Outlets switch polarity when 3 way light switch is used.


  #1  
Old 10-08-17, 10:50 AM
M
Member
Thread Starter
Join Date: Oct 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
Question Outlets switch polarity when 3 way light switch is used.

OK, this is a crazy one for me. I live in a hundred + year old house. When I turn on the third floor lights (three way) the polarity changes in all the third floor outlets. It doesn't matter whether I use the second or third floor switch. When the ceiling lights are on the polarity is correct. When the ceiling lights are off the polarity changes to incorrect. Can someone tell me how this can happen, and more importantly, how do I fix it.
 
  #2  
Old 10-08-17, 10:55 AM
P
Member
Join Date: Feb 2016
Location: United States, Virginia
Posts: 1,851
Received 212 Votes on 180 Posts
Seeing how AC current doesn't have polarity I'm at a loss as to what you are talking about.
 
  #3  
Old 10-08-17, 11:00 AM
D
Banned. Rule And/Or Policy Violation
Join Date: Sep 2017
Location: USA
Posts: 516
Received 0 Votes on 0 Posts
Since the house is 100 years old, chances are that some of the electrical work is not original. Try to find where the old meets the new. For example, some of it might be BX & part of it Romex.
 
  #4  
Old 10-08-17, 11:50 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 70,203
Received 2,983 Votes on 2,690 Posts
Welcome to the forums.

It sounds like you are using a non contact tester to check. If that is correct.... put it away and get an analog meter or two probe tester. If you are using a plug-in receptacle tester.... put it away too.
 
  #5  
Old 10-08-17, 11:54 AM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 36 Votes on 28 Posts
Your three-way circuit is possibly using an unlawful scheme that switches the neutral wire. If so, the receptacles are being fed downstream of this unlawful circuit. You would need to re-wire the whole mess using modern cable.
 
  #6  
Old 10-08-17, 03:44 PM
M
Member
Thread Starter
Join Date: Oct 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
Sorry, my bad. Polarity was the wrong word. What is happening is that the "hot" and "neutral" change in the receptacle depending on the 3 way light switch position. I have attached pictures that may explain it better.
 
Attached Images   
  #7  
Old 10-08-17, 04:38 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Received 15 Votes on 13 Posts
We need to know about all the wiring at both 3-way switches and the light. We subsequently need to determine where the power for the light comes in and where the first receptacle is connected. To keep it simple first tell us about all the connections at the switches and light.
 
  #8  
Old 10-09-17, 08:18 AM
H
Member
Join Date: Oct 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
It sounds like the switch is cutting the neutral instead of the hot at one end, and the traveler is making the connection. I had a similar issue in my home; the previous owner made a lot of DIY electrical mistakes like this. You need to identify your line and load and where the switch is fed from the panel. Then make sure the hot (usually black) wire is the one attached to the switch, not the white (neutral).
 
  #9  
Old 10-09-17, 11:27 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 11,154
Received 164 Votes on 147 Posts
Your three-way circuit is possibly using an unlawful scheme that switches the neutral wire.

I've seen this before. No one would have ever known had the 3-way switches not burned up within a day or two.
 
  #10  
Old 10-13-17, 07:04 AM
M
Member
Thread Starter
Join Date: Oct 2017
Location: USA
Posts: 3
Received 0 Votes on 0 Posts
Thanks Guys,
Sorry I've been away for awhile. I'm going to open all the boxes and see what the wiring looks like. Hank8, you are probably right. I'll report back and let you know what I find.
Thanks again!
 
 

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