Commercial Lighting Control Systems: Sensors, DALI, 0–10 V and Wireless
How commercial lighting controls work: occupancy and daylight sensors, schedules, 0–10 V and DALI, wireless systems, typical savings, and choosing controls by building type.
Key points
- Controls add 20–60% savings on top of an LED upgrade, depending on how much of the time spaces are empty or daylit.
- The main strategies are occupancy sensing, daylight harvesting, scheduling and task tuning.
- 0–10 V is simple analogue dimming; DALI is digital and addressable; wireless systems avoid control cabling in retrofits.
- Choose controls for how the building is used: warehouses gain most from occupancy, offices from daylight and schedules, car parks from both.
LED made lighting efficient; controls make it smart. A light that is off or dimmed when nobody needs it uses no energy at all, and LED, unlike older lamps, can dim and switch instantly without harm. That makes controls the next step after any LED upgrade.
Control strategies
| Strategy | How it works | Typical saving | Best for |
|---|---|---|---|
| Occupancy / vacancy | Lights on or up when people are present | 20–60% | Warehouses, toilets, meeting rooms, car parks |
| Daylight harvesting | Dims lights near windows and skylights | 20–40% in daylit zones | Offices, schools, warehouses with skylights |
| Scheduling | Time-based on, off and dim levels | 10–30% | Whole buildings, outdoor lighting |
| Task tuning | Sets maximum output to what is needed | 10–20% | New over-lit installations |
| Personal control | Users dim their own area | Comfort; small savings | Offices |
Savings overlap, so they do not simply add up, but combined they often reach 40–60% in suitable buildings.
Sensors
| Sensor | Detects | Notes |
|---|---|---|
| PIR | Body heat moving | Needs line of sight; good for offices and toilets |
| Microwave | Any movement | Works through covers; good for high bays and car parks |
| Dual-technology | PIR + ultrasonic or microwave | Fewer false offs in offices |
| Daylight (photosensor) | Light level | For daylight dimming |
In warehouses, microwave sensors integrated in high bays detect forklifts and people in aisles. In offices, ceiling PIR or dual-tech sensors cover desks and meeting rooms.
Dimming interfaces
| Interface | How | Pros | Cons |
|---|---|---|---|
| 0–10 V (1–10 V) | Analogue voltage on two wires | Simple, common, low cost | Group control only, extra wires, voltage drop on long runs |
| DALI / DALI-2 | Digital bus, 64 addresses per line | Individual control, feedback, scenes | Commissioning effort, cost |
| Phase-cut (TRIAC) | Dims the mains waveform | Uses existing wiring | Mostly residential; compatibility issues |
| Wireless (Zigbee, Bluetooth mesh, proprietary) | Radio in each fixture or sensor | No control wiring, easy retrofit | Network planning, security |
| PoE lighting | Power and data over network cable | Integration with IT | Niche, higher cost |
Networked and standalone systems
- Standalone: sensors in each fixture or room, no central system. Simple and cheap; settings are local.
- Networked: sensors, fixtures and switches on a network with software. Allows scheduling, energy reports, fault alerts and changes from a central screen.
For large buildings and campuses, networked systems make maintenance easier and verify savings.
By building type
| Building | Recommended controls |
|---|---|
| Warehouse | Occupancy per aisle (microwave), daylight near skylights, schedules |
| Factory | Zones per process area, schedules, daylight |
| Office | Daylight dimming near windows, occupancy in meeting rooms and toilets, schedules |
| School | Daylight, occupancy in classrooms, schedules |
| Car park | Occupancy with low background level, daylight for open decks |
| Retail | Schedules, scenes for opening and cleaning |
| Outdoor | Photocell or astronomical timer, dimming after midnight |
For car parks, see parking garage lighting; for offices, office light fixtures.
Warehouse example
A warehouse with 150 LED high bays of 150 W, lit 6,000 hours a year:
- Without controls: 150 × 150 W × 6,000 h = 135,000 kWh
- With aisle occupancy sensors dimming to 20% when empty, average about 50% power: about 67,500 kWh
At US$0.12/kWh, controls save about US$8,100 a year on top of the LED upgrade. Our UFO high bays can be supplied with dimmable drivers and sensors.
Commissioning
Controls only save energy if set correctly:
- Set time delays (often 5–15 minutes for offices, 2–5 minutes for warehouse aisles)
- Set background dim levels (10–30%)
- Calibrate daylight sensors on a bright day
- Check sensor coverage, especially in racked aisles
- Train facility staff to adjust settings
Poor commissioning is the most common reason controls disappoint.
Codes and standards
Many energy codes now require automatic shut-off, occupancy controls in certain rooms and daylight controls in daylit zones. Check local requirements before designing; controls may be mandatory, not optional.
Retrofitting controls
- Wireless sensors and nodes add control without new wires
- Integrated sensors in new LED fixtures add control at little extra cost
- Smart relays on existing circuits give schedule control
Common mistakes
- Sensors with too short delays, annoying users
- Daylight sensors left uncalibrated
- Mixing dimming types on one circuit
- No one responsible for settings after handover
Energy reporting
Networked systems can report energy per zone or fixture. This helps to verify savings, find areas where lights stay on unnecessarily and support energy certificates. Even simple systems with a sub-meter on the lighting circuit show whether controls are working: a sudden rise in lighting energy often means a sensor or schedule has been overridden.
Security and IT
Networked lighting connects to building networks. Use systems with encryption, change default passwords, keep firmware updated and agree with the IT team how the lighting network is separated from other systems. Wireless systems should be planned so that every fixture has a reliable link.
Future-proofing
Even if a project starts without controls, choose dimmable drivers and fixtures with sensor-ready sockets or integrated sensor options. Adding controls later is then a configuration task rather than a re-wiring job.
Who should own the settings
Name one person or team responsible for lighting settings after handover. Without an owner, schedules drift, sensors get taped over and savings disappear within a year. A short settings sheet per area, kept with the building manual, makes changes easy to track.
Ordering
Send the building plan, how areas are used and any control preference (0–10 V, DALI, wireless). We will propose fixtures with matching drivers and sensors.
Sources
Frequently asked questions
What is a lighting control system?
A set of sensors, switches, drivers and software that decide when lights are on and how bright they are, based on occupancy, daylight, time and user settings. It reduces energy and can improve comfort.
What is the difference between 0–10 V and DALI?
0–10 V is an analogue signal on two control wires; all drivers on the circuit dim together. DALI is a digital bus where each driver has an address, so lights can be controlled individually or in groups and can report status.
How much do lighting controls save?
Typically 20–40% in offices with daylight and occupancy controls, and 40–70% in warehouses and car parks where spaces are often empty, on top of the savings from LED.