Siemens SINAMICS G120 - Motor Protection with Temperature Sensor

6.28 Motor protection with temperature sensor
The inverter can evaluate one of the following sensors to protect the motor against
overtemperature:
˽
702725
702725
702725
702725
702725
702725
● KTY84 sensor
● Temperature switch (e.g. bimetallic switch)
● PTC sensor
● Pt1000 sensor
KTY84 sensor
NOTICE
Overheating of the motor due to KTY sensor connected with the incorrect polarity
If a KTY sensor is connected with incorrect polarity, the motor can become damaged due to
overheating, as the inverter cannot detect a motor overtemperature condition.
● Connect the KTY sensor with the correct polarity.
Using a KTY sensor, the inverter monitors the motor temperature and the sensor itself for wire-
break or short-circuit:
● Temperature monitoring:
The inverter uses a KTY sensor to evaluate the motor temperature in the range from -48°
C ... +248° C.
Use the p0604 or p0605 parameter to set the temperature for the alarm and fault threshold.
– Overtemperature alarm (A07910):
- motor temperature > p0604 and p0610 = 0
– Overtemperature fault (F07011):
The inverter responds with a fault in the following cases:
- motor temperature > p0605
- motor temperature > p0604 and p0610 ≠ 0
● Sensor monitoring (A07015 or F07016):
– Wire-break:
The inverter interprets a resistance > 2120 Ω as a wire-break and outputs the alarm
A07015. After 100 milliseconds, the inverter changes to the fault state with F07016.
– Short-circuit:
The inverter interprets a resistance < 50 Ω as a short-circuit and outputs the alarm
A07015. After 100 milliseconds, the inverter changes to the fault state with F07016.
Temperature switch
The inverter interprets a resistance ≥ 100 Ω as being an opened temperature switch and
responds according to the setting for p0610.
Advanced commissioning
6.28 Motor protection with temperature sensor
Converter with the CU230P-2 Control Units
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE 325