It is very important to carefully evaluate the hazardous and operational conditions, before actually ordering industrial electrical enclosure and panel. Apart from securing your components, electrical enclosures also impact the security of those in the vicinities and surroundings. Operators, staff/employees, and many other people may be adversely affected when an improper electrical enclosure with an incorrect rating has been installed.
The basic steps for finding out the current electrical enclosure for an operational environment where hazardous gases are always present include:
•Finding out the NEMA environment rating.
•Determining and finding out the NEC (National Electric Code) explosion protection classification.
•Knowing more about the pressurization and purge type.
•Finding out and specifying the electrical enclosure with the right rating.
Remember that customization and modernization are necessary, and there will be no “one size fits all” solution available for electrical enclosures.
NEMA 4 and 4X Enclosures
The NEMA 4 and 4X electrical enclosures for Class 1 and Class 2 hazardous environment should be customized so that they can overcome the hazardous threats. Electrical enclosures with a NEMA rating of 4 are basically watertight. These electrical enclosures can also resist the formation of ice, dust blown weather, cold conditions, and can also resist hose-directed water and splashing. The 4X variety has additional resistance to corrosion. Therefore the 4X enclosure can only be made of aluminum or stainless steel.
The Hazardous locations may have flammable water vapors and gases, combustible gases and vapors, and/or ignitable vapors present in the atmosphere. The National Electric Code (NEC) classifies the hazardous areas into various zones, divisions, and classes. The Class 1 Division 2 areas only have the flammable liquids, gases, and vapors present in an abnormal condition. But the flammable elements are present in Class 1 Division 1 conditions on a regular scale, and at all the times.
While a leading manufacturer of electrical enclosures will provide you an enclosure with the right NEMA rating, the company will not be able to certify enclosure in accordance with the NEC explosion protection criteria. The operation conditions differ and hence proper customization of the enclosure is necessary before its installation.
Containing the Threat of Explosion
For an explosion to occur in a hazardous environment, the 3 important elements that should be present include heat, oxygen, and flammable substance/fuel. To prevent an explosion, the internal explosion can be contained, or one or more than one of the necessary components for the explosion to occur should be removed.
Pressurization and Purging
Pressure can be created within the enclosure (by using clean or some inert air). This will prevent outside air (containing flammable vapors/gases) to reach the inside of the enclosure. A purge control system and a gasket will create an impregnable seal. Such enclosures have the interlock feature through which access can be provided to their interiors. The NFPA (National Fire Protection Association) has the classification of the pressurization systems. They can be Type X, Type Y or Type Z. These systems vary in the kinds of equipment they can store, the features and capabilities they have, and the divisions in which they can be used.
Customization of the Electrical enclosure in Class 1 Division 2 Environment
The Class 1 Div 2 enclosure may use the right materials and components so that it can overcome the effects of temperature, have the right pressure, and prevent the entrance of the flammable gases to the insides. They are created using the matching gaskets, hinges, cutouts, mechanical interlocks, timer mountings and other kinds of components.
You can consult a reputed supplier/manufacturer of electrical enclosures to have the best solution that can well suit the demands of your particular operation and hazard environment.