Time Clock and Relay for 4 way circuit?

[larry4406]

Can some one school me on adding a relay/time clock to a 4-way circuit to control lighting?

I have a 4-way circuit controlling exterior lights on the detached garage. None of the timers I have found easily accomodate 4-way circuits.

Any thoughts? I want to retain the local functionality at the existing 3 switches.

 

[Alchymist]

A dpdt relay run off a clock timer would turn the lights on and off. Problem you might run into is that if you manually turn the lights on and leave them, the timer would then turn them off instead of on during the time you want the timer to turn them on. If you remember to leave them in the proper state for the timer to operate, it will work.

 

[Gooch]

Leave the 4 way setup alone. tap off the first switch(constant Hot and Neutral) then run wire from timer to end switch and tap onto the switch leg of the ending 3-way. You won't be able to turn the light off with the switches if the timer is closed.

 

[Alchymist]

Leave the 4 way setup alone. tap off the first switch(constant Hot and Neutral) then run wire from timer to end switch and tap onto the switch leg of the ending 3-way. You won't be able to turn the light off with the switches if the timer is closed.

Actually, if the timer is driving a DPDT relay, you can turn the lights off. The timer acts just like another hand flipping a 4 way switch. The DPDT relay is just another 4 way switch, and the timer flips it back and forth. If the timer has the lights on (relay on for example) and you flip one of the other switches, the lights go out. Then when the timer turns the relay off, the lights will come on.

 

[Gooch]

Actually, if the timer is driving a DPDT relay, you can turn the lights off. The timer acts just like another hand flipping a 4 way switch. The DPDT relay is just another 4 way switch, and the timer flips it back and forth. If the timer has the lights on (relay on for example) and you flip one of the other switches, the lights go out. Then when the timer turns the relay off, the lights will come on.

But with that if the lights are on already when the timer calls for the lights on it will switch the relay and actually turn the lights off won't it? I would assume the OP wants the lights on at a certain time regardless of previous switch position.

 

[Alchymist]

But with that if the lights are on already when the timer calls for the lights on it will switch the relay and actually turn the lights off won't it? I would assume the OP wants the lights on at a certain time regardless of previous switch position.

I alluded to that in post #2. OP didn't actually define how he wanted it to work......with the same relay, it could be wired to turn the lights on at a certain time regardless of other switches, but then the lights cannot be turned off by those switches. OP has to define just what operations he wants.

 

[larry4406]

Hi - thanks for info. To clarify, I only have access to one 3-way switch for wiring modifications, the other 3-way and 4-way are not accessible due to drywall and I am not interested in drywall repairs. Not sure if this accessible 3-way is the "end" feeding the light without checking.

I would like each existing switch to be able to turn lights on or off regardless of timer state. Then the timer will have lights on for a certain period of time. Would like for a local switch to be able to override the timer and turn off the light but the timer circuit would turn it on at the next timer cycle.

 

[wssix99]

Just do a web search for "three way timer switch" and take your pick! You should be able to pop it in place of your existing three way and be good to go.

 

[Alchymist]

Just do a web search for "three way timer switch" and take your pick! You should be able to pop it in place of your existing three way and be good to go.

Not all three way switch boxes have a neutral wire included - so timer will not run.

If it's a simple 3way switch, it will turn the lights OFF if they happen to be on via the other (manual) switch. To achieve what the OP wants the timer switch must have a way to determine if the lights are already on and not turn them off. Getting into logic controller area. And I doubt if OP will be able to do what he wants without access to both switches, and not removing drywall.