Industrial work sites are filled with dangerous elements that could damage costly, unprotected equipment. The presence of corrosive cleaning agents is a great example, forcing luminaries to fail prematurely or tools to malfunction. Furthermore, in hazardous locations, volatile gases could penetrate electrical components of industrial lighting systems and cause unwanted ignitions.
To prevent such issues, lighting manufacturers seal luminaries in a hermetically, airtight manner. Read on to understand how hermetically sealed units improve illumination in industrial facilities.
Hermetically sealed lights prevent hazardous elements, which could be gases, liquids or dust, from entering the units. In most cases, this type of enclosure is used to loosely describe specifications or testing grades.
The NEC refers to this term as a technique for protecting the internal components of lighting systems. According to NEC Sec. 500.7(J), hermetic sealing is achieved via welding, fusion or soldering. Additionally, hermetically sealed is not limited to luminaries. It can be used to describe a plethora of explosion proof machines designed for hazardous locations, including HVAC systems and small switches.
Hermetic seals can consist of epoxy resins to maximize effectiveness. The substance is capable of tightly bonding two similar elements, reducing gas leaks with temperature thresholds between -70 degrees Celsius and 150 degrees Celsius. It is also possible to hermetically seal glass and metal together, which is typically used for industrial lights in non-hazardous environments.
What About Factory Sealed?
Contrary to popular belief, hermetically sealed industrial lighting is not the same as factory sealed lighting. Although the two techniques share similar goals, the latter method does not use the same sealing practices, as the contacts in the explosion proof enclosure of a factory sealed unit are molded inside. Factory sealing is considered to be cost effective and common in Class I, Division 2 industrial facilities.
It’s important to highlight that factory sealed equipment are typically suitable for Groups C and D hazardous locations – not Group B (hydrogen, with an ignition temperature of 968 degrees Fahrenheit). For more information please visit http://www.larsonelectronics.com/