I don't understand this circuit???

Reply

  #1  
Old 07-26-05, 09:33 AM
Curtis Philip
Visiting Guest
Posts: n/a
I don't understand this circuit???

I used to have an outlet controlled by two 3 way switches but it just stopped working one day. I still have power at the outlet, it's just that the switches no longer control it. Anyway I was replacing the switches because I wanted to change the color and I ran into something I don't understand. Depending on the switch location, I can get all three terminals to be hot. On all my other circuits, it's always just two. I removed both switches and took voltage readings off the wires to see what wires were what. Both switches have 120 volts coming in on the black wire. Why does a circuit have two seperate power sources, but this explains why all 3 terminals on the switch are hot. Would this also explain why my outlet is no longer controlled? I can swap outlets and switches but this is over my head. Thanks for the help.
 
Sponsored Links
  #2  
Old 07-26-05, 10:10 AM
Member
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Received 0 Votes on 0 Posts
If there is a 2-wire "Feed-In" cable at the receptacle-outlet with a "constant" 120 volts acoss the Black & White wires, then there probably is a 2-wire cable extended from the receptacle box to one of the two switch-boxes.

I suggest that as a first-step you determine how the Black/White wires of this cable are connected at the receptacle.If you dis-connect the wire that connects to the Black wire of the "Feed-In" cable, there should be Zero volts-to-Ground at the terminals of the 3-way's.

Good Luck & Enjoy the Experience!!!!!!!!!!
 
  #3  
Old 07-26-05, 10:12 AM
Member
Join Date: May 2001
Location: Dry Side of Washington State
Posts: 738
Received 0 Votes on 0 Posts
Originally Posted by Curtis Philip
I used to have an outlet controlled by two 3 way switches but it just stopped working one day. I still have power at the outlet, it's just that the switches no longer control it. Anyway I was replacing the switches because I wanted to change the color and I ran into something I don't understand. Depending on the switch location, I can get all three terminals to be hot. On all my other circuits, it's always just two. I removed both switches and took voltage readings off the wires to see what wires were what. Both switches have 120 volts coming in on the black wire. Why does a circuit have two seperate power sources, but this explains why all 3 terminals on the switch are hot. Would this also explain why my outlet is no longer controlled? I can swap outlets and switches but this is over my head. Thanks for the help.
One three-way switch should have constant power to it. The second three-way switch has power to it via the two carrier wires from the first three-way switch. Power to the receptacle is supplied from the second three-way switch

Can you tells use how many wires, and color, are present in the 3-way switch boxes?
 
  #4  
Old 07-26-05, 10:13 AM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
What are youy using to determine that the terminals are hot? I suspect that your test method is flawed.
 
  #5  
Old 07-26-05, 10:39 PM
Curtis Philip
Visiting Guest
Posts: n/a
I have three wires coming to each switch plus the ground wire that is connected the the metal box. The wire colors are black, white, and red and on both switches the black wire is hooked up to the common terminal. The test method I use to determine if a wire is hot is I grab the ground wire with my left hand and I then lick my fingers and grab the wire with my right hand that I'm curious about. If I get nailed then I know I have a hot wire. Just joking, I use a volt meter. I touch the black lead to ground and then test my wires with the red lead. I've checked the wires with no switches attached so there should be no voltage on the carrior wires since they are not connected.
I think I'm going to open up the outlet connected to these switches and see what's cooking. Thanks for the help and if you have any more clues, let me have them.
 
  #6  
Old 07-27-05, 09:11 AM
Member
Join Date: May 2001
Location: Dry Side of Washington State
Posts: 738
Received 0 Votes on 0 Posts
Turn off the circuit breaker that feeds the 3-ways. Test for voltage.

http://www.idealindustries.com/tm/Multimeters.nsf


Set your multimeter to the continuity function (measuring resistance). Touch both probes together and see if the needle jumps (deflects).

Place one probe on the the 3-way switch's common terminal screw and the second probe on one of the carrier terminal screws. Operate the 3-way switch and see if the meter's needle deflects (should almost peg out on the scale). Turn off the 3-way switch and see if the needle returns to 0. Repeat for the second carrier's terminal screw and the other 3-way switch.
 

Last edited by thinman; 07-27-05 at 09:52 AM.
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
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: