Series ERV Actuators are enhanced electrical actuators for hazardous NEMA 7, class I, Div. 1 Groups C and D; NEMA 9, class II, Div. 1, Groups E, F and G; and weatherproof NEMA 4 and 4X service. The ERV with a 75% duty cycle is available in 115 and 230VAC with standard motor brake, manual declutchable override and locked rotor protection. In addition, the modular design of ERV extends applicability with a variety of plug in circuits including: speed control, analog position transmitter, limit switch and communication modules, heater and thermostat for low temperature operation.