Siemens SIRIUS 3RW55 - Intrinsic Device Protection; Intrinsic Device Protection (Page 171)

Parameters Description
Temperature sensor
1)
Sensor type
• Deactivated (factory setting)
The motor protection function is deactivated.
• Thermoclick
This sensor type is a temperature-dependent switch.
• PTC type A
This sensor type is a temperature-dependent resistor.
Response to overload temper‐
ature sensor
If the temperature sensor detects an overload on the motor, this is
signaled to the 3RW55 or 3RW55 Failsafe soft starter. You can set the
response to this:
• Turn o󹪜 without restart (factory setting)
On an overtemperature, an error is generated and the motor is
shut down. After the motor has cooled down, the error and the
trip can be acknowledged with the "Reset" function.
• Turn o󹪜 with restart
On an overtemperature, an error is generated and the motor is
shut down. After the motor has cooled down, the error and the
motor trip are automatically canceled.
• Warn
On an overtemperature, only a warning is output. After the mo‐
tor has cooled down, the warning is canceled automatically.
1)
Generally valid parameter that can only be set in Parameter set 1.
8.4 Intrinsic device protection
Operating principle
The 3RW55 and 3RW55 Failsafe soft starters have integrated intrinsic device protection (power
semiconductors and bypasses) that prevents inadmissible thermal overloading of the switching
elements.
In order to protect the bypasses and power semiconductors, the startup and maximum
operational currents of the motor are limited and the temperature monitored if current
measurement is available. The intrinsic device protection does not protect from short-circuit
stress.
The current switching element heating can be displayed via the measured value "Switching
element heating" (Page 227)
Acknowledgment after cooling time has elapsed.
If the 3RW55 or 3RW55 Failsafe soft starter is switched o󹪜 via a motor protection or intrinsic
device protection tripping operation, the action cannot be acknowledged using the "Reset"
(Page 173) function until the cooling time of the switching element has expired. The remaining
cooling time can be displayed via the measured value "Remaining switching element cooling
time" (Page 227).
Functions
8.4 Intrinsic device protection
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006 171