How to Adjust Motion Sensor Light Settings (SENS, TIME, LUX)
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Most outdoor motion lights have three small dials on the underside of the sensor head. Labels vary, but the functions are nearly universal.
| Dial | Also labelled | Controls |
|---|---|---|
| SENS | Sensitivity, Range, Distance | how far away, and how small a heat change, will trigger it |
| TIME | On-time, Duration | how long the light stays on after the last detected motion |
| LUX | Dusk, Daylight, ☀/☾ | how dark it must be before the sensor is active |
The right order
1. Aim the head first
Dials can’t fix bad aim. Point the sensor so its coverage ends where your property does, tilted slightly down. PIR sensors detect movement across their field far better than movement straight toward them, so aim so that people cross the coverage, e.g. across a path rather than down it. See where to mount outdoor motion sensor lights.
2. Set TIME to its minimum (or TEST)
This gives you fast feedback while you adjust everything else. Many fixtures have a TEST position that also ignores daylight so you can set up during the day.
3. Set LUX to daylight (☀) for testing
So the sensor works while you walk-test in daylight. You’ll turn it back later.
4. Walk-test and adjust SENS
Start with sensitivity at about the middle. Walk across the edge of the area you want covered, then just outside it. Raise sensitivity until the light reliably triggers at the edge, and lower it if it triggers outside. Wait for the light to switch off between passes.
5. Set the final TIME
One to five minutes suits most paths and driveways. Longer times mean more on-time from every false trigger.
6. Set LUX for night
Turn the LUX dial to the dark end (☾) and let it run for an evening. If the light comes on too late at dusk, move it a little toward ☀.
Seasonal adjustment
PIR sensitivity depends on the temperature difference between a body and the background. On hot nights that difference is small, so range drops. In cold weather it is large, so range grows and false triggers increase. A small sensitivity tweak in summer and winter is normal.
If the dials don’t seem to work
- Wait for the light to fully switch off between tests; it ignores new settings until it resets on some models.
- Power-cycle at the breaker for about a minute.
- Check it isn’t in manual override mode: see motion sensor light stays on.