Homeowner Forum / Construction / November 2005

I need to install parallel switches to a couple of lights. And so you
don't think I mean a common 3-way switch, I want this behavior:

Both on: lights on
A on: lights on
B on: lights on
Both off: lights off

This is just (A OR B) logic.

This application is actually for a horse stall, where one switch is a
timer and the other is for manual use (there is actually a third switch
in series with the timer, to allow turning off the timer as well).

I'll try to explain my current setup (I've already tried this circuit).
I'll ignore grounds, but they are connected at each location properly.

1. I have 12/2 coming from the breaker box 2. The hot wire split and is
connected to both switches 3. Each switch comes out as separate hot
wires (I used red on the main and black on the timer switch) 4. The
neutral, red, black and ground wires are run to an outlet near the
lights 5. The neutral and black wires are fed to the outlet 6. The
neutral and red are run to the first light box 7. The timer is
installed and plugged into the outlet 8. 12/2 is terminated with a
standard plug/ground and plugged into the timer 9. The black from this
(the timer) is connected to the red from the first switch and then to
the first light, and then a black wire runs to the second light 10. The
neutral from the timer and the breaker are connected and then are
connected to the first light, plus it is run to the second light 11.
The second light is connected to the hot and neutral

     - - - NEUTRAL
     ----- HOT
     (VV)  LIGHT
     [ / ] TIMER
     [OO]  GFCI OUTLET

             +------------------------  ----+
             |                        \     |
             |                              |
       +-----+------+        +---------  ---+----+
       |     |      | +---+  |         \         |
     (VV)   (VV)  [ / ]   [OO]                   +---
       |     |      | +- -+  |                   +- -
       |     |      |        |                   |
       +- - -+- - - +- - - - +- - - - - - - -  - +

So my main switch seems to work. However, if my timer and lights are
plugged in (timer switch still off), my main switch trips the GFCI
outlet, but the lights still come on. Of course, this means the timer
is no longer running, and turning off the main switch causes the lights
to go out.

I have a feeling this would have worked with a DC circuit, hopefully
somebody can help!

Adam