Timers and Light Switch Wiring

By Dave Rongey - Summary:

How to Wire a Timer Switch for Lighting: Lighting Control with Home Controls and Home Automation, Basic Wall-Mount Programmer, Timer Switches and 3Way Switches.

Home Automation and Light Switch Wiring
Electrical Question: I’m trying to replace a single pole light switch with a timer light switch in a box that also has another single pole switch going to another light.

  • The timer keeps zeroing out to the flashing initial setup screen after about 5 or 6 toggles of the other light switch in the box!
  • I have the hot split off to each light switch before it ever gets to that other switch, so really, there is nothing in the timer switch that ever interacts with that other switch and yet, after like 5 or 6 toggles of the other switch, the timer switch zeroes out and blows out all my programming. What gives ?
  • Note that the timer switch has a white wire, black wire, red wire and a green wire, and that this switch box is in the middle of the run for both lights, I believe there are four wires coming into the switch box, white wire, black wire , green wire, and a black wire that is ‘taped’ white.

Background: John, a Homeowner from Langhorne, Pennsylvania.

Dave’s Reply:
Thanks for your electrical wiring question John.

Wiring a Timer Switch to Control Lighting

Application: Wiring a Timer Control Switch.
Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrician.
Tools Required: Basic Electricians Pouch Hand Tools and Voltage Tester.
Estimated Time: Depends on personal level experience and ability to work with tools.
Precaution: Identify the light circuit, turn it OFF and Tag it with a Note before working with the timer switch wiring.
Notice: Installing additional fixture wiring should be done according to local and national electrical codes with a permit and be inspected.
Materials: Make sure the timer switch has the same amperage and voltage rating as the original switch, and is fully compatible with the electrical circuit, the light fixture and the type of light bulbs being used.

How to Wire Timer Switch for Lighting

  • Timer Switches and 3Way Switches
  • Typical timer switches cannot be installed with 3-way or 4-way switches unless they are installed at the first switch position, but even then if one of the other switches is toggled then the switching will be out of sequence so the lights many not come on as scheduled, but there may be a solution.
  • If the light timer is to be installed where there are two 3-ways switches then the second 3-way switch may be wired through or bypassed to enable full control from the time switch only and this will work just fine. Be aware that most time switches require a separate neutral wire connection.
  • Lighting Control with Home Controls and Home Automation
  • Another possible alternative is to install a simple home automation system where a controller may be located in one position and a lighting control module may be installed at the light fixture or in the light switch box.
  • Home control systems such that use the X-10 technology would work fine with this set up and there are other home automation solutions as well.

More about Home Automation and Lighting Applications

Basic Wall-Mount Programmer

Basic Wall-Mount Programmer

  • Home automation is about delivering practical control of your lighting and home electrical devices for your personal lifestyle which provides comfort and control and energy savings.
  • I believe that enabling new technologies to customize and schedule common lifestyle activities performed everyday is beneficial in any home.
  • Simply stated, quality home automation makes life easier. Supervisory Control And Data Acquisition systems are extremely useful, they have been around for years and there are numerous applications for their use, especially with Home Electrical and Automation.
  • Controlling lights with single-button scene control and zone control adds new dimensions to a lighting system, a dimension you can’t achieve with a solo dimmer on the wall.
  • In fact, home automation lighting is one of the most powerful methods Interior Designers use to change moods in a room.

Light Switch Wiring
Light Switch Wiring

  • How to Wire Light Switches  – Diagram 1
  • Fully explained pictures and wiring diagrams about wiring light switches describing the most common switches starting with photo diagram 1.

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Be Careful and Be Safe - Never Work on Energized Circuits!
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FAQs Frequently Asked Questions and Comments

4 Responses to “Timers and Light Switch Wiring”
  1. Dave Rongey says:

    Hi Shiva,
    Could you please tell me more about the floodlight and sensor?
    Is this a motion detector type of light fixture that you have?
    I will look for your info,

  2. munusami says:

    Hi Dave, I am Shiva. I need your help how to wire a halogen floodlight sensor.
    Please help me, Thanks
    Regards Shiva

  3. Dave Rongey says:

    Hi Brian,
    I searched for the Make and Model number for the combination switch that you are referring to and was unable to locate the information. Brian if the switch has 3-way capabilities it would definitely say so on the box and on the wiring diagram. Most dimmer switches are now made so they can be wired as single switch or as one of the two 3-way switches and this is clearly stated on the packaging.

  4. Brian Reed says:

    I have a Greenheck Model GTD #381194 Fan/Light delay off timer toggle switch that I am trying to install in a 3 way application. The directions only show Fan & Light Combination or a Single Load diagram. Can it be installed for 3 way?


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