Could use a little help

[DesignerMan]

Got a call from a customer who says he had some receptacles not working. When I got there he told me it was (3) bathroom receptacles and the outside receptacle. I checked them each with my DMM and found the following readings:
hot to neutral = 96V
neutral to groung = 24V
hot to groung = 120V
Checked the breaker panel and found everything to be ok- breaker feeding this circuit read 120V.
Then found GFCI receptacle that feeds these receptacles next to panel.
Everything reads fine at this receptacle and it was wired correctly (line and load).
Customer said problem began when he had a remodeling done and the inspector required this GFCI be installed. Said the receptacles did work at one time but soon after stopped.
Note: House was built in 1990's with standard Romex wiring.
Any help would be appreciated- I'm stumped.
Thanks!

 

[iwire]

What are the readings at the panel? Hot to ground, hot to neutral, neutral to ground.

It sounds like an open or high resistance neutral connection.

 

[DesignerMan]

What are the readings at the panel? Hot to ground, hot to neutral, neutral to ground.

It sounds like an open or high resistance neutral connection.

Everything is fine at the panel:
Hot to neutral = 120V
Neutral to ground (terminated to same bar) = 0V
Hot to ground = 120V
The breaker that this circuit is on feeds a GFCI receptacle (at the panel) and everything is fine at this receptacle as well; both line and load sides.
Not sure which receptacle is first after the GFCI. Was thinking of disconnecting receptacles and determining at what point (if any) the circuit is corrected. However, I'd prefer to have an idea as to a cause before do this.

 

[PetrosA]

Since it sounds like voltage is good at the GFI, I would also check your readings off the line and load screws of the GFI to eliminate a bad device as the issue. Then I would check all the devices from the GFI up to see if any have bad connections or a shorted N to G in the box.

 

[ElectricianJeff]

Customer said problem began when he had a remodeling done and the inspector required this GFCI be installed.

The problem is downstream from the GFCI. I would start by looking where the remodeling was done. Almost has to be a neutral as stated.

 

[Rewire]

it is a neutral issue the most likely point of problem is the feed through GFI. Remove the GFI an reconnect the wires and see if it corrects. I had this issue once and it was ion the GFI. If this is not it then its a simple hunt or the next good recep.

 

[DesignerMan]

it is a neutral issue the most likely point of problem is the feed through GFI. Remove the GFI an reconnect the wires and see if it corrects. I had this issue once and it was ion the GFI. If this is not it then its a simple hunt or the next good recep.

Yea, I was thinking a problem with the GFCI possibly, so I took it out of the circuit and everything was still the same. Guess my next step would be to remove some wiring to receptacles to determine which one is first, second, etc..and determine point to point where the problem is located.

 

[kwired]

My first guess is high resistance in neutral conductor someplace, based on your voltage readings.

Make measurements with and without load connected - 100 watt lamp is plenty of load to get necessary results. Even if the lamp does not light up it may change your readings (in fact will change them if there is a bad connection someplace)

If 120 volts to ground remains strong with load connected the hot is good, if neutral to ground raises when load is connected the neutral does not have a low impedance back to source.

Also make measurements to a known good ground and not the EGC at the receptacle(s)

 

[Rewire]

check the outside receptacle. poorly fitting covers can allow moisture to get in causing corrosion.

 

[DesignerMan]

Yea I feel confident now that it is a neutral wiring issue after reading everyone's replies. I also found a DIY forum on a google search where someone had the exact same issue, right down to the voltage reading, and it was a loose wirenut on a neutral.
Thanks for all the suggested troubleshooting tips- I'll use them and let you know what I find.

 

[Fulthrotl]

Yea I feel confident now that it is a neutral wiring issue after reading everyone's replies. I also found a DIY forum on a google search where someone had the exact same issue, right down to the voltage reading, and it was a loose wirenut on a neutral.
Thanks for all the suggested troubleshooting tips- I'll use them and let you know what I find.

i suspect a floating neutral as well.

i'd shut off everything but that circuit, and see what's on it, and unplug anything
plugged in.... and see where it goes south. i'm suspecting the neutral is being
completed thru the ground, possibly in a piece of connected equipment... my
first box i'd open is the last one in the series that works correctly... maybe a bit
of guessing as to how it was roped, but that's where i'd start.....

 

[kwired]

i suspect a floating neutral as well.

i'd shut off everything but that circuit, and see what's on it, and unplug anything
plugged in.... and see where it goes south. i'm suspecting the neutral is being
completed thru the ground, possibly in a piece of connected equipment... my
first box i'd open is the last one in the series that works correctly... maybe a bit
of guessing as to how it was roped, but that's where i'd start.....

Neutral is not being completed at all, or has pretty high impedance anyway, otherwise the receptacles would be (or at least appear to be) working properly to the HO.

 

[Fulthrotl]

.

 

[growler]

Customer said problem began when he had a remodeling done and the inspector required this GFCI be installed.

I find that remodeling is always a "key" word. I would ask who did the remodeling. If it was an electrician that installed the receptacle it's probably a loose connection but if a handyman it could easily be a big old nasty looking flying splice in the wall.

I would disconnect the receptacle that I think is next in line and check resistance from that GFCI to see if there is a bad connection on that neutral. Or they could have just driven a nail through the cable, it happens. :roll:

 

[220/221]

When I got there he told me it was (3) bathroom receptacles and the outside receptacle. Built in 1990's

I could trouble shoot this one over the phone. You know it's the GFCI circuit and there are probably only 5 locations to check. At least, that's the way it was done here in that era. One GFCI recep on a 15A circuit fed all bath and outside receps.

edit: didn't readd all replies. If it's not stock wiring, who knows. But it really can't be that hard to find. Take things apart and follow the path.

 

[DesignerMan]

Just got back from customers home- problem corrected.
It was a neutral wire on a receptacle in a bathroom being remodeled by the HO. The wires were coated in dust and started to burn at one point causing the neutral connection to loosen. Cleaned out the box, replaced the damaged receptacle, and all is good.
Thanks to all who helped me find the issue- greatly appreciated!