Switching Frequency Monitoring - Siemens SIRIUS 3RW55 Equipment Manual

Functions
8.8 Condition Monitoring
Parameters
Response to error 1)
Lower limit - error
Lower limit - maintenance de‐
manded
Response to error
1)
1) Generally valid parameter that can only be set in Parameter set 1.
8.8.4

Switching frequency monitoring

Operating principle
If motors are started frequently, this can cause the motor to overheat. The 3RW55 and 3RW55
Failsafe soft starters monitor the switching frequency in order to adhere to the waiting and
cooling times.
Application
• Prevention of process-related critical application states that occur as a result of too frequent
starting in conjunction with insufficient cooling time (Mode 1) or as a result of not observing
cooling times between 2 operating phases (Mode 2).
• For example, refrigeration compressors that have to remain switched off for a specific time
after reaching a maximum number of starts.
Setting via 3RW5 HMI High Feature
• Menu: "Parameters > Soft Starter > Parameter set 1 / 2 / 3 > Condition Monitoring > Switching
frequency monitoring"
• Access protection to the 3RW5 HMI High Feature is not active or has been reset.
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Description
Do not turn off (factory setting)
On exceeding the "Upper limit - error" the motor is not turned off.
Turn off
On exceeding the "Upper limit - error" the motor is turned off.
Lower limit
If the active power fails to reach this lower limit, an error is generated and the 3RW55 and
3RW55 Failsafe soft starters behave as set in the parameter "Response to error". The setting
"0%" deactivates the monitoring of the limit value.
• Factory setting: 0%
• Setting range: 0 ... 100%
• In steps of: 1%
If the active power fails to reach this lower limit, a warning is generated. The setting "0%"
deactivates the monitoring of the limit value.
• Factory setting: 0%
• Setting range: 0 ... 100%
• In steps of: 1%
Do not turn off (factory setting)
If the "Lower limit - error" is undershot, the motor is not turned off.
Turn off
If the "Lower limit - error" is undershot, the motor is turned off.
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006