Electrical Wiring in the Home/3-Way Wiring Question



I'm currently looking to replace an Intermatic EJ500 3-way digital timer with a Honeywell PLS750C digital timer which can be wired for either single pole or three-way. I'm attaching photos of the currently installed EJ500, and the replacement PLS750C hoping you may be able to shed some light as to which wire goes where on the new PLS750C. As you can see in the EJ500 photos, we have BLUE out of the switch going to Black, Black going to another Black, and Red going to White. Based on what you see here, could you give me some guidance as to how I should connect the new switch? Any help would be much appreciated.


ANSWER: The white wire on the Honeywell needs to be connected to a neutral, which you may not have in that box. If you have two white wires connected together and capped off, then you DO have a neutral and just connect the white wire to those.

You will need to see the instructions on the Honeywell to see how to wire it up for 3 way use.  It is labeled line and load. Most likely the black wire goes to the power coming in, and the blue and yellow wires are traveler wires that connect to the other switch.  It also looks like the switch will not work unless it is located at the point where the power enters the system.  That would be only one of the two switches.

In other words, the power wire coming in to power the switches and lights must come in at the box where the new switch is located.  Please also remember that I am making the best guess I can, not having the instructions for the new switch.

---------- FOLLOW-UP ----------

EJ500 Current Wiring
EJ500 Current Wiring  

Wiring Instructions PLS750
Wiring Instructions PL  

Thanks for the quick response. Ok, I have to apologize as I attached the wrong image for the currently installed EJ500 switch. You will now see the actual wiring of the current switch with the image I sent you superimposed for reference. Also, I attached a snapshot of the install instructions for the new PLS750 switch, and my configuration would fall under the first wiring diagram for 3-way install highlighted in red. Also, I forgot to mention, that a red jumper wire which is called out in the instructions is actually installed correctly (from previous install) on the other 3-way switch upstairs.

Hope this helps you.

Thanks so much.

Ok, the whole thing still depends if you have a neutral wire in the box, which I do not see. (unless it is behind the other existing switch) It would be two or more white wires capped off together that do not go to a switch. The new product needs a neutral to work.
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Bob Sponaugle


Just about any home wiring question. (not appliance repair) I have done all kinds of home wiring for myself, including adding a new breaker box, etc. Please, questions from North America only. Please be specific with details.

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