Complete Wiring Guide for Lutron Maestro MS-OPS2 Occupancy Sensor Switch

Begin by connecting the neutral wire to both switch terminals marked with N–this ensures stable power delivery across all loads. The hot feed (line) must attach to the L or common terminal of the primary switch, while the second terminal should link to the first load (e.g., overhead lighting). For the auxiliary switch, connect the second hot wire to its L terminal, then run the other load (such as a ceiling fan or secondary fixture) from its remaining terminal.

For occupancy sensing functionality, confirm the ground wire is secured to the dedicated G terminal. If integrating with dimmable fixtures, verify compatibility with LED or incandescent bulbs–most models handle up to 300W resistive or 150W dimmable LED loads. Mismatched wattage risks flickering or sensor failure.

Test the setup by toggling both switches manually before relying on motion detection. If the sensor fails to engage, check for loose connections or reverse polarity between the line and load wires. Adjust the sensitivity dial (typically located on the side) to balance between false triggers and reliable operation–start at medium and fine-tune as needed. Avoid placing the unit near HVAC vents, direct sunlight, or reflective surfaces to prevent erratic activation.

For three-way applications, replace the existing mechanical switch at the far end with a momentary push-button or compatible remote switch. Wire the remote’s common terminal to the sensor’s 3-way terminal, then connect the traveler wires between the two locations. Ensure the remote is rated for the same voltage (120V or 277V) to avoid damage.

Installation Guide for Dual-Sensor Occupancy Switch

Strip 1/2 inch of insulation from the neutral wire at the circuit breaker and connect it to the terminal labeled “N” using a twist-on wire connector. The device requires a neutral connection for proper operation–verify its presence in the junction box before proceeding. If absent, consult a licensed electrician to modify the wiring configuration; alternatives like ground-mounted setups void UL certification.

For single-pole applications, attach the load wire to the brass screw marked “LOAD” and the line wire to the adjacent “LINE” terminal. Ensure secure tightening of screws–loose connections cause intermittent sensor failures. In multi-way setups, wire the companion switch first, then follow the same polarity for the master unit. Reverse polarity triggers false occupancy detection, disabling automatic shutoff functionality.

Adjusting Sensitivity and Time Settings

After power restoration, press and hold the small button on the side for five seconds until the LED flashes twice. This enters programming mode. Use the rocker switch to reduce motion sensitivity in cluttered spaces–each press cycles through levels 1 (low) to 3 (high). Factory default (level 2) suits most residential areas; level 1 prevents detection of pets under 40 lbs.

To modify the timeout duration, press the same button once during the initial flash sequence. Each tap increments the delay: 1 minute (single flash), 5 minutes (two flashes), 15 minutes (three flashes), and 30 minutes (steady illumination). The default 15-minute setting balances energy savings and convenience. Reset to factory defaults by holding the button for ten seconds until a continuous red glow appears.

Test all configurations with minimal ambient light–fluorescent or LED bulbs below 3W may interfere with passive infrared readings. For day/night differentiation, wire the red “AUX” lead to a compatible photocell; omit this step if automatic lighting control isn’t required. Document final settings using the included label sticker to simplify future troubleshooting.

Identifying Terminal Connections on the MS-OPS2 Occupancy Sensor

Locate the backplate of the device–four terminal screws are arranged in a horizontal row, labeled left to right as Ground (GND), Neutral (N), Load (L), and Line (L). Verify labels with a non-contact voltage tester before touching any screw.

The Ground (GND) screw is always green and accepts either a bare copper wire or a green-insulated conductor. Secure it with at least three clockwise wraps around the screw shank to ensure a low-resistance path.

The Neutral (N) terminal sits immediately to the right of ground. It must connect to the white wire from the supply circuit. Strip 5/8 inch of insulation, form a hook, and clamp it under the screw head; torque to 12 in-lbs to prevent overheating.

• Line (L) input is the screw farthest right. Attach the black or red hot wire from the breaker panel here–never connect both line and load wires to the same terminal.
• Load (L) screw is one position left of line. Feed the black wire leading to the controlled fixture into this slot. Mixing line and load will trip the breaker instantly.

Check continuity between neutral and ground with a multimeter set to 200 Ω; readings above 0.5 Ω indicate loose crimps or corroded conductors–clean contacts with fine sandpaper if necessary.

Color Coding Pitfalls

European installations often use brown for line and blue for neutral; North American projects reverse white and black roles. Always cross-reference local codes–miswiring brown to neutral trips AFCI breakers within seconds.

1. Disconnect power at the breaker.
2. Label every wire with tape showing origin (breaker, fixture, etc.).
3. Twist stripped ends with pliers before inserting into terminals; strands can stray and cause short circuits.
4. Apply silicone dielectric grease to terminals exposed to outdoor humidity.
5. Restore power and verify sensor operation with a 30-second test cycle.

After securing connections, fold wires neatly into the electrical box–excess slack pushes against the sensor lens, triggering false positives during temperature swings.

Single-Pole Connection Guide for Two-Wire Switch Setups

Verify power is off at the circuit breaker before handling any conductors. Use a non-contact voltage tester to confirm no live current remains in the box. If replacing an existing mechanism, document the original setup with photographs to simplify reattachment of cables.

Identify the incoming power line (typically black or red) and the feed to the fixture (often another black or red wire). In standard residential setups, the neutral (white) and ground (bare copper or green) are shared between source and load. These must be connected directly–never route them through the control device.

Strip approximately 3/8 inch of insulation from each conductor using wire strippers. Twist the exposed strands tightly to prevent fraying. Insert the live input wire into the brass screw terminal marked “common” or “line,” ensuring no bare copper extends beyond the clamp. Tighten securely.

Attach the output conductor to the remaining brass terminal, labeled “load” or identified by a distinct color on the device’s faceplate. Again, confirm no stray strands protrude after fastening. Mismatching these connections will prevent proper operation and may risk overheating.

• For metallic junction boxes: Connect the ground wire to the box’s grounding screw or directly to the mechanism’s green screw.
• For plastic or non-conductive enclosures: Bond all grounding conductors together with a twist-on connector, including a pigtail to the device if required.
• If the fixture lacks a ground connection, cap the bare wire with a wire nut and tuck it aside safely.

Fold the connected conductors neatly into the junction box, pushing excess slack toward the rear. Secure the control unit to the box with mounting screws, ensuring it sits flush against the wall. Align the faceplate perpendicular to the floor for consistent illumination response.

Testing and Troubleshooting

Restore power at the breaker. Press the upper portion of the switch face to activate; the lower half should deactivate. If unresponsive or behaving erratically:

1. Recheck all connections for loose strands or incorrect terminal placement.
2. Verify the breaker is on and that the fixture itself hasn’t tripped or failed independently.
3. Test with a multimeter: between the “line” terminal and ground should read ~120V when off and 0V when on.
4. Ensure the neutral wires are properly bonded–open neutrals cause flickering or intermittent operation.

For dual-circuit installations requiring separate controls, follow this procedure for each switch, isolating their respective loads with care to prevent cross-wiring. Never combine feeds from different breakers on a single device unless explicitly designed for multi-pole use.

Setting Up Two-Location Control with Neutral and Non-Neutral Connections

Connect the load wire to the gold screw terminal at the primary switch location, ensuring the brass traveler screw pairs are linked to the same colored conductors from the auxiliary unit. For neutral-equipped circuits, attach the white return wire to the silver neutral terminal–confirm continuity by testing voltage between this point and the grounded conductor before securing connections with wire nuts rated for 600V. Non-neutral configurations require bypassing the silver terminal; instead, splice the return path directly into the traveler pair using a pigtailed junction where the dimmer’s internal circuit grounds through the load.

Troubleshooting Mismatched Voltage Readings

Measure across traveler terminals with a multimeter set to AC voltage: expect 120V between either traveler and neutral in standard setups, or line-to-load readings if neutral is absent. If voltages deviate (±5V), recheck terminal tightness–loose screws cause intermittent contact. For flickering loads, swap the connected travelers at one switch; improper polarity manifests as erratic illumination levels. Use stranded 14 AWG copper core for flexible links between devices, stripping exactly 5/16″ of insulation to prevent shorting under terminal plates.