8.24 Motor protection with temperature sensor
Overview
The converter can evaluate one of the following sensors to protect the motor against
overtemperature:
˽
702725
702725
702725
702725
702725
702725
• KTY84 sensor
• Temperature switch (e.g. bimetallic switch)
• PTC sensor
• Pt1000 sensor
Function description
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 be damaged by overheating,
as the converter cannot detect a motor overtemperature condition.
• Connect the KTY sensor with the correct polarity.
Using a KTY sensor, the converter monitors the motor temperature and the sensor itself for
wire-break or short-circuit:
• Temperature monitoring:
The converter uses a KTY sensor to evaluate the motor temperature in the range from
-48°C...+248°C.
Set the temperature for the alarm and fault thresholds with parameter p0604 or p0605.
– Overtemperature alarm (A07910):
-motor temperature>p0604 and p0610=0
– Overtemperature fault (F07011):
The converter 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 converter interprets a resistance >2120Ω as a wire-break and outputs the alarm
A07015. After 100milliseconds, the converter changes to the fault state with F07016.
– Short-circuit:
The converter interprets a resistance <50Ω as a short-circuit and outputs the alarm
A07015. After 100milliseconds, the converter changes to the fault state with F07016.
Advanced commissioning
8.24Motor protection with temperature sensor
SINAMICS G120C Converters
340 Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK