How to Choose the Right Outlet Timer

Imagine never having to remember to leave the porch light on or worry that someone might break into your home when you’re on vacation. Installing outlet timers gives you complete control over when lights and other appliances turn on and off, making it much easier to manage both the efficiency and the safety of your home. To choose the right timer for your needs, it helps to understand what features are available.

Motion Detector

If safety and security are your main concerns, motion detectors can be installed indoors or out to turn lights on whenever someone walks by. These are useful for operating lights in the garage, the entryway and rooms that you frequently go into without a hand free to flip a light switch. Outdoor motion detectors can turn on porch lights or accent lighting to illuminate your path if you arrive home after dark. Lights that come on automatically are a great deterrent to potential invaders as well.

Mechanical Timer Switch

The simplest type of manually operated timer is a dial that you turn to keep a light on for a short period while you’re in a room or outbuilding. When the time is up, the light shuts off to conserve energy. Other manual timers feature pins or a dial that you can set up to turn a light on for a few hours at night when you’re out of town or in the morning before you get up. These timers may be installed in place of regular switches or plugged in to an outlet. Plug strips with built-in timers are also available if you wish to control several lights or appliances with one device.

Digital Timer Switch

If you need multiple programming options for different periods of time, a digital timer is the best choice. These timers cost more than mechanical models but have more features and are touted for their accuracy. Like mechanical timers, they can be installed as part of your electrical system or used with an outlet. Digital timers are good for programming random schedules for lights to go on and off while you’re on vacation, but they can also be used to ensure that an indoor or outdoor light is always on when you come home from work.

Is the existing switch a three-way switch?

The first thing to determine is whether the existing switch that you want to replace is a three-way switch or not. A three-way switch is when two switches control the same light. This is often the case in a long hallway or staircase, where you can control the hallway light from either end.

The options I discuss in this article only cover the case where one switch controls the light, or a “single pole” switch. Three-way switch wiring is more complicated and will require a timer that is specifically for three-way switches. Luckily, most things that you would want to put a timer on, like a porch light, only have one switch controlling them. But, double check to be sure, and note which type you have so you buy the right kind of timer.

Do you have a neutral wire in the switch box?

This is actually the trickiest part of the project, but doing this before you go out and buy a timer can save you the hassle of going back and returning it. Before buying anything, you need to find out if your switch box has the neutral wire available. New homes are required to have a neutral wire, but if your home is old, it might not have it.

To find out, first shut off power to the switch you’re working on by turning off the respective switch on your circuit breaker. Some experimentation might be necessary to find the right circuit breaker switch controls the light. Turn on the light and go through your switches to find the one that controls that light.

Next, unscrew the cosmetic wall plate and put it aside. Once the switch box is exposed, unscrew the switch and pull it out slightly so that you can see the wires that are available inside the box.

You then need to figure out how many different types of wires are available inside that box. The answer will be at least two, since the switch needs a wire coming from power and a wire going to the light in order to work. One of these wires is power (“hot”), and the other goes to the light, or the “load”, as it is called.

The neutral wire is usually white. Note that neutral is different than ground.  The ground wire is often bare copper or sometimes green.

The summary of the four possible types of wires you might have are as follows:

  • AC power or “hot” wire: goes to the existing switch, sometimes red, blue, or black, often bundled together with other wires of the same type, sometimes comes from a cable or conduit with Neutral and Ground wires in it. If you measure the voltage using a volt meter (after carfully turning the power back on at the switchbox), you will find about 115V AC.
  • Power to the light bulb or “load”: goes from the other pole of the existing switch to your light, sometimes black also, usually a single wire not tied to any other wires. If you measure the voltage using a volt meter, you will find 115V AC when the switch is on, and 0V when the switch is off.
  • Neutral: usually white, often tied to other white wires, sometimes comes from a cable containing AC and Ground.
  • Ground: usually bare copper or green, often tied to other wires of the same type, sometimes comes from a cable containing AC and Neutral.

So, the question is, does your switch box only have two types of wires (“hot” and “load”), or does it have a neutral wire as well?

When I opened my switch box, the wires looked like a plate of spaghetti. To make matters worse, many of the wires were covered in white paint so they all looked white. But, after some careful observation and some volt meter measurements, I was able to ascertain that I had all four wires. That was good, because I had already purchased a timer that required four wires!

This was my "plate of spaghetti" that was in my switch box. After careful investigation, I was able to figure out what each of the wires was for.

This was my “plate of spaghetti” that was in my switch box. After careful investigation, I was able to figure out what each of the wires was for.

Don’t chance it like I did! Look at your wiring BEFORE you buy your timer! The packaging or description should say what wires it requires. In my case, the product packaging said “Neutral Wire needed for installation”.  Also, if the timer is not battery-powered, it will need the neutral wire. If it is battery powered, it won’t.

Note that if your switch is a three-way switch, the switch box will have an extra wire in addition to the ones I’ve described above!


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