Why Fixed-Wattage Lighting Is Becoming a Limitation
Traditional outdoor and commercial lighting design has relied on fixed-wattage fixtures paired with detailed photometric layouts. While effective on paper, this approach often fails to account for real-world variables such as field conditions, pole spacing deviations, reflectance changes, and evolving use of the space.
Selectable wattage—often referred to as power-tuning—allows installers and facility managers to adjust lumen output on-site. This capability is changing how lighting systems are specified, commissioned, and optimized after installation.
What Selectable Wattage Actually Means
Selectable wattage fixtures incorporate drivers that allow multiple preset power levels to be selected via a switch, dip selector, or control interface. Each wattage setting corresponds to a defined lumen output verified by the manufacturer.
| Characteristic | Fixed-Wattage Fixture | Selectable Wattage Fixture |
|---|---|---|
| Output flexibility | Single lumen package | Multiple field-selectable levels |
| Commissioning adjustment | Not possible | Performed on-site |
| Future adaptability | None | Supports changing site needs |
This flexibility shifts part of the design decision from the drawing set to the installation phase.
How Power-Tuning Changes Lighting Design Workflows
With fixed-output fixtures, designers must finalize lumen packages before installation. Any deviation in field conditions often requires fixture replacement or acceptance of suboptimal results.
Selectable wattage changes this workflow by allowing:
- Initial installation at higher output for commissioning
- Final adjustment based on measured foot-candle levels
- Post-install optimization to address glare or over-lighting
| Project Phase | Fixed-Wattage Approach | Selectable Wattage Approach |
|---|---|---|
| Design | Exact lumen package locked | Range defined |
| Installation | No adjustment possible | Initial tuning allowed |
| Post-install | Replace fixtures if incorrect | Adjust output on-site |
This reduces risk when translating photometric intent into real-world performance.
Photometric Layouts vs. Field-Adjustable Output
Photometric layouts remain essential for establishing pole spacing, optic selection, and uniformity targets. However, selectable wattage reduces the need for overly precise lumen assumptions.
| Design Aspect | Traditional Layout | Power-Tuned Layout |
|---|---|---|
| Lumen accuracy | Critical | Adjustable |
| Tolerance for site variance | Low | High |
| Risk of over-lighting | Higher | Reduced |
The result is fewer redesigns and less reliance on idealized assumptions.
Where Selectable Wattage Delivers the Most Value
Selectable wattage is particularly valuable in projects with uncertain or evolving conditions.
| Application | Why Power-Tuning Helps |
|---|---|
| Parking lots | Adjust output for glare and uniformity after install |
| Warehouses | Tune light levels based on racking height |
| Retrofit projects | Unknown reflectance and layout conditions |
| Multi-phase developments | Future-proof for site changes |
In these cases, power-tuning reduces both upfront risk and long-term modification costs.
Limitations and Design Considerations
Selectable wattage does not eliminate the need for competent lighting design.
- Optic selection remains fixed
- Over-spacing poles cannot be corrected by higher wattage alone
- Thermal and surge ratings must align with the highest wattage setting
| Consideration | Why It Matters |
|---|---|
| Maximum wattage setting | Defines thermal and driver stress |
| Controls integration | Must coordinate with dimming systems |
| Documentation | Final wattage should be recorded for maintenance |
Power-tuning is a corrective tool, not a substitute for layout discipline.
Common Mistakes When Using Selectable Wattage
- Leaving fixtures at factory default without field verification
- Using wattage increases to compensate for poor spacing
- Failing to document final settings after commissioning
- Ignoring energy code implications of higher wattage settings
Most issues arise from treating selectable wattage as an afterthought rather than a design feature.
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Selectable wattage is reshaping how lighting systems are specified and commissioned. By allowing controlled adjustment after installation, power-tuning reduces risk, improves performance alignment, and minimizes the need for complex redesigns when real-world conditions differ from the plan.
Frequently Asked Questions
How do PIR sensors detect movement?
PIR (Passive Infrared) sensors detect changes in infrared radiation—essentially, they look for moving heat signatures (like a person or a warm forklift engine). They are line-of-sight devices. If a racking upright or a pallet is between the sensor and the worker, the sensor will not trigger. This makes them highly precise but sensitive to physical obstructions.
What makes Microwave (Doppler) sensors different?
Microwave sensors emit low-power radar pulses and measure the Doppler shift as they bounce off moving objects. Unlike PIR, they do not care about heat; they only care about motion. Because these radio waves can penetrate thin materials, microwave sensors can often detect a forklift approaching from around a corner or through a plastic curtain, providing a pre-lit path for the driver.
Which sensor is better for high-ceiling (40ft+) applications?
As mounting height increases, PIR sensitivity typically decreases because the heat signature becomes smaller and harder to distinguish from the floor temperature. Microwave sensors generally maintain better sensitivity at high mounting heights (above 30 feet). However, for very high ceilings, you must ensure the PIR sensor is specifically rated for High Bay use with specialized lenses designed to focus the infrared zones over long distances.
Why do Microwave sensors sometimes cause Ghosting?
Ghosting refers to lights turning on when no one is in the aisle. Because Microwave sensors can see through thin walls and glass, they may detect activity in a neighboring aisle or even large fans and HVAC vibrations. If your warehouse has thin metal racking or high-velocity fans, PIR is often the safer choice to prevent these false triggers and wasted energy.
Can I use PIR sensors in cold storage or unconditioned space?
PIR sensors struggle when the ambient air temperature is close to human body temperature (approx. 98°F), as there is no thermal contrast to detect. In very hot warehouses, PIR performance drops significantly. Conversely, in cold storage, PIR works exceptionally well because the contrast is high. Microwave sensors are independent of temperature, making them a reliable all-weather option for dock doors and non-climate-controlled zones.
Brandon Waldrop
As the lead technical specialist for our commercial lighting technical operations, Brandon Waldrop brings over 20 years of industry experience in product specification, outside sales, and industrial lighting applications.
His career began in physical lighting showrooms, where he focused on hands-on product performance and technical support. He later transitioned into commercial outside sales, working directly with architects, electrical contractors, and facility managers to translate complex lighting requirements into energy-efficient, code-compliant solutions.
Today, Brandon applies that industry experience to architect high-performance digital catalogs and technical content systems, helping commercial partners streamline the specification process and deploy lighting solutions with total technical confidence.