Thermal motor protection

Thermal motor protection avoids overheating and, therefore, prevents irreparable damage to the motor. For this purpose, temperature sensors detect the winding temperature. As standard, the inverters can evaluate the following temperature sensors.

Note that the KY/KTY, PK, and PI temperature sensors cannot be connected in series by several motors. For further information, refer to chapter Group drive and multi-motor drive.

Motor protection

Number of sensors
in the motor

SEW-EURODRIVE
designation

PTC thermistor

3

TF

Bimetallic temperature switch

3

TH

Semiconductor temperature probe KTY84-130

1

KY/KTY

Pt1000 platinum temperature probe,
mounted in winding

1

PK

Pt1000 platinum temperature probe,
mounted in stator housing

1

PI

Motor series

Temperature sensor

Motor protection

CM..

KTY84-130, Pt1000

Comprehensive protectionComprehensive protection, as a thermal model protects the winding in addition to the measured value.

CM..

TF

Limited protectionDepending on the motor size.

DR..

TF, TH

Comprehensive protectionComprehensive protection due to one sensor per motor phase.

DR..

KTY84-130

Limited protectionIf the temperature measured by the temperature probe exceeds the limit temperature of the set thermal class of the motor, the inverter issues a fault message. There is no evaluation of the motor model. Thermal overload of windings is possible since the sensor is only installed in one winding.

DR..

Pt1000 (PK)

Limited protectionIf the temperature measured by the temperature probe exceeds the limit temperature of the set thermal class of the motor, the inverter issues a fault message. There is no evaluation of the motor model. Thermal overload of windings is possible since the sensor is only installed in one winding.

DR..

Pt1000 (PI)

Comprehensive protectionComprehensive protection, as a thermal model protects the winding in addition to the measured value.

Third-party motors

PTC thermistor,
bimetallic temperature switch

Comprehensive protectionComprehensive protection due to one sensor per motor phase.

Third-party motors

KTY84-130, Pt1000

Limited protectionIf the temperature measured by the temperature probe exceeds the limit temperature of the set thermal class of the motor, the inverter issues a fault message. There is no evaluation of the motor model. Thermal overload of windings is possible since the sensor is only installed in one winding.

For additional information on the thermal motor protection, refer to the documentation of the motors.