Siemens SIMATIC ET 200pro Quick Manual page 145

10.3 Thermal motor model
Description
The approximate winding temperature of the motor is calculated electronically
using the measured motor currents and the device parameters 'rated operating
current' and 'tripping class'. This indicates, depending on the temperature,
whether the motor is overloaded or functioning in the normal operating range.
10.3.1 Device parameters
Response to overload – thermal motor model
(can only be parameterized for high feature motor starters)
This device parameter configures how the motor starter responds to an over-
load:
• 'Trip without restart'
• 'Trip with restart'
• 'Warning'
After overload, the switch-off command can only be reset after the motor
model has fallen below the switchback threshold and a subsequent reset
command (trip reset, DO 0.3) is issued.
Danger
Trip with restart means that with a pending switch-on command the motor
starter switches on automatically (autoreset) after the recovery time has
elapsed.
Caution
If the value of the thermal motor model exceeds the limit value of 178% for the
self-protection mechanism of the motor starter, the motor starter creates a
switch-off command itself independently of the parameterization "Response to
overload - thermal motor model".
SIMATIC – ET 200pro motor starter
GWA 4NEB 950 5661-02 DS 04
10-5