Comparing Lighting Capabilities of Explosion Proof Luminaries|
Article - February 9, 2016 By LarsonElectronics.com
Comparing Lighting Capabilities of Explosion Proof Luminaries
Explosion proof lights are essential for businesses that work with and around hazardous compounds. These days, there are numerous types of explosion proof luminaries available on the market. Such options range from handheld flashlights and drop lights to high bay fixtures and light towers. Additionally, customers must choose from a handful of lighting technologies that come with their own unique set of advantages and characteristics.
This article compares the following explosion proof lights for use in hazardous locations: Explosion Proof LED Flood Light Fixture (EPLC2-LED-2X150W-RT-140DB-480V) and Explosion Proof High Pressure Sodium Light (HALPRM-1000WHPS).
Light Output and Layout
During light output, the explosion proof LED fixture emits a narrow, intense flood pattern beam with a brilliant white color (3,000K, 4,500K and 5,000K color temperature ratings). It also produces colors accurately with a Color Rendering Index rating of 70. The fixture can produce 35,000 lumens while drawing 300 watts. This luminary comes with a failsafe feature that can boost the general lifespan of the unit. It comes with multiple LED drivers and 24 individual LED boards that ensures parts of the lamp continues working in the event of driver failure. Voltage options for the LED lamp includes 347-480V AC, 50/60Hz (multi-voltage capable).
The explosion proof HPS lamp also supports a flood pattern configuration during output, and offers wider coverage than the LED fixture via parabolic reflectors inside the unit. It is important to consider that most HPS luminaries emit a yellowish white, low color temperature-rated beam. They are also known for producing low CRI values at roughly 25 CRI. This unit produces 125,000 lumens during light output, while drawing 1,000 watts. Voltage options include 120V, 208V, 240V, or 277V / 220-480 OPT. The HPS lamp is also considerably lighter at 45 lbs., compared to the LED fixture at 70 lbs.
When comparing light produced by the units (mounted 50 feet Above Finished Floor [AFF] with a 45-degree tilt), the LED fixture generates a circular shape with an intensely lit center. The HPS lamp emits an oblong-like beam that is wide and its intensely lit center also takes on a similar, oblong-like shape. Inside the beam, both lights produce up to five foot candles and up to eight foot candles of illuminance for the center. Outside the beam, both units leak around 1-2 foot candles of light, with the LED fixture producing a tighter beam, compared to the HPS lamp.
Hazardous Location Features and Applications
Both lamps are designed for use in hazardous locations. The explosion proof LED fixture comes with Class 1 Division 2 (Groups C and D), Class 2 Division 1/2 (Groups E, F and G) and Class 3 ratings from the National Electric Code (NEC). It supports a copper-free, aluminum alloy body that improves the durability of the fixture when exposed to vibration, rough treatment and impacts. This LED luminary is ideal for paint spray booths, gas stations and petroleum refineries. Mounting options for the light includes the following: pendant, ceiling, wall and cable.
The explosion proof HPS lamp is suitable for hazardous locations associated with Class 1 Division 2 (Groups A, B, C and D) ratings from the NEC. It can also sustain maximum operating temperatures up to 325 degrees Celsius (T1 NEC Identification Number). The housing of the unit consists of pressure cast, copper-free aluminum with a deep bronze Polyester finish, impact-resistant door glass, and high temperature silicone rubber seal. All of these components combined reinforces the weatherproof properties of the fixture. This HPS lamp is suitable for hazardous locations, outdoor environments, industrial locations and marine applications- due to its corrosion resistant features. Mounting options for the luminary includes the following: slip fit pole and zinc-plated yoke.
LEDs vs HPS Lamps
The lighting technologies used in both lamps differ greatly. HPS luminaries rely on high temperatures, an arc tube and a mixture of gases to produce light. With an average lifespan of 24,000+ hours, the fixtures are generally reliable, because they can maintain 90 percent of light output at the midpoint of their intended lifespan. At the end of the unit’s lifespan, it can still generate up to 80 percent output. LEDs utilize tiny diodes to produce intense lighting conditions and support a lifespan of 50,000+ hours. It can handle instant toggling- a feature that HPS lamps do not have. Hence, operators that use HPS fixtures must wait for a short period of time when warming up the lamp from a non-operational state, and when restarting the fixture from an operational state.
LEDs generate very little heat during output and emit light for 180 degrees. On the other hand, HPS fixtures emit light in all angles (360 degrees), requiring manufacturers to install reflectors that direct light beams to the desired target.
From a long-term perspective, LEDs come with almost zero maintenance costs but initial purchasing costs tend to be higher, compared to traditional luminaries. HPS lamps are prone to breakage due to loose components inside the bulb and its strong reliance on ballasts. Because of this, customers using HPS fixtures will need to consider additional investments, such as replacements for expired components and unforeseen labor costs.