High Bay Sensors: Motion & Daylight Controls | Hyperlite

Combining Motion and Daylight High Bay Sensors: Practical Guide for UFO Fixtures

For commercial and industrial spaces, the biggest energy savings from LED high bays often come after the fixtures are installed. The real step change happens when you combine motion (occupancy/vacancy) and daylight sensors on a solid 0–10 V dimming backbone.

In this guide, I’ll walk through how to design, wire, and commission a dual‑sensor strategy for UFO high bay lights so that they are only on when needed, and only as bright as necessary. The focus is practical: what to specify, how to avoid control conflicts, and how to pass code and rebate reviews without callbacks.

1. Why Combine Motion and Daylight Sensors on High Bays?

1.1 Code compliance and rebate leverage

Most new commercial and many retrofit projects now require automatic controls. Standards such as ASHRAE 90.1‑2022 and the 2024 International Energy Conservation Code (IECC) mandate occupancy sensing and often some form of daylight‑responsive control in many spaces.

Both documents limit lighting power density (LPD) and require automatic shutoff and multi‑level control. In practice, that means:

Lights must switch off or reduce output automatically when areas are vacant.
Daylit zones must dim or shut off when enough natural light is available.

If your high bay fixtures are on a 0–10 V dimming platform and are sensor‑ready, it becomes much easier to meet these requirements and document compliance. That, in turn, determines whether you qualify for many utility rebates that depend on standards like the DesignLights Consortium (DLC) QPL.

1.2 Energy savings beyond LED efficacy

DOE’s FEMP guidance on energy‑efficient luminaires sets minimum lumens‑per‑watt targets for commercial and industrial LED luminaires, but it also stresses that controls are required to capture the full savings. In field projects I’ve seen:

LED high bays alone typically cut energy use by 50–65 % versus metal halide or high‑pressure sodium.
Adding well‑tuned occupancy and daylight controls usually adds another 20–40 % reduction in lighting kWh, depending on schedule and glazing.

That additional 20–40 % is exactly what shortens payback and often makes DLC‑listed high bays eligible for the highest rebate tiers, as shown in many utility tables aggregated through tools like the DSIRE incentive database.

1.3 Comfort, safety, and visual performance

For warehouses, production floors, or garages, controls are not just about energy:

No dark aisles: High bays can dim down instead of switching fully off, keeping wayfinding and safety intact.
Better visual adaptation: Step‑dimming and daylight tracking avoid sudden jumps from dark to bright, which is helpful where forklifts and pedestrians share circulation paths.
Code‑friendly multi‑level lighting: You can deliver high illuminance when needed for tasks, then drop to lower levels that still meet guidance such as ANSI/IES RP‑7 for industrial facilities when the space is lightly used.

2. Controls Architecture: How Motion and Daylight Work Together

2.1 Basic 0–10 V dimming topology

Most UFO high bay drivers use 0–10 V dimming with two low‑voltage control leads in addition to the line (hot), neutral, and ground conductors.

10 V ≈ 100 % output.
0–1 V ≈ minimum dim level (often 10 – 20 % of full output, or off, depending on driver settings).

Sensors either send a control voltage on this pair (0–10 V) or sink current from an internal 10 V source in the driver. Before you select controls, confirm from the driver datasheet whether it expects a current‑sinking or current‑sourcing device. This is a critical step; mismatches are one of the most common causes of “sensor wired but dimming doesn’t work” callbacks.

2.2 Motion (occupancy/vacancy) sensors

For high bay applications you typically see:

Ceiling‑mounted occupancy sensors rated for 20–40 ft mounting heights.
Aisle‑mounted sensors aimed along racking aisles to avoid blocking from pallets.

The DOE guide on wireless occupancy sensors highlights practical limits on detection at high ceilings and warns about obstructions—exactly the issues we see in warehouses.

Field‑tested coverage rules of thumb:

20–25 ft ceilings (open floor): plan for about 1 sensor per 1,500–3,000 ft².
30–40 ft ceilings: coverage per sensor can increase to 3,000–6,000 ft², but only in unobstructed bays; racking and machinery reduce effective range.

For racked aisles, experience shows that aisle‑mounted or staggered sensors outperform single ceiling‑centered sensors. Pallets and racking frequently block line of sight, so mounting sensors near the aisle midline, aimed along the aisle, improves pickup and prevents lights from dropping out while staff are in the aisle.

2.3 Daylight sensors (photosensors)

Daylight sensors (photocells or photosensors) measure available natural light and adjust the 0–10 V signal to keep task illuminance near a target setpoint.

Typical implementation in high bay spaces:

A sensor monitors light from skylights or high windows in a defined zone.
The sensor sends a 0–10 V signal to a group of fixtures in that daylit zone.
As daylight increases, the control voltage is reduced and the luminaires dim.

Most warehouse and factory projects use open‑loop or closed‑loop dimming:

Open‑loop: sensor sees only daylight (mounted to look away from luminaires). Best for skylight rows.
Closed‑loop: sensor sees combined daylight + electric light and dims until total illuminance matches setpoint.

According to the California Title 24, Part 6 lighting controls guide, primary daylit zones must provide either continuous or multi‑level dimming and turn lights off when daylight alone meets the design target. Combining a 0–10 V daylight sensor with dimmable high bays is the straightforward way to satisfy this.

2.4 Who’s in charge: priority between motion and daylight

When you combine both sensor types, you must decide which signal has priority. A reliable hierarchy is:

Occupancy controls ON/OFF (or high/low). If the area is vacant, the lights should be at a low trim level or off regardless of daylight.
Daylight controls trim the occupied level. When the space is occupied, daylight sensors adjust the dim level between a programmed minimum (for safety) and full output.

In practice, this means:

Occupancy sensor controls relay or high‑level enable for the driver or control module.
Daylight sensor adjusts the 0–10 V level while the relay is engaged.

This prevents situations where a daylight sensor tries to dim a light that an occupancy sensor has already turned off, which can otherwise lead to flicker or odd ramp‑up behavior.

3. Wiring Strategies for Dual‑Sensor High Bay Control

Safety note: Always follow the National Electrical Code (NFPA 70), local codes, and manufacturer instructions. When in doubt, coordinate with the engineer of record and the authority having jurisdiction (AHJ).

3.1 Common myth: “Just parallel any 0–10 V sensors and it will work.”

A frequent misconception on job sites is that you can simply tie multiple 0–10 V devices in parallel on the same control pair and they will “average out.” In reality, many drivers and sensors are current‑sinking devices. When you parallel them without design, you get:

Conflicting voltage outputs
Grounding loops
Unstable or non‑functional dimming

A better approach is to use either:

A single multi‑function sensor that handles motion and daylight in one device; or
A coordinated topology where one device has priority and the other feeds an input on a control module designed for multiple controls.

Do not parallel multiple passive sensors on one 0–10 V lead unless the control manufacturer explicitly allows it.

3.2 High‑level architecture options

Here are three practical architectures for combining motion and daylight sensors on UFO high bays.

Architecture	Wiring Complexity	Flexibility	Typical Use Case
A. Integrated “2‑in‑1” sensor per fixture	Low	Medium	Small spaces, retrofits, garages, low channel count
B. Remote sensor per zone (line‑voltage relay + 0–10 V control)	Medium	High	Warehouses with daylit/non‑daylit zones, multiple rows
C. Centralized control module with multiple sensor inputs	High	Very high	Large facilities, advanced scheduling, BMS integration

Architecture A: Integrated sensor per fixture

Each UFO high bay has a plug‑in or twist‑on sensor head that includes both occupancy and daylight functions.
The sensor typically switches line voltage (or low‑voltage enable) and sends a 0–10 V dimming signal according to both motion and light level.

Pros:

Simple to install and explain to crews.
Fixture manufacturer has already resolved priority between motion and daylight.
Ideal for one‑to‑one replacement projects where zoning can be simple.

Cons:

Less flexible for row‑based zoning in long aisles.
Adjusting trim levels fixture‑by‑fixture can be tedious without a commissioning tool.

Architecture B: Remote sensor with zone control

Occupancy sensors (often aisle‑mounted) control a relay feeding a row or zone of high bays.
A daylight sensor feeds a 0–10 V signal to the same zone.

Wiring logic:

Line (hot): Panel → occupancy sensor (if switching line) → relay load out → fixtures.
Neutral/ground: Panel → fixtures (and sensors, as required).
0–10 V pair: Daylight sensor 0–10 V output → daisy‑chain to fixture dimming leads.

This design:

Lets you group fixtures serving the same daylit zone under one photosensor.
Keeps occupancy sensing aligned with the physical use pattern of the aisle or bay.

Architecture C: Centralized control module

A dedicated control module or networked lighting controller sits in a junction box or panel.
Multiple occupancy and daylight sensors feed the controller using low‑voltage inputs.
The module outputs several 0–10 V channels and relay outputs to different fixture groups.

This architecture suits projects that need:

Granular scheduling
Integration with building management systems
Trend logging for measurement & verification (M&V)

It also simplifies documenting compliance with IECC or ASHRAE 90.1 because you can export or screenshot control settings.

3.3 0–10 V wiring best practices

To keep commissioning smooth:

Separate line and control conductors. Treat 0–10 V runs as Class 1 or Class 2 consistent with driver and code requirements; consult NEC articles on Class 1 vs. Class 2 circuits when running in the same raceway.
Maintain polarity. Many drivers require “+” and “–” orientation on dimming leads.
Use proper cable type. In open warehouses, plenum‑rated or appropriately rated low‑voltage cable tied to structure is standard. Avoid loose zip cord.
Label everything. Label sensor feeds, 0–10 V home runs, and junction boxes. This pays off immediately during troubleshooting and for future rebate inspections.

For more detail on laying out the high bays themselves (spacing, aiming, beam angles), see the companion guides on warehouse lumens selection and beam angle vs. ceiling height.

4. Sensor Layout and Setpoint Tuning

Designing a dual‑sensor system is as much about placement and programming as it is about wiring.

4.1 Occupancy/vacancy sensor placement

Use the DOE wireless occupancy sensor applications guide as a reference for coverage diagrams, and apply these field‑proven practices:

Open floor warehouses (20–25 ft): start with 1 sensor per 1,500–3,000 ft² and verify coverage in lift and pedestrian paths.
High‑rack aisles: mount sensors either at the end of each aisle or mid‑aisle at 20–30 ft, with the detection pattern aligned along the aisle.
Work bays and QC zones: consider lower mounting heights or additional sensors because workers are often stationary.

Recommended vacancy timeouts based on experience:

Aisles and transient zones: 30–60 s. This keeps lights from burning for long periods after a forklift passes but avoids nuisance off during brief pauses.
General open areas: 5–15 min depending on activity and safety policy.

These are practical starting points; always cross‑check against local code minimums and owner preferences.

4.2 Daylight zoning and sensor aiming

First, identify primary daylit zones (typically within one mounting height of skylights or large vertical windows). Title 24 and IECC both define how far these zones extend from glazing; using those definitions keeps you aligned with plan reviewers.

Then:

Group fixtures into daylit and non‑daylit zones. High bays in interior bays without skylight exposure often don’t need daylight sensing, only occupancy.
Mount the photosensor where it sees representative daylight, not under the darkest or brightest spot.
Aim away from fixture glare. For closed‑loop sensors, follow manufacturer guidance to avoid direct view of the LED source, which can confuse readings.

A practical daylight setpoint for many warehouses is to have the sensor maintain about 20–50 lux from the electric lighting component when daylight is present, so total target illuminance (daylight + electric) stays near the design value from standards like ANSI/IES RP‑7.

4.3 Commissioning workflow that actually works in the field

Commissioning is often rushed. These steps keep you out of trouble:

Verify control topology. Before powering up, confirm that drivers and sensors are paired correctly as current‑sinking or sourcing, and that 0–10 V polarity is correct.
Load the space. Do not commission in an empty warehouse if the final condition includes tall racks and full pallets. Obstructions change occupancy sensor performance and daylight distribution.
Disable demo/test modes. Many sensors ship in test mode (very short timeouts). Always change to normal operation before turnover.
Program occupancy first. Set occupancy behavior (ON level, partial‑OFF level, vacancy timeout). Test walk‑throughs and forklift movements.
Then program daylight dimming. With occupancy behavior locked, adjust daylight setpoints during a period with adequate natural light.
Check emergency egress circuits. Emergency or standby luminaires must remain on regardless of sensor state. Verify that emergency circuits are not inadvertently controlled by occupancy devices, in line with guidance in NEMA lighting systems standards and local codes.
Document and label. Record sensor locations, channels, and setpoints in as‑built drawings. This helps owners meet measurement and verification expectations under programs cataloged in DSIRE and simplifies future adjustments.

5. Real‑World Scenarios: How Dual Sensors Pay Off

5.1 Medium warehouse retrofit with skylights (20 ft ceiling)

Existing condition

100 metal halide high bays at 400 W each.
No controls beyond manual switches.

Upgrade

100 LED UFO high bays at ~150–200 W each, 0–10 V dimming, IP65, sensor‑ready.
Open floor with sawtooth skylights over two central rows.

Controls design

Occupancy: 1 ceiling‑mounted sensor per ~2,000 ft², 30 s timeout in aisles, 10 min in open bays.
Daylight: 2 photosensors, each controlling one skylit zone of 25 fixtures via 0–10 V.

Performance
Analysis based on DOE solid‑state lighting case studies shows:

LED conversion alone: ~60 % energy reduction.
Occupancy + daylight controls: additional ~30 % reduction in lighting energy in daylit areas, ~20 % in non‑daylit areas.

Overall, the combined measures typically yield 70–75 % total kWh savings, with simple paybacks of 2–4 years once utility rebates (which often require DLC‑listed products and controls) are applied.

5.2 High‑rack distribution center (32 ft ceiling)

Existing condition

60 LED high bays already installed, basic on/off control.
32 ft mounting height, racking up to 28 ft, limited skylights.

Control objective

Add occupancy sensing without re‑running line voltage.

Solution

Wireless aisle‑mounted occupancy sensors tied to low‑voltage control modules.
Each module controls a row of 6–8 high bays via a 0–10 V channel.

Key lesson from this type of project, echoed in DOE’s wireless sensors guide: if you underestimate occlusion from pallet loads and rely on ceiling‑centered sensors, you will see false vacancy in aisles. Aisle‑mounted sensors aligned with forklift paths dramatically improve performance.

5.3 Owner concerns: “Will my lights flicker when both sensors act?”

If motion and daylight controls are mis‑coordinated, you can see:

Lights “hunting” around a dim level as people move and shadows change.
Short flashes when the occupancy sensor switches while the daylight sensor is dimming.

This is why a clear priority scheme and a clean 0–10 V architecture are critical. Use occupancy to decide whether the lights are on and at what broad level (e.g., 20 % vs 100 %), and allow daylight to fine‑tune within that band. Modern drivers following NEMA’s guidance on dimming behavior and flicker, together with proper programming, keep transitions smooth.

6. Installation & Commissioning Checklist

Use this checklist on site with your crew or commissioning agent.

6.1 Pre‑install

[ ] Confirm high bay drivers support 0–10 V dimming and identify sinking vs sourcing behavior.
[ ] Verify sensor device ratings for mounting height, environment (IP rating per IEC 60529), and temperature.
[ ] Decide on architecture (integrated sensors, zone‑based, or centralized module).
[ ] Define control zones to match code‑required spaces (daylit vs non‑daylit, open vs aisle).
[ ] Coordinate with engineer/AHJ regarding NEC Class 1/Class 2 wiring separation for 0–10 V runs.

6.2 Rough‑in and wiring

[ ] Install high bays according to layout and structural guidelines (see warehouse layout and safety guide for reference).
[ ] Run line voltage circuits with adequate spare capacity and dedicated neutrals where required.
[ ] Pull 0–10 V control wiring with correct cable type and color coding; maintain polarity.
[ ] Mount occupancy sensors and daylight sensors per manufacturer coverage diagrams.
[ ] Label junction boxes, sensor locations, and control home runs.

6.3 Functional testing

[ ] Verify each sensor powers up and, in test mode, can drive fixtures from min to max via 0–10 V.
[ ] Test all occupancy zones with actual traffic patterns (forklifts, pedestrians, stationary workers).
[ ] Confirm vacancy timeouts match owner expectations and code minima.
[ ] Validate daylight response on a bright day; adjust setpoints so lights dim smoothly without turning off prematurely.
[ ] Check emergency circuits are not controlled by occupancy/daylight sensors except as allowed by code.

6.4 Documentation

[ ] Record all sensor models, locations, channels, and setpoints in as‑built drawings.
[ ] Provide a one‑page control narrative summarizing sequence of operations (required by many IECC/ASHRAE‑based jurisdictions).
[ ] Capture photos or screenshots of sensor settings for rebate documentation to support applications based on DLC QPL and local utility forms.

7. Key Takeaways for Contractors and Facility Teams

Plan controls with the fixtures, not after. Choose UFO high bays with 0–10 V dimming and sensor‑ready options so you can layer motion and daylight controls without last‑minute redesign.
Give occupancy priority; let daylight trim. Use sensors or control modules that clearly separate ON/OFF (or high/low) logic from dimming logic.
Respect sensor physics. At 20–25 ft, plan roughly 1 occupancy sensor per 1,500–3,000 ft²; at 30–40 ft, assume 3,000–6,000 ft² only in open bays. Account for racks and machinery.
Use codes and standards as design guides, not just hurdles. IECC, ASHRAE 90.1, ANSI/IES RP‑7, and IEC 60529 give clear targets for illuminance, control behavior, and environmental protection.
Commission under real conditions. Sensors tuned in an empty shell building almost always need rework once racks, machinery, and product loads arrive.

For deeper dives, pair this guide with the layout‑focused article on designing high bay layouts for warehouse safety and the controls‑focused guide to Title 24 high bay lighting controls.

FAQ: Motion and Daylight Sensors on UFO High Bays

Q1. Can I add motion and daylight sensors later to existing high bays?
Yes, if the drivers support 0–10 V or a similar dimming protocol and there is a way to switch line voltage or low‑voltage enable. For older “on/off‑only” drivers, retrofitting usually means replacing the driver or the entire fixture.

Q2. Should every high bay have its own sensor?
Not necessarily. In large warehouses it is more efficient to zone fixtures—by aisle, bay, or daylit area—and control groups with shared sensors. Individual fixture sensors are convenient in small shops, garages, or when wiring access is limited.

Q3. What timeout should I program on occupancy sensors?
For aisles and circulation zones, 30–60 s is a proven range that balances savings and user comfort. For open areas or production spaces, 5–15 min is common. Always confirm local code minimums and adjust based on safety and operational feedback.

Q4. How do dual sensors help with code compliance?
Occupancy sensors provide the automatic shutoff and partial‑off functionality required by ASHRAE 90.1 and IECC. Daylight sensors provide multi‑level control and automatic daylighting in primary daylit zones, which those same codes treat as mandatory or prescriptive in many space types.

Q5. Will the lights wear out faster if they constantly dim and brighten?
Quality LED drivers and luminaires are tested under standards such as IES LM‑80 for lumen maintenance and are designed to handle frequent dimming. In practice, running at reduced output lowers thermal stress on the LEDs and drivers, which supports long life rather than shortening it—provided you use reputable, compliant equipment and follow installation guidance.

Disclaimer: This article is for informational purposes only and does not constitute professional engineering, electrical, or legal advice. Always consult the luminaire and controls manufacturers’ documentation, the project’s design engineer, and applicable codes and standards before selecting, installing, or modifying lighting controls.

Combining Motion and Daylight High Bay Sensors