# Occupancy Sensor - Quick Reference SSO **Device Type:** Binary Input - Motion/Presence Detection **Signal:** Dry contact (relay output) or 0-10VDC **Power:** 24VAC/VDC or 120VAC (depending on model) **Version:** 1.0 | **Date:** Dec 2025 --- ## DEVICE OVERVIEW **Common Models:** - Leviton OSC/ODC, Lutron LOS, Wattstopper DT/CI, Honeywell HRME, Sensor Switch CMD **Used For:** Lighting control (auto on/off), HVAC setback (unoccupied mode), demand control ventilation, security/access, energy savings **Technologies:** - **PIR (Passive Infrared):** Detects body heat/motion - best for large open areas - **Ultrasonic:** Detects movement via sound waves - best for restrooms, behind obstructions - **Dual-Tech:** PIR + Ultrasonic combined - reduces false triggers - **Daylight Harvesting:** Integrated light sensor for dimming control **Specifications:** - **Detection Range:** * Ceiling mount PIR: 360° coverage, 20-30 ft radius * Wall mount PIR: 180° coverage, 15-20 ft range * Ultrasonic: 10-15 ft typical - **Output:** * Dry contact relay (NO or NC) * 0-10VDC analog (for dimming or occupancy level) - **Power:** 24VAC/VDC (low-voltage) or 120VAC (line-voltage) - **Time Delay:** Adjustable 30 sec - 30 min typical - **Sensitivity:** Adjustable (low/medium/high) **Environment:** Indoor, 32-104°F, 0-95% RH non-condensing --- ## SAFETY - PPE REQUIRED - ☑ Safety glasses (ANSI Z87.1) - ☑ Work gloves - ☑ **Insulated gloves if 120VAC model** - ☑ Ladder safety equipment (ceiling mount) ### HAZARDS - ⚠️ **LADDER WORK** - Most common hazard (ceiling mounting) - ⚠️ **LINE VOLTAGE** - 120VAC models have lethal voltage - ⚠️ **FALLING OBJECTS** - Sensor or tools can fall during ceiling install ### LOCKOUT/TAGOUT - [ ] **Required for 120VAC models** - Lock out lighting circuit - [ ] NOT required for 24VAC/VDC low-voltage models - [ ] Verify voltage before touching wires --- ## INSTALLATION CHECKLIST ### TOOLS NEEDED - Drill + bits - Wire strippers - Screwdrivers - Multimeter - Ladder (appropriate height) - Voltage tester - Label maker - Small flathead (for DIP switch adjustment) ### MATERIALS - Occupancy sensor (correct type for application) - Wire (18AWG for low-voltage, 14AWG for line-voltage) - Wire nuts - Ceiling/wall mounting hardware - Labels ### PRE-INSTALL - [ ] Select correct sensor type (PIR, ultrasonic, dual-tech) - [ ] Verify coverage area adequate for space - [ ] Confirm mounting height appropriate (8-12 ft typical for ceiling) - [ ] Check power available (24V or 120V) - [ ] Review wiring diagram for model ### INSTALL STEPS - CEILING MOUNT (Most Common) **STEP 1: Locate Mounting Position** 1. **Coverage considerations:** - Center of room preferred (360° PIR coverage) - Avoid corners (dead zones behind sensor) - Avoid direct line of sight to HVAC diffusers (air movement triggers ultrasonic) - Avoid windows with direct sunlight (can trigger PIR) - Height: 8-12 ft typical (follow manufacturer spec) 2. **Mounting location:** - Ceiling: Use electrical box or sensor mounting bracket - Wall: 6-8 ft height typical, aimed at expected occupant location **STEP 2: Install Sensor** **LOW-VOLTAGE (24VAC/VDC) - MOST COMMON FOR BAS:** 1. **Lock out power** if integrating with lighting circuit 2. **Mount sensor to ceiling:** - Attach to electrical box or bracket - Route low-voltage control wire through ceiling to sensor 3. **Connect wiring:** - **Power (if required):** * Red: +24VAC/VDC * Black: Common - **Relay Output to Controller:** * Relay NO: To controller binary input * Relay COM: To controller common - **When occupied:** Relay closes = BI TRUE - **When vacant:** Relay opens = BI FALSE 4. **Tighten terminals:** 7-9 in-lbs **LINE-VOLTAGE (120VAC) - LIGHTING CONTROL:** 1. **LOCK OUT lighting circuit breaker** 2. **Verify 0V with voltage tester** 3. **Mount sensor** 4. **Connect wiring:** - Black (hot) from breaker → Sensor line input - White (neutral) → Sensor neutral - Red (switched hot) → Sensor load output → Lighting - Green/bare (ground) → Sensor ground 5. **For BAS integration:** - Use sensor's low-voltage relay output (if available) - Connect relay to controller binary input **STEP 3: Configure Sensor Settings** **DIP SWITCHES or ROTARY DIALS (varies by model):** 1. **Time Delay:** - Lighting: 5-15 min typical - HVAC: 15-30 min typical - Set longer for areas with intermittent occupancy 2. **Sensitivity:** - High: Detects small movements (office, classroom) - Medium: Normal movements (conference room) - Low: Large movements only (warehouse) 3. **Mode:** - Auto On/Auto Off: Turns on when occupied, off when vacant - Manual On/Auto Off: Must manually turn on, auto turns off - Vacancy Mode: Manual on, auto off (energy code compliant in some areas) 4. **Photocell (if equipped):** - Enable: Prevents operation if daylight adequate - Disable: Operates regardless of light level 5. **Coverage Pattern (some models):** - 360° for ceiling mount - Sector coverage for wall mount **STEP 4: Label Wiring** - Example: "RM-201-OCC" (Room 201 Occupancy) - Label at both sensor and controller ends **STEP 5: Test and Adjust** - See Proof Out Tests section ### POST-INSTALL - [ ] Sensor mounted securely (ceiling or wall) - [ ] Coverage area verified - [ ] Wiring terminated tight - [ ] Settings configured (time delay, sensitivity, mode) - [ ] Labels applied - [ ] Work area cleaned - [ ] Photos taken --- ## EXPECTED READINGS ### INITIAL POWER-UP (Room Empty) - **After time delay expires:** Relay open = FALSE/0 (vacant) - **Sensor LED:** May blink when detecting motion (varies by model) ### OCCUPIED (Person in Room) - **Relay Output:** Closed = TRUE/1 (occupied) - **Controller Display:** Shows "Occupied" - **Sensor LED:** May illuminate or blink (varies) ### VACANT (Person Leaves Room) - **During time delay:** Relay stays closed (still occupied) - **After time delay:** Relay opens = FALSE/0 (vacant) - **Example:** 15-min delay means sensor shows vacant 15 min after last motion --- ## PROOF OUT TESTS ### TEST 1: Initial Detection Test - **Do:** Walk into sensor coverage area - **Expect:** * Sensor LED blinks or illuminates (if equipped) * Relay closes within 1-2 seconds * Controller shows "Occupied" - **Pass If:** Sensor detects occupancy immediately ### TEST 2: Coverage Area Test - **Do:** Walk around room in grid pattern, all areas - **Expect:** * Sensor detects motion in all areas * No "dead zones" where motion not detected - **Pass If:** Full room coverage confirmed - **If dead zones:** Adjust sensor aim or add additional sensor ### TEST 3: Time Delay Verification - **Do:** 1. Occupy room (trigger sensor) 2. Leave room and stand outside 3. Time how long until sensor shows vacant - **Expect:** Sensor shows vacant after configured time delay - **Pass If:** Time delay matches setting (±10%) - **Example:** Set to 15 min, should trigger 14-16 min after last motion ### TEST 4: Sensitivity Test - **Do:** Make small movements (typing, reading) in various locations - **Expect:** * High sensitivity: Detects small movements * Medium sensitivity: Detects normal movements * Low sensitivity: Detects only large movements - **Pass If:** Sensitivity appropriate for space use - **Adjust if:** False triggers (too sensitive) or misses occupancy (not sensitive enough) ### TEST 5: False Trigger Test - **Do:** Room empty, observe sensor for 30 minutes - **Expect:** No false triggers from: * HVAC airflow * Sunlight movement * Reflections * Nearby motion outside room - **Pass If:** No false occupancy triggers - **If false triggers:** Adjust sensitivity, reposition sensor, or cover windows ### TEST 6: Integration with BAS - [ ] Sensor appears in controller BI list - [ ] Occupied/vacant status displays correctly - [ ] Graphics show occupancy status - [ ] HVAC responds to occupancy (setback when vacant) - [ ] Lighting responds (if integrated) - [ ] No communication errors --- ## TROUBLESHOOTING ### SENSOR NEVER SHOWS OCCUPIED 1. **Check power:** Verify 24VAC or 120VAC present 2. **Test sensor:** Walk directly under sensor, wave arms - **If LED blinks but no relay:** Wiring issue - **If no LED blink:** Sensor failed or power issue 3. **Check wiring:** Verify relay output connected to controller BI 4. **Test relay:** Measure continuity across relay contacts when occupied - **If no continuity:** Sensor relay failed 5. **Check controller config:** BI configured as NO contact? ### SENSOR ALWAYS SHOWS OCCUPIED 1. **Check for false triggers:** - HVAC airflow directly at sensor (ultrasonic) - Sunlight through windows (PIR) - Reflective surfaces (mirrors, shiny floors) - Motion outside room (open doorway) 2. **Reduce sensitivity:** Adjust to medium or low 3. **Reposition sensor:** Away from triggers 4. **Check wiring:** Short circuit causing relay to stay closed? 5. **Check relay:** Relay contacts stuck closed - replace sensor ### SLOW TO DETECT OCCUPANCY 1. **PIR sensors require motion:** - Person must move to be detected - Sitting still may not trigger sensor - **Solution:** Use ultrasonic or dual-tech 2. **Check sensitivity:** May be set too low - Increase sensitivity setting 3. **Check dead zones:** Person may be in coverage gap - Reposition sensor or add additional sensor ### SENSOR DOESN'T STAY ON LONG ENOUGH 1. **Increase time delay:** - Lighting: Try 10-15 min - HVAC: Try 20-30 min 2. **Check sensor type:** - PIR requires movement to reset timer - Ultrasonic better for seated occupants 3. **Consider dual-tech:** Maintains occupancy better ### SENSOR STAYS ON TOO LONG 1. **Decrease time delay:** - Set to minimum acceptable for application 2. **Check for false triggers:** - May be constantly re-triggering from HVAC, sunlight, etc. ### FALSE OCCUPANCY TRIGGERS **PIR False Triggers:** - Sunlight movement through windows → Add blinds or reposition - Heat sources (space heaters, equipment) → Reposition sensor - Air movement from diffusers → Adjust sensitivity **Ultrasonic False Triggers:** - HVAC air turbulence → Reposition or reduce sensitivity - Fans or moving equipment → Reduce sensitivity - Sound/vibration → Isolate sensor from vibration source ### SENSOR MISSES OCCUPANCY (Not Detecting Present Person) 1. **Check coverage area:** Person in dead zone? 2. **Increase sensitivity:** May be set too low 3. **Check sensor type:** - PIR only detects movement (not presence) - Person sitting still won't trigger PIR - **Solution:** Use ultrasonic or dual-tech 4. **Check sensor aim:** Wall-mount sensors must aim at occupied area 5. **Check obstructions:** Furniture, partitions blocking view --- ## ESCALATION - COMPLETE BEFORE CALLING ### PRE-ESCALATION CHECKLIST - [ ] Verified power at sensor (24VAC or 120VAC) - [ ] Tested sensor by walking under it (LED response) - [ ] Measured relay output continuity (open vs closed) - [ ] Checked wiring connections tight - [ ] Verified coverage area (no dead zones) - [ ] Checked for false trigger sources (HVAC, sunlight) - [ ] Adjusted sensitivity and time delay settings - [ ] Documented sensor behavior over 30+ minutes - [ ] Taken photos of sensor location and settings ### PROVIDE THIS INFO - **Sensor:** [Mfg / Model / Type: PIR/Ultrasonic/Dual / Location] - **Power:** 24VAC/VDC or 120VAC - **Coverage Area:** _____ ft² (room size) - **Mounting Height:** _____ ft - **Sensor Behavior:** Never occupied / Always occupied / Intermittent / Slow - **LED Activity:** Blinks / Doesn't blink / Always on - **Relay Status:** Open / Closed / _____ ohms - **Time Delay Setting:** _____ minutes - **Sensitivity Setting:** High / Medium / Low - **False Trigger Sources:** HVAC / Sunlight / None identified - **Symptoms:** [Specific problem] - **Steps Taken:** [Troubleshooting completed] ### CONTACTS - **Field Specialist:** [Phone] - **Electrician:** [Phone] (if 120VAC wiring issue) - **Programmer:** [Phone] (if control logic issue) - **Dispatch:** [Phone] --- ## COMMON ISSUES & TIPS ✓ **Sensor selection:** PIR for large open areas, ultrasonic for restrooms/obstructed areas, dual-tech for best performance ✓ **Mounting height:** 8-12 ft typical - too high reduces sensitivity, too low reduces coverage ✓ **Time delay:** Longer for HVAC (20-30 min), shorter for lighting (5-15 min) ✓ **PIR limitation:** Only detects movement, not presence - person sitting still won't maintain occupancy ✓ **Ultrasonic advantage:** Detects small movements (typing, breathing) - better for seated occupants ✓ **False triggers:** HVAC airflow (ultrasonic), sunlight (PIR), nearby motion (both) ✓ **Dead zones:** Directly below ceiling mount sensor, behind obstructions ✓ **Energy codes:** Some jurisdictions require vacancy mode (manual on) vs auto on ✓ **Coverage overlap:** Multiple sensors can share same space, extend time delay ✓ **Dual-tech operation:** BOTH technologies must trigger for occupancy (reduces false triggers) ✓ **Daylight harvesting:** Use photocell to prevent operation during daylight (additional energy savings) ✓ **Integration:** Use for HVAC setback, lighting control, security, demand control ventilation ### Typical Applications & Time Delays - **Private Offices:** 15-20 min (intermittent occupancy) - **Conference Rooms:** 20-30 min (presentations = minimal movement) - **Classrooms:** 15-20 min (lecture = seated students) - **Restrooms:** 5-10 min (short-term occupancy) - **Break Rooms:** 10-15 min (variable use) - **Warehouses:** 30 min (large space, intermittent activity) - **Corridors:** 5-10 min (transient occupancy) --- **Document ID:** SSO-OCCUPANCY-001 **Revision:** 1.0 **Next Review:** Dec 2026