clearly been a fire that no one new about. Thank god for fire retardant insulation. Had to take a break to calm myself as I have watched a family grow up there. Six Romex joints hidden in the wall. Wires joined with Buchannan clamps that were crushed with dikes then shrink taped. Some one clearly thought they were doing a good job. Each Buchannan clamp had become little heaters. Well you guys know the story. By the end of the day, I had uncovered three more hidden joints in the walls. Two of them were at least in boxes, but no covers. All of them hidden in the walls. That's only half of the house!
 

williamphelps

Member
Location
eureka ca.
So here is another thought. Given you can never be sure to catch every blunder from the past on a house like this, what if you changed out the panel to GE and installed the THQL1120AF2s and the equivalent 15s. If there were any other problems you would sure increase your chances of finding them long before a fire? Those breakers have bailed me out of a lot of Headaches in the past including multi wire branch circuits. They are a nice support to a good nights sleep.
 
If you suspect there are more of these "treats" in the walls, a real rewire would be better; otherwise you're chasing mystery AFCI trips and whether it's the end equipment or the in-wall wiring. Consider that most people will just reset the breaker a few times before checking anything else, then they'll blame the arc-fault for being flaky, then they'll try the vacuum/toaster/etc on another outlet, then, etc. Last thing anyone will do is suspect the wiring.

Or, AFCIs here are a board over the large hole in the sidewalk; they cover the problem but don't fix it.
 

williamphelps

Member
Location
eureka ca.
Glad you found those (checking the rest of the house, I hope), but... what's a Buchannan clamp?
Sorry for spelling Buchanan splice caps
If you suspect there are more of these "treats" in the walls, a real rewire would be better; otherwise you're chasing mystery AFCI trips and whether it's the end equipment or the in-wall wiring. Consider that most people will just reset the breaker a few times before checking anything else, then they'll blame the arc-fault for being flaky, then they'll try the vacuum/toaster/etc on another outlet, then, etc. Last thing anyone will do is suspect the wiring.

Or, AFCIs here are a board over the large hole in the sidewalk; they cover the problem but don't fix it.
Slab house no attic. Est is $14,000 to $18,000 (not an option) with 4 kids in college. In addition there are no guarantees the rockers won't find a way to create a new problem. If you AF the circuits you will know if you have any other questionable circuits as well as in the future. I agree rewire is best but it is not in the cards.
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
So here is another thought. Given you can never be sure to catch every blunder from the past on a house like this, what if you changed out the panel to GE and installed the THQL1120AF2s and the equivalent 15s. If there were any other problems you would sure increase your chances of finding them long before a fire? Those breakers have bailed me out of a lot of Headaches in the past including multi wire branch circuits. They are a nice support to a good nights sleep.
Sleep on this. There is no evidence that AFCIs do anything to prevent fires and there is ample proof they do nothing to stop or prevent glowing arcs like what you found. The only useful thing about AFCIs are the ground fault component that sniffs out wiring errors and that is the one thing that has been eliminated by GE.
 

williamphelps

Member
Location
eureka ca.
Sleep on this. There is no evidence that AFCIs do anything to prevent fires and there is ample proof they do nothing to stop or prevent glowing arcs like what you found. The only useful thing about AFCIs are the ground fault component that sniffs out wiring errors and that is the one thing that has been eliminated by GE.
Made a 2 breaker test box with a dual AF breaker in one side and a GFCI in the other. I will quickly test the circuits. The ones that pass the tests will get a new combi breaker and the ones that don't get further investigation. The separate breakers will give me an Idea of what I am looking for. I know the AF/GF breakers aren't perfect, but they are better than nothing. Thanks for the input Dave. It certainly helps to talk some of our decisions over.
 

williamphelps

Member
Location
eureka ca.
If you suspect there are more of these "treats" in the walls, a real rewire would be better; otherwise you're chasing mystery AFCI trips and whether it's the end equipment or the in-wall wiring. Consider that most people will just reset the breaker a few times before checking anything else, then they'll blame the arc-fault for being flaky, then they'll try the vacuum/toaster/etc on another outlet, then, etc. Last thing anyone will do is suspect the wiring.

Or, AFCIs here are a board over the large hole in the sidewalk; they cover the problem but don't fix it.
I like to think of AFCIs as monitors that may not catch everything, but at least something is standing guard.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
Made a 2 breaker test box with a dual AF breaker in one side and a GFCI in the other. I will quickly test the circuits. The ones that pass the tests will get a new combi breaker and the ones that don't get further investigation. The separate breakers will give me an Idea of what I am looking for. I know the AF/GF breakers aren't perfect, but they are better than nothing. Thanks for the input Dave. It certainly helps to talk some of our decisions over.
Your test won't mean much with a dual function and GFCI breaker together. You would be better off getting an AFCI breaker such as a GE or Eaton BR that the GFI function has been taken out. Use that and a GFCI and see which one does better. The way you intend to do it if the fault was a ground fault, both breakers would trip since both are GFCI.
I don't know if you know, or realize, that up until a few years ago, all AFCI breakers had a type of GFI in them. That GFI portion is what was catching the staples driven too tight, neutrals shared, neutral to ground faults, etc. The AFCI part was mainly just nuisance tripping from various items that had motors, such as vacuums, treadmills, etc. I've seen no proof that an AFCI works as we are told they do. Biggest concern is a "glowing" connection such as loose wires at terminals causing a high resistance. AFCI's will not detect those.
 

williamphelps

Member
Location
eureka ca.
Your test won't mean much with a dual function and GFCI breaker together. You would be better off getting an AFCI breaker such as a GE or Eaton BR that the GFI function has been taken out. Use that and a GFCI and see which one does better. The way you intend to do it if the fault was a ground fault, both breakers would trip since both are GFCI.
I don't know if you know, or realize, that up until a few years ago, all AFCI breakers had a type of GFI in them. That GFI portion is what was catching the staples driven too tight, neutrals shared, neutral to ground faults, etc. The AFCI part was mainly just nuisance tripping from various items that had motors, such as vacuums, treadmills, etc. I've seen no proof that an AFCI works as we are told they do. Biggest concern is a "glowing" connection such as loose wires at terminals causing a high resistance. AFCI's will not detect those.
The breakers I am using is GEs dual AF breaker THQL1120AF2 with no GFI circuitry. and a separate dedicated GFI breaker. The tests I am running are 13 amp loaded and unloaded separate tests. The purpose of the separate tests is to give me an Idea of what I am looking for. I appreciate and welcome your input as none of us has all the answers. I like to look at the forum as a think tank.
 

williamphelps

Member
Location
eureka ca.
The breakers I am using is GEs dual AF breaker THQL1120AF2 with no GFI circuitry. and a separate dedicated GFI breaker. The tests I am running are 13 amp loaded and unloaded separate tests. The purpose of the separate tests is to give me an Idea of what I am looking for. I appreciate and welcome your input as none of us has all the answers. I like to look at the forum as a think tank. The spec sheet I have in front of me clearly shows that the THQL1120AF2 has no GFI circuitry making it the most versatile breaker on the market. It does not require the neutrals to be separated making it a dream for saving time on MWBC. I have very seldom run in to any electricians that even know it exists.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
The breakers I am using is GEs dual AF breaker THQL1120AF2 with no GFI circuitry. and a separate dedicated GFI breaker. The tests I am running are 13 amp loaded and unloaded separate tests. The purpose of the separate tests is to give me an Idea of what I am looking for. I appreciate and welcome your input as none of us has all the answers. I like to look at the forum as a think tank.
You're in effect using two GFCI breakers, one being dual AFCI/GFCI and a GFCI only. That makes no sense to me. Why not use a single purpose AFCI with no GFPE circuitry and a single purpose GFCI? That would tell you if there is a fault whether it's a ground fault or Arc fault (even a nuisance trip).
 
Top