electric wire

[Scouter]

I need to run a single wire from a service panel down to a light switch. When the original electricians ran the wire to the switch they only ran the black wire. They want me to replace the wire with a timer so they can set it to, say, 15 minutes, to allow them to get to their cars at night. I found the switch to do the job, but it requires both the black and white wires. I was hoping there was some alternative to running conduit.

[TDKPE]

Sounds like a switch leg to a switch. A mechanical timer doesn’t require a neutral.

Like this one: https://www.lowes.com/pd/intermatic-20-a...gICivD_BwE

And this one (same, but from Amazon): https://www.amazon.com/Intermatic-FD60MW...9203&psc=1

And there are others.

[Scouter]

Sounds like a switch leg to a switch.  A mechanical timer doesn’t require a neutral.

Like this one:  https://www.lowes.com/pd/intermatic-20-a...gICivD_BwE

And this one (same, but from Amazon):  https://www.amazon.com/Intermatic-FD60MW...9203&psc=1

And there are others.

Yes, but for what they want to do a mechanical won't work, has to be one of the electronic ones. They want the timer, but to also be able to keep it on until turned off.

[TDKPE]

Yes, but for what they want to do a mechanical won't work, has to be one of the electronic ones. They want the timer, but to also be able to keep it on until turned off.

Use one with a "hold" position.  15, 30, or 60 minute versions available.  

https://www.amazon.com/Intermatic-FD30MH...B003A5CQ4A

https://www.intermatic.com/en/timer-cont...rs/fd30mhw

I like blackhat's suggestion though, especially if it will be turned on and off a lot with the switch.  Save the timer for when the timer is actually needed.  But you'd need a two-gang box.

[Scouter]

Use one with a "hold" position.  15, 30, or 60 minute versions available.  

https://www.amazon.com/Intermatic-FD30MH...B003A5CQ4A

https://www.intermatic.com/en/timer-cont...rs/fd30mhw

I like blackhat's suggestion though, especially if it will be turned on and off a lot with the switch.  Save the timer for when the timer is actually needed.  But you'd need a two-gang box.

I like that one! Thanks! ?

[blackhat]

So parallel a mech timer to a normal switch. Either will turn it on but both need to be off to kill it. Easy peasey in a 2 gang box.

[srv52761]

Sounds like a switch leg to a switch.  A mechanical timer doesn’t require a neutral.

Like this one:  https://www.lowes.com/pd/intermatic-20-a...gICivD_BwE.....

And there are others.

So parallel a mech timer to a normal switch. Either will turn it on but both need to be off to kill it. Easy peasey in a 2 gang box.

Yes, I would suggest one like this.

[attachment=16451]

We installed a mechanical timer in a restroom to control the exhaust fan (custodians continually forgot to turn them off at night) similar to the one TDKPE posted.  It got twisted too far and would't wind down.  The one with the knob and metal cover plate allowed me to drill a hole and insert a #4 screw at the 8 hour mark so it couldn't be over wound.

[Wild Turkey]

I'd go with a motion detector instead of timer.  Somebody might be running late, etc.  

Works in my garage

[Phil Thien]

Well as long as we're sharing opinions, I'd switch to an LED lamp that costs next to nothing to operate, and never turn it off.

[joe1086]

I just installed a motion sensing light switch. Doesn't need a neutral, runs off the black wires and ground. It's in the garage...turns 6 cosco shoplight LEDS on when a car or person enters. Turns off 5 minutes after no motion detected. Turn off time can be adjusted. Lutron brand, about $20 I think...