Attachment plugs and receptacles in hazardous locations must be listed for use in which class of locations?

Attachment plugs and receptacles used in hazardous locations must be specifically listed for the appropriate class of locations to ensure safety and compliance with electrical codes. In this case, Class I locations involve the presence of flammable gases or vapors, which can create explosive atmospheres.

Class I includes three groups based on the type of hazardous materials present. Group C specifically deals with flammable gases, such as ether, acetylene, and hydrogen, which require stringent safety measures. Devices used in these environments must be designed and tested to prevent ignition and ensure safe operation.

Thus, attachment plugs and receptacles intended for use in Class I, Group C locations need to be listed for those specific conditions, as they must effectively reduce the risk of igniting flammable gases. This requirement underscores the importance of using equipment that is certified for use in such potentially dangerous environments, ensuring both compliance with safety standards and the protection of personnel and property.