Thermal Motor Models - Siemens SINAMICS S150 NEMA Operating Instructions Manual

Sensor monitoring for wire breakage/short-circuit
● A sensor monitoring function for a short-circuit in the sensor cable is possible for a PTC
and a PT1000 or KTY84 sensor. For a PT1000 or KTY84 sensor, it is possible to monitor
for wire breakage:
If the temperature of the motor temperature monitoring is outside the designated range of
-220 °F (-140 °C) to +482 °F (+250 °C), this means that the sensor cable is either broken
or has a short-circuit. Alarm A07015 ("Motor temperature sensor alarm") is output. Fault
F07016 ("Drive: Motor temperature sensor fault") is triggered once the waiting time
defined in p0607 has elapsed.
● Fault F07016 can be suppressed using p0607 = 0. If an induction motor is connected, the
drive continues operating with the data calculated in the thermal motor model.
● If the system detects that the motor temperature sensor set in p0600 is not connected,
alarm A07820 "Temperature sensor not connected" is triggered.
9.5.5.6

Thermal motor models

Thermal motor models are used so that thermal motor protection is guaranteed even without
a temperature sensor or with a deactivated temperature sensor (p0600 = 0).
The simultaneous use of temperature sensors and a thermal motor model also makes
sense. For example, a very fast temperature increase that is not detected by the sensors in
sufficient time can potentially damage a motor. This situation can occur for motors with a low
thermal capacity.
Depending on the particular model, the temperature rise is either assigned different motor
parts (stator, rotor), or is calculated from the motor current and the thermal time constant.
A combination of motor temperature model with additional temperature sensors can also be
deployed.
NOTICE
Material damage caused by overheating for motor operation without sensor
A thermal motor model cannot fully replace a sensor. The thermal model cannot protect the
motor if incorrectly installed, for increased ambient temperatures or if errors were made in
the parameter settings. Without temperature sensors, thermal motor models are not in a
position to identify or take into account the ambient temperatures or the initial motor
temperature. This can cause motor overheating and so material damage.
• Do not deploy thermal motor models when a higher environment temperature or a
Enclosed Drives
Operating Instructions, 12/2018, A5E36652151A
higher initial temperature of the motor can occur.
Functions, monitoring and protective functions
9.5 Monitoring functions and protective functions
705