Here is a practical look at a widely used occupancy sensor — the Sensorworx SWX-201-2, a line-voltage PIR small-motion sensor designed for ceiling mounting. If you are selecting or installing an occupancy sensor for a commercial or residential lighting application, this guide covers what you need to know.
Specifications Overview
- Type — Passive Infrared (PIR), small-motion sensor, ceiling mount
- Physical — Approx. 4" diameter × 1.25" height; weight: 4.75 oz
- Operating Voltage — Multi-voltage (120–277 VAC)
- Load Rating — 800 W @ 120 VAC / 1200 W @ 277 VAC; suitable for tungsten, ballast, and LED loads
- Time Delay — Adjustable 30 seconds to 30 minutes (default 10 min)
- Detection Coverage — Up to recommended mounting height of 8–15 ft; sensor lenses swappable for coverage adjustments
- Code Compliance — Meets ASHRAE 90.1, IECC, Title 24 energy code requirements
Basic Wiring Diagram Overview
The SWX-201-2 is a line-voltage sensor, meaning it connects directly to the building's power supply — no separate low-voltage control wire is needed. The basic wiring is straightforward:
- Line (Hot) and Neutral supply feed the sensor.
- The sensor's load output connects to the lighting fixture.
- In multi-sensor setups wired in parallel, all sensors must time out to turn the lights off.
- Optionally, an override switch can be placed between the sensor and load for manual control.
What To Do Next
- Select the style (ceiling vs. wall switch) that suits your application.
- Ensure wiring compatibility — check whether your installation includes neutral wires.
- Follow manufacturer wiring diagrams precisely.
- Consider installation requirements — junction box space, voltage, load type, manual override needs, and applicable electrical codes.
Sample Devices for Comparison
1. SensorWorx SWX-222-1 Ceiling-Mount Occupancy Sensor
- Type: Dual-technology PIR/Acoustic, line voltage (120–277 VAC)
- Features: Occupancy detection, optional daylight harvesting (0-10 V dimming), auxiliary relay output for BMS interface
2. Leviton ODC Series (Ceiling-Mount Multi-Tech Sensor)
- Type: Multi-Technology (PIR + Ultrasonic)
- Voltage: 120 V up to 8 A (800 W); 230 V up to 6 A; 277 V up to 5 A (1200 VA)
3. Lutron Maestro MS-OPS6M2N-DV Occupancy/Vacancy Switch
- Type: Wall-mounted sensor switch, 120–277 VAC, single-pole and multi-location options
💡 Always conform to local electrical codes and recommendations — fail-safe wiring, types of loads, neutral requirements, and applicable energy code certifications.
Key Takeaways
- Select a device that suits your space (ceiling vs. wall, with or without daylight control).
- Ensure wiring compatibility — ceiling units need neutral and load access in the box.
- Follow manufacturer wiring diagrams precisely for your voltage configuration.
- Compliance: Always conform to local electrical codes and recommendations.
