ELECTRICAL WORK PRACTICES

Hazardous (Classified) Locations - Precaution

Despite the hazards of a location, every precaution must be taken to guard against ignition of the atmosphere. Certainly no open flames are permitted in these locations. Electric equipment capable of igniting flammable materials or gases shall not be used, unless measures are taken to prevent hazardous conditions from developing.

There are many ways in which electrical equipment can act as a source of ignition in a hazardous location:

Switches, circuit breakers, motor starters, contactors, plugs, and receptacles all release arcs and sparks as contacts open and close during normal operation

Lighting fixtures and motors are classified as "heat producing". They will become a source of ignition if their surface temperature exceeds the ignition temperature of the flammable material or gas

An abnormality or failure in an electrical system, such as the failure of insulation, can release sparks, arcs, or heat.

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