3-way circuit power problem

Discussion in 'The Projects Forum' started by Griffin, Jan 12, 2007.

  1. Griffin

    Thread Starter New Member

    Jan 12, 2007
    3
    0
    I have a 3-way circuit that controls a pair of pot type recessed lights at the bottom of a stair well from the top and bottom. The stairwell itself does not have a light in it, so I am attempting to add one.

    The lights at the bottom of the stair well get their power through a 12/2 wire that branches from a junction box. This 12/2 wire has its black wired to the common (white) from the second switch and the white wired to the white to the switch closest to the power. The wire from the sub-panel is a 12/2 and the wire to the junction box is 12/3, but the wire to the second switch is 14/3. I have access to the junction box but not the recessed lights. The house was already wired this way, I did not mix the wires. I don't know if this is contributing to my problem or not, but I thought it might be useful info.

    I installed a mounting box in the stairwell and ran a 14/2 wire from the second switch to the new box. Previously the second switch had a red and black wires hooked to the traveler poles and the white wire hooked to the common.

    At the switch I hooked my new black wire to the common pole and and the white to the existing common. At the new box, I hooked the light up - black to black and white to white.

    Now the lights all are dim like I am getting a drop in amperage or volts (I don't understand series and parallel well enough to know which). I removed the new light fixture and wired the black and white together and capped the box, the old recessed lights are now working fine, but I do not have my stair light. :(

    What is wrong with what I am trying to do? Does this have to do with series and parallel? Most importantly, how do I fix it?
     
  2. Griffin

    Thread Starter New Member

    Jan 12, 2007
    3
    0
    I realized that last post was a bit confusing, here is the circuit in order: From the sub-panel 12/2 to the first switch (black wired to common pole on switch), white to out-going white around switch- 12/3 from switch to junction box (red and black travelers). At the junction box: a 14/3 red to red and black to black travelers heading to second switch, also a 12/2 heading to lights (black wired to white common from second switch, and the white wired to white common to first switch and back to sub-panel. At the second switch, 14/3 red and black wired to traveler poles of switch. A new 14/2 wire added with black to switch common and white wired to white common of the incoming 14/3 line. The new line is then wired to the a light black to black, white to white.

    The circuit works normaly when the black and white at the new box are attached directly to each other. The circuit experiences a significant power drop when a resistor (light and/or reseptacle) is added.

    Why is this happening?
     
  3. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Griffin,

    It is still difficult to picture exactly what your hookup looks like from the two descriptions that you have supplied.

    It would be very helpful if you could sketch up what you have and post the sketch as an attachment.

    hgmjr
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Remember - that white lead on the second switch is effectively a switched hot lead. You've opened it up and put a light in series with your other lights. Put the new light in parallel with the old lights and you'll be okay. Run the wires from the junction box instead of the switch box.
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Here's what I mean:
    stairway lights 2.jpg
     
  6. wireaddict

    Senior Member

    Nov 1, 2006
    133
    0
    Also, to be safe, since you mixed #14 wires with #12s, make sure the breaker or fuse that feeds your staircase is rated for the smallest wire in the circuit, in this case 15 amps.
     
  7. Griffin

    Thread Starter New Member

    Jan 12, 2007
    3
    0
    Folks,

    I apologize for the confusing description.

    Thingmaker3, I appreciate you pushing through and sorting it out for me. I have a much better understanding of series and parallel - I'm in the process of finishing part of my basement - I think you saved me a lot of future headaches. Much appreciated.

    Wireaddict, good call - the circuit was on a 20 amp breaker - changed it out to a 15.

    Thanks again.
     
Loading...