Environmental Technologies Air Terminal Unit SDR-19

Mechanical Angle of Rotation Stops

Loosen the two end stop screws using a No. 2 Phillips head screwdriver

Ensure not to unscrew the captive nut under the slot

Move the stops to the desired position (in 2.5° steps)

Disconnect all electrical power to the equipment, tag and lock out power source.

Gain access to coil either through ductwork or optional coil access panel.

Use soft brush and vacuum to remove loose debris from sides of coil.

Straighten any coil fins that may have been damaged during cleaning process with fin comb.

Replace ductwork or access panel and restore electrical power to equipment.

Disconnect actuator from the controller

Apply 24 VAC to the COM and CW terminals on the actuator. Does the actuator rotate in a clockwise direction?

Apply 24 VAC to the COM and CCW terminals on the actuator. Does the actuator rotate in a counter clockwise direction?

Does the actuator move in both directions, indicating it is operational?

If the actuator does not rotate, is it at an end stop or is there a problem with the damper?

Loosen the set screw to free the actuator from the damper shaft

Check to make sure that the damper shaft rotates freely

Check to make sure that actuator is not against stop. Repeat steps 2 and 3.

Refer to the 'Electric Heat, All Products' IOM for complete electric heater installation, operation and maintenance information.

Check the primary auto-reset limit switch for proper operation.

Inspect the secondary one-time trip limit switch for tripping.

Replace the secondary limit switch if it has tripped, ensuring the new switch has the same trip temperature as the original.

Check if an optional manual reset secondary is installed and reset if necessary by depressing the reset switch.

Verify airflow is at least 70 CFM per kW.

Ensure a minimum of 0.1" w.g. external pressure is maintained.

Ensure all electrical work is finished and properly terminated.

Verify all electrical connections are tight and the proper voltage is connected.

Measure AC power imbalance (should not exceed 2%).

Is AC power within 10% of rated voltage at rated frequency?

Is AC power within 5% of rated frequency at rated voltage?

Is the combined variation in voltage and frequency within 10% of rated values, with frequency variation not exceeding 5%?

Ensure equipment with electric heat has a minimum of 0.1" w.g. downstream static pressure.

Obtain and understand the project control sequence/wiring diagram prior to start-up.