Processing Magazine

Electric actuators earn ATEX certification

November 12, 2009
The electric actuator features a die-cast aluminum alloy enclosure bolted together in two sections by eight M8 hex head cap screws and fitted with an O-ring between the two halves for environmental purposes. Access to the enclosure is by two M20 conduit openings in the base. The main shaft, which penetrates through both sides of the enclosure, forms the flameproof enclosure. The shaft top is connected to a visual beacon position indicator and is covered by an upper knob, which is pulled upward to put the actuator into manual override mode. The internals of the actuator feature a reversing type 120 vac or 230 vac capacitor-run reversing type motor. A thermal overload protection sensor is embedded in the motor windings and is designed to prevent motor failure. The motor features a permanently lubricated gear train and hardened steel spur gears. Two end-of-travel limit switches are mechanically set via adjustable cams for open and close positions. Accessories such as 4-20 Ma positioners, single and double extra limit switches, heater and thermostat, cycle length control modules, two-wire control relays, and electro mechanical brakes are all available factory installed and calibrated in the actuators.