There are a lot of benefits to using a PIR sensor with your lights.
Having them switch on automatically when they detect movement is handy for outdoor spaces.
In particular, whether it’s to light your way when you’re throwing out the trash or to deter wildlife and intruders.
But do the sensors work with any kind of light, or do you need to limit your PIR sensors to only certain types of bulbs?
A PIR sensor will work with any kind of light, but they aren’t the most effective with certain types of bulbs. They can wear out incandescent and halogen bulbs faster, while CFL bulbs take time to light up, so they aren’t the most effective for a quick response.
Let’s explore in a little more detail:
- How well PIR sensors work with different types of lightbulb
- How you can add a PIR sensor to outdoor lights
- The right way to wire a PIR sensor
Is PIR Sensor Compatible With Any Lights?
A PIR sensor will work with pretty much any light. Essentially, they are a different kind of light switch that triggers itself.
A motion sensor is a light switch in the off position. When it detects movement, it will close the circuit in the same way as if you flicked the light switch into the on position.
Then after a set time, when no more movement is detected, it’ll flick into the ‘off’ position again.
So if the light works with a regular light switch, it will work with a PIR motion sensor.
Still, that’s not the end of the discussion.
Because where a motion sensor is different from a normal light switch is:
- It will turn off not long after it’s been switched on, automatically
- It will turn back on again every time it detects movement
- They tend to be used when you need instant light – e.g., to scare someone off, or when you’re in a dark space outside and want to see any hazards
With those factors in mind, not every type of light bulb is best suited to using a PIR sensor.
They all can be, but some of them have drawbacks.
Incandescent and halogen bulbs work by passing a current through a filament, which heats up and generates light.
That filament will eventually wear out, but it’s not just about the lifespan in hours.
Being constantly switched on and off will also be detrimental to the filament and wear out faster.
There’s no fixed about how much faster, but you will burn through incandescent and halogen bulbs a lot faster if they’re constantly being switched on and off.
Compact fluorescent lights (CFLs) don’t have the same problem because they pass a current through a gas rather than a metal filament.
However, the problem with fluorescent lights is how long they take to ‘warm up’ and reach full brightness.
CFL lights can take anywhere from 30 seconds to 3 minutes to reach full brightness, which is a very long time.
Imagine if you had someone trying to break into your home, and they triggered the motion sensor.
They’d hear the click of the sensor and then see a very gentle dull glow from the bulb.
It’s hardly going to scare them off, and by the time the bulb is at full brightness, they could’ve quite easily calmly walked away or even finished stealing something from outside your home.
LED lights are therefore the best choice for motion lights because they have none of these issues.
The semiconductor won’t wear out in the same way a filament will, and they light up at full brightness instantly.
Can PIR Sensor Be Added To An Existing Outdoor Lights?
If you already have an existing outdoor lighting setup, you can add a PIR sensor.
There are three ways you can do this, two of which are really easy, providing they’re compatible with your lights.
Let’s start with the harder one, though: wiring a traditional PIR sensor into your lighting circuit.
The theory is simple, but the execution can make it difficult.
All you need to do is make sure that you install the PIR sensor into the same circuit as your lights.
How you manage this will depend on how your existing lights are wired up because your wiring might not run close to where you want the sensor to be pointing.
If that’s the case, you may need to re-wire the lights to run a cable to the best place for your sensor.
But if your lighting wires do already run close to where you want the sensor, you’ll just have to mount the sensor in place and then wire it into the circuit.
Make sure you’ve switched off the power before you do anything.
I’ll explain how the PIR sensor should be wired up further below.
Then you’ll need to mount it correctly, which is easy enough provided you have the right tools for the job.
Any drill should work fine in a wooden-frame home, but you’ll want special drill bits if you’re working with brick.
If this all sounds a bit complicated, then consider buying one of the cheaper options:
- A motion sensor adapter
- A motion sensor bulb
Motion sensor adapters (Amazon) can turn any screw-fixture into a motion sensor one.
You remove the bulb, screw in the adapter, and then screw the bulb into the new adapter.
The adapter is the motion sensor and usually has the typical controls for a PIR sensor.
A motion sensor bulb (Amazon) has the PIR sensor contained literally within the bulb itself, so there’s no adapter needed.
It’s just a case of swapping out the existing bulb and replacing it with the new one.
It won’t work for every fixture, though – you need to make sure the bulbs or the adapter are compatible and will literally fit inside the fixture.
But you can’t beat them for simplicity.
How To Correctly Wire PIR Sensor?
There are a few different ways to wire a PIR sensor, but if we start with the simplest one, which is just a PIR sensor and a light.
A PIR sensor has three terminals – live, switch live, and neutral. Some detectors also come with a ground terminal.
You’ll want to wire the mains’ power to live and the neutral wire from the mains into the neutral terminal.
Run the load wire from the switch live terminal, so that’s where you’ll connect it to your lights.
Then you’ll also need to make sure the neutral wire from the light is wired into the circuit, probably using a wire nut to connect it to the existing mains to sensor neutral cable.
The second option for wiring a sensor is if you have it controlled by a mains light switch – when you don’t want the sensor or lights to always be working.
It’s straightforward – just wire the mains power to the live terminal on the switch and then run the wire for the load from the second switch terminal to the PIR sensor.
Then wire the rest of the PIR sensor up as above.
The final option is a little trickier, but it’s worth explaining.
This allows you to override a PIR sensor with a switch so that the light is always on when the switch is in the on position.
You’ll want to run the mains power to the live terminal on the PIR sensor and then run another wire from that same terminal to the 1-way switch’s live terminal.
You wire the load from the PIR sensor’s switch live terminal to the lights but have another cable linking the switch live terminals on both the PIR sensor and the 1-way switch.
With this type of circuit, if you leave the light switch off, then the PIR sensor will control the light.
If you flick the light switch on, there’s always a full connection between the mains’ power and the lights, so they’ll stay on until you switch them off.
PIR sensors aren’t super complicated, but you need to ensure you install them with the right type of light if you want to get the most out of them – and that’s LEDs.
Adding a new sensor into an existing lighting setup can be easy if you’re comfortable wiring up components.
If you aren’t confident, consider some of the easier options of adapters or motion sensor bulbs.
Have you added a PIR sensor to your lights? What type of bulb are you using?