Siemens TV Converter Box 611 User Manual
Configuring the motor
5.3 Short-time duty S2 and intermittent duty S3
1FW6 Built-in torque motors
Configuration Manual, 05/2009, 6SN1197-0AD00-0BP7
Configuration Manual, 05/2009, 6SN1197-0AD00-0BP7
79
Intermittent duty S3
With intermittent duty S3, periods of load time Δt
B
with constant current alternate with
periods of downtime Δt
S
with no current feed. The motor heats up during the load time and
then cools down again while at standstill. After a sufficient number of duty cycles with cycle
duration Δt
Spiel
= Δt
B
+ Δt
S
, the temperature characteristic oscillates between a constant
maximum value T
o
and a constant minimum value T
u
; see figure below.
7LPHW
7LPHW
7HPSHUDWXUH7
&XUUHQW,
ෙW
%
ෙW
6
ෙW
6SLHO
7
X
7
R
ื7
1
,
0
,
0$;
Figure 5-9
Current and temperature characteristic for intermittent duty S3
For currents I
N
< I
M
≤ I
MAX
, the rms continuous current may not exceed the rated current:
,
HII
˂W
6SLHO
,
0
y˂W
%
,
0
˂W
%
˂W
6SLHO
,
1
In this respect, the cycle duration should not exceed 10% of the thermal time constant t
TH
. If
a longer cycle duration is necessary, please contact your local Siemens office.
Example
When the thermal time constant t
TH
= 180 s, this results in the following maximum
permissible cycle duration:
t
t
Spiel
= 0.1 · 180 s = 18 s