Electrical Wiring in the Home/Wiring a timer switch


Hello,  I am replacing an in-wall timer switch and wanted to use the Honeywell RPLS730B. The current wiring looks like end of run as I have three wire coming in and nothing going out. This timer requires a neutral and I have a neutral coming in.
I was reading the instructions online for this timer before buying it and had a question.
The instructions say not only that you need a neutral, but specifically that This Switch Cannot Be Used If There Are Not At Least 2 White Wires Joined By A Connector Inside The Electrical Box.
As this is end of run I only have the one white wire.
My question is electrically does that make sense that this could possibly not work with one white wire? Wouldn't this still work with the one white wire or could that really make a difference?
I just wanted to understand electrically if this could matter before buying it.
Thank you very much.

Hello Scott. Electrically that will not matter at all.  The more important question is...Why is the box wired that way?  It would be unusual to have an end run with a neutral in it as you described.   From your description it sounds like you are looking at a 3-way switch.   A 3-way switch is a control system that turns a light on from more than one location.  If you have two switches that controlled that light, the timer you have will not work.  If you only have a single switch and truly have a neutral you will be fine.   Good luck!
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Electrical Wiring in the Home

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Bill Lutz


Any questions about being an electrician or doing electrical work. I can help advise people on their wiring needs, what kind of outlets and switcher to use, explain what an electrical service is and how their breakers work. I can also help them with their lighting needs. . I CAN HELP YOU UNDERSTAND WHAT YOUR LOOKING AT.


My Father apprenticed to his Father-and I apprenticed to mine, repeating an invaluable tradition of child labor and a great place to learn a trade. Beginning at the age of 13, I worked with my dad every weekend and summer vacation in homes throughout Philadelphia repairing and rewiring all levels of residential electrical systems. Studying electrical engineering and earning a degree in architecture has given me a solid advantage in solving the myriad of residential electrical problems. Generation 3 Electrical, Inc. takes pride in every job - building confidence by how we do things - by being prompt, thorough and leaving every job site finished and clean.

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