Latest Discussions : Electrical & Lighting


06:16PM | 09/07/08
Member Since: 10/17/05
21 lifetime posts
Hi there

I'm having a problem wiring a 24 hr LCD programmable timer switch. I can't find a contact number/help line for the manufacturer...

The SWITCH has 4 wires. Green - ground; Black - Hot line in; Blue - "Black wire to the load"; and White - neutral.

I took the old switch out which is on a 14/2 15A 120V breaker, and controlls 3 outdoor lights. To my surprise, the switch for these 3 lights had a black wire attached to the bottom terminal, and a white wire attached to the top. That's it, nothing else could be seen leaving the box.

I've tried every combination to wire this timer switch it - it doesn't work. The only thing I can think out is the two of the wires on the switch must hook up to one of the wires (black or white) that were initially controlling the circuit on the old switch...

Do you have any ideas? Thanks so much.


10:15AM | 09/09/08
Member Since: 01/09/07
199 lifetime posts
What you have there is a 'switch leg' circuit. Power from the main box goes to the light (one of them), and then the hot wire runes down the black wire of a cable to the old switch, and (when the switch is on) back up the white wire to the light(s). See for an example.

If you new switch requires power directly to it, you will need to change the wiring around and run another cable with power direct from the main breaker box to the location of that switch.


05:11PM | 09/09/08
Member Since: 10/17/05
21 lifetime posts
Hi - thanks for the reply. Things are starting to make sense...

If you have a look at the wiring diagram jpg image, do you see any way I can make this work with running a new cable to supply power direct from the main breaker?


8347 wiring diagram


03:26PM | 09/10/08
Member Since: 01/09/07
199 lifetime posts
You mean withOUT running a new cable from the main breaker box? Sorry, but that is required to make this work.

Actually, you just need power coming into the timer switch box.

You could connect it to another existing outlet or other power source, if that's easier than running a new cable all the way back to the main breaker box. (Watch that you don't overload that circuit, but 3 outdoor lights aren't likely to do that.)

Or you could find whichever one of the 3 lights has the power cable coming into it from the breaker box (probably the one closest to the switch) and run a second cable from that down to the timer switch location, so that you have the power there. That may be easier than running a new cable back to the breaker box.

It all depends on where these boxes are located in your house, and what is easier to get to inside your walls, with the least amount of tearing things up.

You basically need power to come into the timer switch box, so that the timer has power always, to keep time. In the old circuit, only 1 half of the 120V power came into that box, because that was all the switch needed to turn the lights on or off.


02:19AM | 09/12/08
Member Since: 07/22/04
649 lifetime posts
it may be easier to exchange that switch for a programable one that doesn't require a neutral wire to make it work.

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