What must be marked on equipment installed in hazardous locations?

In hazardous locations, it is essential that equipment is marked with its class, group, and temperature class to ensure safety and compliance with relevant codes and standards. This information helps to identify the types of hazardous materials that the equipment is designed to be used with, as well as its suitability for the specific conditions present in the environment.

The class indicates the general category of the hazard (such as Class I for flammable gases), while the group specifies the specific type of gas or vapor (for instance, Group A for acetylene). The temperature class provides the maximum surface temperature that the equipment can reach, which is crucial to prevent ignition of flammable substances around it. Proper marking of this information is vital for electrical professionals to select the right equipment for the right application, thereby ensuring the safety of both personnel and property in potentially explosive environments.

While other markings such as voltage rating, manufacturer details, and ingress protection rating are important, they do not specifically address the unique requirements for installations in hazardous locations where explosion protection is critical.