Basic Documentation
19/44
Siem ens GMA..1 actuators with spring return CM2Z4614en
Building Technologies 2018-01-11
The following diagram (example EMCO) allows for determining the total torque for this
air damper type.
10
9
8
7
6
5
4
3
2
1
0
200 400 600 800 1000 1200 1400 1600 1800 2000
1
9
9
5
1
6
6
5
3
4
5
20
1600
1200
800
15
400
15105
105
2010
10
2
0
0
0
1
0
0
0
0
1
0
0
5
1
3
3
5
6
7
5
D
a
m
p
e
r
h
e
i
g
h
t
H
[
m
m
]
Friction torque (without air influence) [Nm]
Damper width B [mm]
Total torque [Nm]
Damper width B [mm]
4614D02en
T
o
t
a
l
p
r
e
s
s
u
r
e
[
P
]
Damper for blinds:
Width = 800 mm
Height = 1005 mm
Total pressure  = 1000 Pa
The total torque of about 5 Nm results from the diagram.
Determine your type of actuator from the table below:
If
Ζ
∴
1
SF
NmtorqueTotal
then use type
(with spring return)
′ 7 Nm GMA..1 (7Nm)
′ 14 Nm 2 x GMA..1 (2 x 7 Nm)
2
 or
′ 18 Nm GCA..1 (18 Nm)
3
′ 36 Nm 2 x GCA..1 (2 x 18 Nm)
4
1
 Safety Factor SF:
When calculating the number of actuators, remember to include non-definable
variables such as slight misalignment, damper age, etc. as a safety factor.
We recommend a total safety factor of 0.8.
Apply the same factor when calculating the actuator torque by the torque rating.
If the required actuator torque is greater than 7 Nm, the following can be used:
2
 Two actuators (tandem-mounted "powerpack") of type series GMA12..1, GMA32..1,
GMA13..1
3
 one actuator of type series GCA...1.
4
 If the actuator torque is greater than 18 Nm, two actuators of type series GCA...1 can
mechanically be connected and mounted on the damper shaft.
Sizing diagram
Example
Determining the actuator
type
Notes










