Optics, Light Quality and Lenses

Optics that direct light where you need it

LEDs are highly directional, making them an excellent choice for precise area and task lighting in hazardous and heavy industrial environments. The optics design of an LED luminaire plays a critical role in providing efficient and optimized light distribution for individual applications. Look for luminaires with secondary optics available in specific beam patterns, as this will help eliminate gaps and dark spots, as well as reduce the number of light fixtures required in your application. Secondary optics will also reduce glare, ideal for applications which need constant human interface such as control rooms and monitoring stations with reflective computer screens.

Standard classification systems for light distribution patterns exist to help lighting designers and specifiers select the proper luminaire for their application. For area and roadway applications, the Illuminating Engineering Society of North America (IESNA) introduced a system of lighting “Types” that makes it easy to identify a fixture’s distribution pattern. Floodlights and spotlights utilize a standard from the National Electrical Manufacturers’ Association (NEMA), which classifies a fixture’s horizontal and vertical light spread.

Below are common secondary optic beam patterns used across our LED portfolio, along with the types of industrial applications they are best suited for.

Selecting the right optic for your application can have a significant impact on your investment

A real world example

The lighting layouts below were developed by the Lighting Design team at Eaton’s Crouse-Hinds Division for a cryogenic processing plant looking to eliminate dark areas on walkways underneath their pipelines. As you can see, our VMV LED luminaires with Type I optics delivered a linear beam pattern along the work plane, eliminating gaps and dark spots. And, because our optics distributed the light where it was needed most, the facility was able to reduce the necessary fixture count by 30% and realize significant savings on the overall lighting upgrade.

Color temperature, color rendering and footcandles

To ensure that an LED luminaire will provide high quality lighting, it’s critical to understand and evaluate these three key measurements.

Color Rendering Index (CRI) - Per the Illuminating Engineering Society of North America, color rendering indicates the degree to which a light source shows the true colors of the objects it illuminates. It is expressed on a scale of 0-100. The higher the CRI, the truer people and objects will look. Though not required for every industrial lighting application, a high CRI is typically considered beneficial.

CRI values for industrial LED luminaires will vary by manufacturer due to the components used. Our recommendation is to select luminaires with a CRI value of 70 to 80, as this will provide accurate color and a safe work environment for performing precision tasks.

Correlated Color Temperature (CCT) - Color temperature refers to the degree of yellowness or blueness in the illumination hue. This is the “look” of the light, and it is measured in Kelvin. Ratings at the lower end of the Kelvin scale (~2000-3000K) are more yellowish in color and are referred to as “warm white”.

LEDs at the higher end of the scale (5000K+) are typically white to light blue in color and referred to as “cool white”.

Because desired color temperature varies by application and customer preference, a reliable manufacturer will offer several color temperature options across their LED families.

Footcandles - Often with LED luminaires a heavy emphasis is put on lumens (the total amount of light output from a specific angle). However, this can be misleading. With LED being such a directional light, it requires fewer lumens than traditional light sources. Even when comparing LED fixtures across manufacturers, luminaire construction and optics play a major role in producing productive light, and a pure lumen-to-lumen comparison is not always relevant.

Instead, designers and specifiers should focus on a fixture’s footcandles, which measures the usable light on the work plane.

Footcandle readings tell you the amount of light actually illuminating the various areas of your installation.

Dark Sky Friendly by design to minimize light pollution

According to the International Dark-Sky Association (IDA), light pollution is the inappropriate or excessive use of artificial light, and it can have serious environmental consequences for humans, wildlife, and our climate. Light pollution is made up of 4 primary components:

• Glare – excessive brightness that causes visual discomfort
• Skyglow – brightening of the night sky over inhabited areas
• Light trespass – light falling where it is not intended or needed
• Clutter – bright, confusing and excessive groupings of light sources

To combat light pollution, the IDA and Illuminating Engineering Society have developed Five Principles for Responsible Outdoor Lighting. Applying these principals to your design will help ensure that your lighting installation is functional while minimizing light pollution and wildlife disruption.

We offer 4 to 6 KV with drivers that are field replaceable, and recom- mend additional surge protection to be handled in the panel.

Crouse-Hinds series LED luminaires are Dark Sky Friendly by design

Below are few of the solutions we offer to help reduce light pollution and improve quality of life.

Driver design & field replaceability

Drivers are used to power a luminaire’s LEDs by stepping down the incoming voltage and converting it from AC to DC. They also protect the LEDs from fluctuations in current and voltage. Drivers are a critical component in the overall efficiency and longevity of a lighting fixture.

When evaluating harsh and hazardous LED luminaires for your installation, be sure to check the power factor and total harmonic distortion (THD) of the driver.

Power factor (PF) measures how much energy is converted into useful power in the LED driver, and it’s identified by a number between 0 and 1. The higher the number, the more efficiently the driver is using electricity. We recommend using luminaires with a power factor of 0.90 or higher.

Total Harmonic Distortion (THD) indicates how efficiently the driver minimizes interference to other electrical equipment, and it should be as low as possible. A low THD indicates higher power factor, lower peak currents and temperatures, and higher efficiency.