Data Sheet for Product

Technical Instructions OpenAir GMA Series, Spring Return, 62 lb-in Rotary, Electronic Damper Actuators
Document Number 155-315P25
March 6, 2018
Page 8 Siemens Industry, Inc.
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
AreaDamperRatingTorque
1
×
4. Select a spring return actuator using Table 2.
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.
NOTE: Mechanically coupled actuators must be of the exact same type except
for the dual auxiliary switches and feedback potentiometer options. Use
the correct mounting bracket. See Table 2.
Table 2.
DC Power (24 Vdc)
AC Power (24 Vac, 120 Vac)
Total Torque
Actuator
Total Torque
Actuator
<62 lb-in (7 Nm)
GMA1xx
<62 lb-in (7 Nm)
GMA
>62 lb-in <160 lb-in
(>7 Nm <18 Nm)
GCA12x, GCA13x, GCA15x*
>62 lb-in
<160 lb-in
(>7 Nm <18 Nm)
GCA
>160 lb-in <320 lb-in
(>18 Nm <36 Nm)
Use tandem mounting bracket
ASK73.1 with any combination
of:
• GCA12x actuators
• GCA13x actuators
Use tandem mounting bracket
ASK73.2U with any
combination of GCA151 and
GCA156 actuators.*
>160 lb-in
<320 lb-in
(>18 Nm <36 Nm)
Use tandem mounting bracket ASK73.1
with any combination of:
• GCA12x actuators
• GCA22x actuators
• GCA13x actuators
• Use tandem mounting bracket
ASK73.2U with any combination of:
• GCA151 and GCA156 actuators*
• GCA161 and GCA166 actuators