120v outlet suddenly started reading 240v?

Reply

  #1  
Old 12-11-17, 12:26 PM
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 2
Received 0 Votes on 0 Posts
120v outlet suddenly started reading 240v?

Good morning all and thanks in advance for any help on this!

Background: A few weeks ago, I woke up to our refrigerator constantly power cycling. I thought it was the refrigerator reaching its end-of-life, so I called in an appliance repair tech to take a look. He wasn't finding anything visibly wrong with the refrigerator, so he tested the 120v outlet that it was plugged into and it was reading 240v. "Well there's your problem!"

What I've found: I flipped the breakers to the kitchen and started investigating. We've been in the house for about 5 years and this was the first time I was seeing how the electrical was laid out. Relevant to this issue:

- Red, Black, White, and Ground wires coming into box from panel.
- White is shared between two circuits.
- Black and one branch of White go to line on 20A GFCI outlet that feeds into 5 outlets down the wall.
- Red and other branch of White go to outlet that refrigerator is plugged into.
- The GFCI outlet tripped, I was able to reset it once, it tripped again and will not reset.
- With power to the GFCI outlet ON, the White wire connected to the tripped GFCI outlet is hot (which, when shared with refrigerator circuit, produces the 240v).
- I tried simply replacing the GFCI outlet with two different new ones - which arrive already tripped - and the same conditions exist. I cannot reset the new GFCI outlets and the neutral wire is hot.

What I've tried:
- I isolated the GFCI outlet from downstream outlets, same conditions.
- I isolated the line in from the refrigerator outlet, same conditions.
- I replaced the tripped GFCI outlet with a regular 20A outlet and that seemed to resolve the problem. White wire stayed neutral, all outlets showed 120v.

I installed the new GFCI outlet exactly the same as the old one had been installed, which had been working fine for years. I don't understand why the hot neutral goes away with a regular outlet, but returns with the pre-tripped new GFCI outlet.

Before I call in an electrician, just wanted to see if I'm missing something simple here.

Thanks again,

Jason
 
Sponsored Links
  #2  
Old 12-11-17, 01:26 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,997
Received 40 Votes on 35 Posts
You have lost a neutral connection somewhere in the circuit. You need to find it before the magic smoke comes out of anything plugged into that circuit.
 
  #3  
Old 12-11-17, 01:54 PM
Member
Join Date: Feb 2014
Location: USA
Posts: 2,104
Received 0 Votes on 0 Posts
I find it hard to believe the fridge was plugged in to 240V. Do you have a voltmeter ?
 
  #4  
Old 12-11-17, 02:13 PM
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 2
Received 0 Votes on 0 Posts
Yes.

Both the appliance repair tech and I independently tested the outlet and it showed 240v (guessing the sum of the hot Red wire and the hot Neutral wire feeding into it?). When I only have the refrigerator breaker on and not the GFCI circuit, it correctly reads ~120v. When I have both breakers on with a regular outlet installed in place of the GFCI outlet, it correctly reads ~120v.

What's odd is that it happened suddenly, not tied to any visible changes in the house electrical setup.
 
  #5  
Old 12-11-17, 04:32 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,592
Received 316 Votes on 290 Posts
I would start by identifying every outlet on that circuit. Then check each outlet. The three light plug in outlet testers are good for this as it will quickly tell you if you have a open neutral. If part of the outlets on the circuit test OK and others have a problem the last good outlet and first bad one is a good place to start looking.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: