Benefits of Explosion Proof Plugs and Cords|
Article - February 14, 2016 By LarsonElectronics.com
Benefits of Explosion Proof Plugs and Cords
Hazardous locations, where combustible gases, vapors and dust are present, require explosion proof or intrinsically safe equipment to prevent catastrophic accidents. In addition to explosion proof fixtures, operators must use explosion proof extension cords and plugs for complete protection in the workplace.
Advantages of Explosion Proof Cords
Explosion proof cords are used to extend the reach of stock equipment cables in a hazardous location. They also provide the ability to turn fixtures without switches, such as drop lights, on and off. This can be done instantly using an inline switch on the cord, without needing to walk to the power source. “The primary problem with such cords and connections is that, every time the device is connected and disconnected, it is possible for arcing and sparking to occur at the point of connection,” said Robert Bresnahan, CEO of Larson Electronics, in a report for Industry Safety and Hygiene News.
To prevent such occurrences, it is best practice to connect the explosion proof cord with the respective equipment outside of the hazardous location. This is to ensure that sparking that may arise from the initial connection does not ignite any combustible compounds that may be present in the facility. After connecting the two components, one should be able to use the equipment safely.
NEC and SOOW Compliance
Explosion proof cords must adhere to guidelines from the National Electric Code (NEC) for proper application in hazardous locations. Article 500 in the code elaborates on the details of each hazardous location classification, division and grouping. Businesses must match the explosion proof cord classification rating with the appropriate hazardous location.
For example, if an explosion proof cord is approved for Class 1 Division 1 (C1D1), it can be used in hazardous locations where flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors may be present in amounts that could produce an explosion or ignition. Petroleum refineries and chemical processing plants are examples of facilities that are categorized under C1D1. Furthermore, equipment approved for Division 1 may be used in Division 2 environments (as long as it is in the same class and group). More information about each classification can be found in the NEC.
Some explosion proof cords come with SOOW approval ratings. This simply refers to the properties of the equipment. They are used in heavy-duty industrial applications, where flexibility and durability is required. Such units with SOOW ratings offer superior resistance against oils, acids, chemicals, water and extreme temperatures. The cords are also sunlight resistant and flame retardant.
SOOW cords meet the following regulatory standards:
• UL Flexible Cord Subject 62
• CSA Flexible Cord C22.2-49
• MSHA Approved
• RoHS Compliant
• OSHA Acceptable
SOOW cords are built to operate between -40 to 90 degrees Celsius. The acronym stands for the following properties:
• S: Service Cord (600 Volts)
• OO: Oil Resistant both inside insulation and outside jacket
• W: CSA designation for weather/water resistance
Explosion Proof Plugs
Explosion proof plugs are designed to prevent sparks from escaping the unit, where it can ignite combustible compounds. Like explosion proof lights, such plugs come with specific ratings that dictate its application in hazardous locations. To reduce the risk of combustion, an explosion proof plug may use non-sparking aluminum for its housing and recessed brass pins to prevent accidental contact. A locking collar may also be applied to keep the plug connected to the equipment at all times during operation.