Table of Contents
Advertisement
Figure 4-1
High short-term overload conditions require additional protective measures as a result of
the thermal coupling time of the temperature sensor.
Note
Temperature evaluation using only a Pt1000 does not guarantee full motor protection.
NOTICE
Destruction of the motor for a thermal critical load
A thermally critical load, e.g. high overload when the motor is stationary, can destroy
the motor.
• Employ additional protective measures, e.g. an overcurrent relay.
4.1.1.2
Temperature evaluation using the PTC thermistor triplet (full motor protection)
For special applications (e.g. when a load is applied with the motor stationary or for
extremely low speeds), the temperature of all of the three motor phases must be
additionally monitored using a PTC thermistor triplet.
Note
If water-cooled synchronous built-in motors are operated for longer than one minute in
standstill with the standstill torque, a phase can be thermally loaded overproportionately.
• Reduce the permanent standstill torque by up to 20 %.
• Protect the winding thermally with a thermistor triplet (PTC) with an external tripping
unit.
The PTC thermistor triplet can be evaluated using an external tripping unit (this is not
included in the scope of delivery). This means that the sensor cable is monitored for wire
breakage and short-circuit by this unit.
SIMOTICS M-1FE1 synchronous built-in motors
Configuration Manual, 09/2019, A5E47872980B AA
Pt1000 characteristic
Motor components, characteristics and options
4.1 Motor components
53
Advertisement
Table of Contents
