Siemens SIRIUS 3RW55 - Switching Frequency Monitoring

Functions
7.7 Condition Monitoring
SIRIUS 3RW55 soft starter
122 Manual, 08/2018, A5E35630887002A/RS-AB/002
7.7.4
Switching frequency monitoring
Operating principle
If motors are started frequently, this can cause the motor to overheat. The soft starter
monitors the switching frequency in order to adhere to the wait and cooling down times.
Application
● Prevention of a critical motor temperature rise due to too frequent starting in conjunction
with too short a cooling time of the motor (Mode 1).
● Prevention of a critical application temperature rise, if cooling times between 2 operating
phases have not been adhered to (Mode 2).
Switching frequency monitoring - Mode 1
n
Maximum number of starts
t
1
Switching frequency monitoring time t
1
t
2
Switching frequency monitoring time t
2
Switching frequency monitoring - Mode 2
n
Maximum number of starts
t
1
Switching frequency monitoring time t
1
t
2
Switching frequency monitoring time t
2