The National Electric Code defines a hazardous duty location as a location in which gases or vapors are, or may be, present in the air in quantities sufficient to cause explosions or ignitable mixtures. Such atmospheres can include substances such as gasoline, petroleum, naphtha, acetone, lacquer, solvent vapors, or natural gas. Equipment operating in such locations must be designed so that there is no possibility that its operation can ignite flammable gases. One electrical switchgear manufacturer facility has addressed this problem by using the Electrak 2000 linear actuator, which was designed for operation in hazardous duty locations. The actuator is being used to open and close the doors of a booth in which the switchgear casings are painted.
Air handling equipment removes virtually all paint fumes from the booth.
Although there is a relatively small risk of the remaining fumes igniting, hazardous-duty equipment still is required in this location. The actuator is equipped with a step motor that can handle a dynamic load of up to 625 pounds at 1.5 inches per second, and has a speed of up to 20 inches per second at 50 pounds. For constant-speed motion and cycling applications where programmability is not required, the actuator can include an ac synchronous motor. The ac motor version can handle a dynamic load of up to 650 pounds at 0.2 inches per second and has a speed of up to 0.6 inches per second at 250 pounds.