KTY temperature sensor, polarity is to be considered, KTY 83-110

Question:
Why does the polarity has to be considered when a continuous temperature sensor (KTY) is connected?

Answer:
Continuous temperature sensors (KTY) have two connections, a positive and a negative one and correspondingly two connection cables.
In case of incorrect polarity the resistance measurement would not be executed correctly. Consequently, a motor temperature would be detected and displayed smaller than the actual one.

Consequences:
The drive controller's monitoring function for the motor temperature would not be able to protect the motor from overheating.
When the system is running the motor model of the motor control would be affected unfavourably due to the incorrectly detected motor temperature.

Sensor KTY 83-110:
When the polarity is mixed the KTY 83-110 works up to 120 °C. When temperatures are > 120 °C the measured temperature value remains constant, this means that the temperature monitoring does not work in case of > 120 °C.
The KTY sensors used by Lenze have been specified up to a temperature of 175 °C. Therefore, the KTY temperature sensors will not be damaged even if the motor is operated close to the switch-off temperature of the temperature monitoring of 150 °C.

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/200700609/1/