Modulating Actuator Motor
DMA Series

Technical description
The DMA actuator drives from 0° to 90° via a 4 to 20 mA input signal. It can move in any direction and stop anywhere over the entire 90° stroke. The field adjustable stroke is factory set at 90° and the position is factory set at 0°. The DMA is available in three different set speeds: 6 s, 12 s or 30 s.

The DMA has one independent, field adjustable auxiliary SPDT switch and two field adjustable limit switches.

During power interruption, the acutator will remain stationary. After power is restored, the position is determined by the controller input signal. However, if the 4 to 20 mA signal is interrupted and the DMA is still powered, the actuator will drive fully CW (towards 0°), which will close the DMK butterfly control valve.

4 to 20 mA feedback can be used to drive a slave motor (3 actuators maximum in parallel).

Maximum stroke (Y max; span) is adjustable from 25° to 90°, and minimum stroke (Y min; zero) is adjustable from 0° to 75% of the set span (maximum stroke).

Application
When mounted on the DMK butterfly control valve, the DMA is used to automatically modulate the amount of natural gas, butane, propane and/or air supplied to the burner.