Product Overview
OpenAir Spring Return 20 lb-in, Rotary GQD Series Electronic Damper Actuators Technical Instructions
Document Number 155-760
June 23, 2008
Siemens Building Technologies, Inc. Page 5
Operation
GQD151
Apply a continuous 2 to 10 Vdc control signal between wire 8 (Y) and wire 2 (G0) to
operate the damper actuator. The angle of rotation is proportional to the control signal.
A 2 to 10 Vdc position feedback output signal is available between wire 9 (U) and wire 2
(G0) to monitor the position of the damper motor.
In the event of a power failure or when the operating voltage is shut off, the actuator
returns to the "0" position.
GQD121/GQD221.1U
When power is applied, the actuator coupling moves toward the open position "90°". In
the event of a power failure or when the operating voltage is shut off, the actuator returns
to the "0" position.
GQD131
A floating control signal controls the damper actuator. The actuator's angle of rotation is
proportional to the length of time the signal is applied. A 24 Vac/dc control signal to wire
6 (Y1) causes the actuator coupling to rotate clockwise. A 24 Vac/dc control signal to
wire 7 (Y2) causes the actuator coupling to rotate counterclockwise.
With no control voltage, the damper actuator holds its position. In the event of a power
failure, the actuator will return to the "0" position.
Overload Protection
In the event of a blockage in the damper, the actuator is overload protected over the full
range to prevent damage to the actuator.
Life Expectancy
An improperly tuned loop will cause excessive repositioning that will shorten the life of
the actuator.
Sizing
The type of actuator required depends on several factors:
1. Obtain damper torque ratings (lb-in/ft
2
or Nm/m
2
) from the damper manufacturer.
2. Determine the area of the damper.
3. Calculate the total torque required to move the damper:
Total Torque =
SF
AreaDamper Rating Torque
1
×
4. Select a spring return actuator using Table 1.
1
Safety Factor: When calculating the total torque required, a safety factor should be
included for unaccountable variables such as slight misalignments, aging of the
damper, etc. A suggested safety factor is 0.80.