How to Zone UFO High Bay Dimming Controls

Large open spaces rarely need one blanket light level. Aisles, docks, mezzanines, and QC cells all have different tasks and code requirements. Zoning your UFO high bay dimming controls correctly is what turns a “bright warehouse” into a controllable, efficient, and code-aligned lighting system.

This guide focuses on 0–10 V dimming control for UFO high bays in warehouses, factories, hangars, barns, and large garages. The target reader is a facility manager, electrical contractor, or advanced DIY installer who wants practical rules that work in the field and stand up to inspection.

1. What “Zoning” Means for UFO High Bay Dimming

1.1 Zoning vs. simple switching

With hard on/off switching, every fixture on a circuit runs at 100% whenever that breaker or switch is closed. With zoning, you group fixtures so each group can be dimmed or switched independently, usually via 0–10 V control wiring and/or local sensors.

In practice, a “zone” is usually:

A group of fixtures sharing a 0–10 V control signal (and often the same branch circuit)
A defined area or task: e.g., pallet racks, loading docks, QC cells, packing lines, maintenance bays
Governed by a specific control strategy: manual dimmer, occupancy sensor, daylight sensor, or a combination

Most facilities end up with 6–20 zones depending on size and process complexity. The right number is less about square footage and more about how many distinct lighting behaviors you actually need.

1.2 Why zoning matters: codes, energy, and usability

Modern energy codes such as ASHRAE 90.1-2022 and the 2024 IECC commercial energy provisions require:

Multi-level lighting control (often 3+ steps or continuous dimming)
Occupancy-based control in many warehouse and storage areas
Daylight-responsive controls near skylights and windows

Zoned 0–10 V dimming is the simplest way to meet those requirements with UFO high bays. Codes also cap lighting power density, so pairing high-efficacy UFOs with good control zoning makes it easier to pass plan review and inspections.

On the usability side, zoning lets you:

Run bulk storage aisles at 20–50% while keeping docks, QC, and assembly at 70–100%
Dim back-of-house or night-shift areas to low “security” levels
Reduce complaints about glare by fine-tuning light levels per area

1.3 The control backbone: 0–10 V dimming

Most commercial-grade UFO high bays use 0–10 V dimming drivers. Per NEMA LSD 64, 0–10 V is a low-voltage control signal where:

10 V ≈ maximum output (100%)
1–3 V ≈ minimum dimmed light level (often 10–20%)
0 V may be minimum light or off, depending on driver design

A key practical detail is whether the driver provides a current source (active 0–10 V) or expects a current sink (passive). Mismatching a source-type dimmer with source-type drivers leads to unstable dimming, erratic behavior, or lights that never go fully bright or fully dim. Always verify the driver control type on the fixture label and spec sheet and bench-test a sample fixture with the intended controller before committing to a site-wide strategy.

2. Design Principles for Zoning UFO High Bays

2.1 Zone by task, not just geometry

A common mistake is to zone by building grid lines only (e.g., “Zone 1 is the north half, Zone 2 is the south half”). That looks neat on a drawing but rarely matches how people use the space.

In practice, you get better control and fewer complaints when you:

Group fixtures serving the same work process
Separate areas with very different target light levels or hours of use
Keep each zone large enough to be practical but small enough to matter

Typical task-based zones in industrial and warehouse environments:

Pallet rack aisles
Bulk storage / staging areas
Loading docks and exterior door bands
Picking / packing lines
Quality control and inspection areas
Maintenance bays and workshops
Mezzanines, catwalks, and office support areas

Advanced DIY shop owners can apply the same logic: separate zones for vehicle work bays, storage walls, and clean benches.

2.2 Practical zone sizes and fixture counts

For most 20–40 ft ceiling warehouses using UFO high bays, a practical zone size is 8–20 fixtures. Smaller zones increase flexibility but add cost and complexity in:

More 0–10 V homeruns or trunk lines
More sensor heads or wall controls
More points to troubleshoot later

Larger zones (>25–30 fixtures) tend to:

Over-light low-priority areas whenever any sub-area is occupied
Make occupant complaints harder to resolve (“I just want this one aisle brighter”)

A good rule of thumb from field projects:

Small warehouses (5,000–15,000 sq ft): 4–8 zones
Medium warehouses (15,000–60,000 sq ft): 8–16 zones
Large DCs and plants: 16+ zones, but driven by process, not square footage alone

2.3 Aligning zones with circuits and breaker sizing

Zones and branch circuits are related but not identical.

Best practice: Keep each lighting zone on a single branch circuit or panel section when possible. It simplifies lockout/tagout, troubleshooting, and emergency strategies.
Reality: In existing facilities, you may inherit mixed loads on a breaker. In those cases, rezone via low-voltage 0–10 V wiring even if the AC feed is shared, as long as fixture drivers support independent dimming.

When consolidating UFO high bays onto new circuits:

Calculate steady-state load (sum of fixture input watts / supply voltage) per circuit.
Account for driver inrush current, especially on large banks. For runs with >50 high bays on a breaker, use staggered relay energizing or soft-start contactors to avoid nuisance trips.

Always size conductors, overcurrent protection, and boxes per the applicable edition of the National Electrical Code (NEC) and local amendments. The NEC sets minimum safety requirements for wiring methods, overcurrent protection, and conductor fill; local code may be more restrictive.

2.4 Considering energy codes in your zoning plan

Energy codes define where you need controls and how granular those controls must be.

ASHRAE 90.1-2022 requires functional testing of lighting controls and mandates automatic shutoff in many commercial spaces.
The 2024 IECC commercial lighting chapter tightens lighting power density limits and expands requirements for occupancy and daylight-responsive controls.

In practice, this means your UFO high bay zones should, at minimum:

Provide multi-level or continuous dimming in most enclosed spaces
Separate areas near skylights or clerestory windows so they can be dimmed independently under strong daylight
Group together spaces that are unoccupied for long periods (e.g., seldom-used storage) so automatic shutoff yields real savings

If you work in California, layering this with Title 24’s warehouse control requirements is essential; for deeper detail, see the dedicated guide on Title 24 controls for high bay lighting.

3. 0–10 V Wiring and Control Topology

Once you know where your zones are, the next decision is how to run the 0–10 V control wiring and devices.

3.1 Source vs. sink: matching drivers and controls

Per industry practice and definitions summarized in NEMA lighting controls terminology, 0–10 V drivers generally fall into two categories:

Current-source drivers: The driver outputs a small DC current and expects the control device (dimmer, sensor) to sink it to vary the voltage.
Current-sink drivers: The control system provides the reference and sinks current from the driver or a separate supply.

Problems that show up when these are mismatched include:

Fixtures stuck at full brightness
Jumping or non-linear dimming
Some fixtures dimming while others in the same zone do not

Field-proven practice:

Check the fixture label and driver datasheet for 0–10 V type (often described as “current source, 0–10 V” or similar).
Confirm the control device is rated to work with that type and the total number of drivers per channel.
On new projects, bench-test at least one fixture with the chosen controller before wiring the whole building.

3.2 Class 1 vs. Class 2 control wiring

The NEC distinguishes Class 1 and Class 2 control circuits, each with different insulation, separation, and box-fill rules. The exact classification of your 0–10 V conductors depends on driver listing and system design.

Common field patterns:

Many commercial UFO high bays list their 0–10 V leads as Class 2 low-voltage control. These can often share raceways with branch-circuit conductors only if all conductors are rated for the highest voltage present and local code allows it.
Some engineers prefer to keep 0–10 V runs in separate cable (e.g., plenum-rated twisted pair) to simplify inspection and noise management.

Because misclassification can create inspection and safety problems, always:

Follow driver and control manufacturer instructions
Verify with the authority having jurisdiction (AHJ) if in doubt

3.3 Topology: daisy-chain vs. home run

You can wire 0–10 V control loops in several ways:

Daisy-chain within a zone: Run a single 0–10 V pair from controller to the first fixture, then loop through the rest.
- Pros: Less cabling, simpler routing.
- Cons: Harder to isolate a single fixture; any break in the loop can affect the rest of the zone.
Home run “star” topology: Run separate 0–10 V pairs from a central junction or controller to each fixture or small sub-group.
- Pros: Easier troubleshooting, better for very large or noisy environments.
- Cons: More cabling and terminations.

For most warehouses, a hybrid works well: daisy-chain in small clusters (4–8 fixtures) with home runs from each cluster back to a zone junction box or controller.

3.4 Noise, run length, and flicker control

Because 0–10 V is an analog signal, long runs and noisy environments can cause flicker or non-uniform dimming.

Field-tested practices:

Use a dedicated twisted-pair control cable, preferably shielded near motors, welders, or VFDs.
Avoid mixing 0–10 V conductors with high-current motor circuits in long parallel runs.
Keep unshielded 0–10 V runs under roughly 1,000 ft per channel in large warehouses to reduce noise pickup.

If flicker appears when big motors or cranes start:

Shorten runs or add intermediate junction boxes
Re-route control wiring away from high-noise feeders
Add or enable any available filtering options on the controller

3.5 Separation between 120–277 V “plug-in” UFOs and hardwired 0–10 V drivers

Another common mistake is mixing plug-in 120 V UFO shop lights and hardwired, 0–10 V–dimmable UFOs on the same dimmer or relay bank. The driver electronics and inrush behavior differ, which can:

Destabilize the dimming curve
Cause nuisance trips of breakers and contactors
Produce inconsistent light levels zone-to-zone

Best practice: treat non-dimmable or “plug-and-play” UFOs as separate zones and circuits from hardwired 0–10 V UFOs.

4. Step-by-Step: Designing Zoning for a Real Warehouse

To make this concrete, consider a 40,000 sq ft warehouse with 30 ft mounting height, racked to 24 ft, using 150–200 W UFO high bays.

4.1 Step 1 – Define target light levels and tasks

Start from recommended illuminance levels. ANSI/IES RP-7 suggests:

Bulk storage and low-activity aisles: often in the 20–30 foot-candle (fc) range
Active picking aisles and packing: often 30–50 fc or more
Precision work or QC: higher values depending on task criticality

Combine these targets with your own safety policies and any customer or regulatory requirements. You can also refer to the article on designing a high bay layout for warehouse safety for examples of how illuminance ties into accident reduction.

Map the floor by activity:

20 pallet rack aisles
2 bulk storage zones
4 dock doors with staging bands
2 QC cells
1 maintenance bay and 1 small fabrication corner

4.2 Step 2 – Sketch preliminary zones

Using task zoning principles:

Group every 2–3 aisles into one lighting zone
- 20 aisles → about 8–10 aisle zones
Combine bulk storage into a single low-priority zone
Make the dock and staging its own zone
Give QC cells and maintenance their own small high-output zones

This yields roughly 12–14 zones.

At this stage, confirm that each proposed zone can be physically fed by existing panels and that branch circuits can be arranged to roughly align with these zones.

4.3 Step 3 – Overlay control strategy on each zone

For each proposed zone, assign:

Control type: wall dimmer, occupancy sensor, daylight sensor, or integrated sensor/dimmer station
Default setpoint: typical dim level in normal operation (e.g., 80% in QC, 40% in aisles)
Schedule behavior: always on during shifts vs. vacancy-based (manual-on, auto-off)

Example configuration:

Zone type	Typical fixtures	Control device	Default dim level	Notes
Rack aisles	8–12 per zone	High-bay aisle occupancy sensors	30–60%	Time delay 10–15 min
Bulk storage	6–10	Occupancy sensors + manual override	20–40%	Long delay to prevent frequent cycling
Dock / staging	8–12	Wall station + occupancy	50–80%	Manual boost to 100% for inspections
QC / precision work	4–8	Wall dimmer (0–10 V) + local sensors	70–100%	Allow fine tuning by supervisors
Maintenance / fab bay	4–6	Wall dimmer + occupancy	60–100%	May need higher CRI and tighter control

You can find more detailed guidance on matching light quality (CRI, glare, etc.) to critical visual tasks in the article on high-CRI UFO high bays for QC areas.

4.4 Step 4 – Plan 0–10 V and power wiring together

Next, coordinate power and control:

Lay out branch circuits such that each circuit serves only one or two adjacent zones.
Route 0–10 V cabling following the same paths but with the separation rules discussed earlier.
For high rack aisles, route control cable along the rack tops or upper strut to minimize exposure to forklifts.

Create a wiring legend that clearly distinguishes:

Line-voltage lighting feeds
0–10 V control pairs
Sensor low-voltage power (if separate)

Label all conductors at junction boxes and fixtures. One of the most common field issues during maintenance is unlabeled control conductors that nobody wants to touch.

4.5 Step 5 – Commissioning in three passes

Real performance depends on commissioning. A practical three-pass process:

Baseline pass
- Turn all zones to 100%.
- Measure illuminance (lux or foot-candles) at representative work heights for each task area.
- Confirm you meet or exceed your design targets and applicable recommendations from standards such as RP-7.
Setpoint pass
- For each zone, dial down brightness until occupants and managers still feel comfortable and tasks are safe.
- Typical results: aisles end up at 40–60%; QC at 80–100%; bulk storage at 20–40%.
- Record the control setbacks and corresponding measured light levels.
Control behavior pass
- Program occupancy sensor time delays (often 10–20 minutes in warehouses, per DOE guidance on wireless occupancy sensors). The DOE warns that very short delays in high-bay spaces can cause frequent cycling and user frustration.
- Set daylight dimming curves in skylit areas so lights ramp down smoothly and do not “hunt” around setpoints.
- Test override switches and BMS integration where applicable.

Document the final settings and provide a simple one-page “lighting control summary” for operations. This is often required by energy codes and dramatically reduces future troubleshooting time.

5. Common Mistakes and How to Avoid Them

5.1 Myth: “All dimmable UFOs behave the same on 0–10 V”

A widespread misconception is that if a UFO high bay is labeled “0–10 V dimmable,” it will track perfectly with any other 0–10 V fixture. In reality, different driver manufacturers use different dimming curves, minimum levels, and response times.

In mixed-fixture retrofits, you may see:

One row going almost fully off at 1 V while another row stays at 30–40%
Some fixtures turning off entirely when the control line hits 0 V, others staying at their minimum

To avoid this:

Standardize drivers and fixture families wherever possible.
If you must mix, bench-test representative fixtures together and set realistic minimum levels (for example, 20–30% instead of 1%).
In bid specs, explicitly define dimming performance expectations rather than just stating “0–10 V dimmable.”

5.2 Oversized or undersized zones

Another common issue is zones that are either too large or too fragmented.

Oversized zones waste energy and create user frustration: turning on an entire half of a warehouse to unload one pallet.
Overly granular zones make for complicated control panels, confusing wall stations, and more failure points.

A practical test: if a supervisor cannot describe what each zone button or control does in one sentence, the system is probably over-zoned. Revisit the task grouping and merge low-priority areas where appropriate.

5.3 Ignoring luminaire documentation and listings

Specifiers sometimes ignore driver and fixture documentation, assuming “a UFO is a UFO.” For B2B and institutional projects, documentation is non-negotiable:

Safety: Verify that fixtures used in high-bay zones are tested to relevant safety standards such as UL 1598 for luminaires and, for LED components, UL 8750. These standards define construction, electrical, and thermal safety requirements for luminaires and LED equipment at up to 600 V.
Energy performance: For rebate-driven projects, check the fixtures on the DLC Qualified Products List. The DLC QPL is the primary reference utilities use to qualify high-bay luminaires for incentives; many programs specifically require DLC Standard or Premium listing for “high/low bay” categories.
Photometrics: Use LM-79 test reports or .ies files to verify lumen output, beam distribution, and efficacy. LM-79 is the IES-approved method for measuring optical and electrical performance of LED luminaires, and its data underpins DLC qualification.

Skipping these checks can lead to surprises at inspection time or during rebate application review.

5.4 Control wiring afterthoughts

On fast-track projects, 0–10 V wiring is often treated as an afterthought: added late, routed wherever there is space, and minimally labeled.

Consequences include:

Random flicker due to induced noise from adjacent power or motor feeders
Mix-ups when replacing fixtures, because nobody knows which 0–10 V pair controls which zone
Failed AHJ inspections if Class 2 requirements are not properly addressed

To avoid this:

Include 0–10 V topology and cable types in the original design documents.
Provide clear one-line diagrams and floor plans showing control wiring.
Label every junction box and control conductor with zone IDs.

5.5 Forgetting about future changes

Warehouses and plants reconfigure frequently. Racks move, mezzanines get added, and process lines shift.

When designing zones:

Keep some slack in 0–10 V cabling near structural elements so you can re-terminate later.
Use junction boxes at logical “break points” (ends of aisles, corners of process lines).
Avoid hard-tying multiple unrelated areas into a single zone; separate them so later reprogramming or partial rewiring is possible without major downtime.

6. Quick Zoning Checklist for UFO High Bay Dimming

Use this checklist during design and before commissioning:

Gather requirements
- Floor plan with current and future rack layouts
- Task descriptions and target light levels (referencing RP-7 where applicable)
- Energy code triggers (ASHRAE 90.1, IECC, and any local/Title 24 rules)
Define zones by task
- Assign separate zones to: rack aisles, docks, QC, maintenance, mezzanines, bulk storage.
- Aim for 8–20 fixtures per zone in typical high-bay applications.
Select control strategies
- Decide which zones use occupancy, daylight, manual dimming, or combinations.
- Set preliminary default dim levels for each zone.
Verify driver and control compatibility
- Confirm 0–10 V type (source vs. sink) and maximum driver count per channel.
- Bench-test a representative fixture with the chosen controller.
Plan wiring and documentation
- Coordinate branch circuits with zones as much as possible.
- Choose twisted-pair (and shielding where needed) for 0–10 V runs.
- Decide daisy-chain vs. star topology per zone.
- Label zones on drawings and in junction boxes.
Commission in three passes
- Baseline measurements at 100%.
- Dim to comfortable, safe setpoints per zone and record values.
- Program occupancy and daylight controls and test overrides.
Collect compliance evidence
- LM-79 report or .ies file for photometric verification.
- UL/ETL listings and FCC Part 15 statements.
- DLC QPL listings for rebate submissions.

For additional context on lumens-per-fixture decisions and avoiding over-lighting when you plan your zones, the warehouse lumens guide for UFO high bays is a useful companion resource.

Wrapping Up: Turn “Bright” into “Controllable and Compliant”

Good zoning turns a collection of UFO high bay fixtures into an integrated lighting system that saves energy, supports safety, and satisfies inspectors. The key is to think in terms of tasks and behaviors, not just rows of fixtures:

Design zones around how the space is used, not just geometry.
Match 0–10 V drivers and controls carefully, and treat low-voltage wiring as a first-class design element.
Size zones so supervisors can understand and operate them easily.
Commission in structured passes and document final settings.

By approaching UFO high bay dimming controls with the same rigor you apply to power distribution or fire protection, you build a system that is predictable, maintainable, and ready for future changes in codes, operations, and technology.

Disclaimer

This article is for informational purposes only and does not constitute professional engineering, electrical, or legal advice. Electrical work and lighting control design must comply with the National Electrical Code (NEC), applicable local codes, and relevant standards. Always consult a licensed electrician, professional engineer, or qualified design professional familiar with your jurisdiction and project conditions before modifying or installing any electrical or lighting control system.

How to Zone UFO High Bay Dimming Controls