Siemens SIMOTICS T-1FW6 Configuration Manual page 99

Short-time duty S2
For short-time duty S2 the load duration is so short that the final thermal state is not reached.
The subsequent zero-current break is so long that the motor practically cools down completely.
NOTICE
Motor overload
An excessively high load can lead to shutdown, or if the temperature sensors are not correctly
evaluated, then the motor could be destroyed.
• Ensure that the load does not exceed the value I
• Ensure that the temperature sensors are correctly connected and evaluated.
The motor may only be operated for a limited time t < t
time t
with ν = (I
The thermal time constants, the maximum currents and the rated currents of the motors can
be taken from the data sheets.
The above equation is valid under the precondition that the initial temperature of the motor -
the intake temperature of the water cooling T
sheet.
Example
A motor should be operated with maximum current from the cold state.
• I
• t
The motor can be operated for a maximum of 66 s at maximum current.
1FW6 Built-in torque motors
Configuration Manual, 09/2022, A5E52220645B AA
can be calculated using the following logarithmic formula:
MAX
/ I ) 2 and thermal time constants t
M N
= 47 A, I = 26 A; this results in ν = 3.268
MAX N
= 180 s
TH
6.2 Configuring workflow
specified in the data sheets!
MAX
with a current I
MAX
.
TH
corresponds to what is specified in the data
VORL
Configuration
< I ≤ I . The
N M MAX
97