8.24 Motor protection with temperature sensor
Overview
The converter can evaluate one of the following sensors to protect the motor against
overtemperature:
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702725
702725
702725
702725
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• 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
-48î™ Â°Cî™ ...î™ +248î™ Â°C.
Set the temperature for the alarm and fault thresholds with parameter p0604 or p0605.
– Overtemperature alarm (A07910):
-î™ motor temperatureî™ >î™ p0604 and p0610î™ =î™ 0
– Overtemperature fault (F07011):
The converter responds with a fault in the following cases:
-î™ î™ motor temperatureî™ > p0605
-î™ î™ motor temperatureî™ >î™ p0604 and p0610î™ > 0
• Sensor monitoring (A07015 or F07016):
– Wire-break:
The converter interprets a resistance >î™ 2120î™ Î© as a wire-break and outputs the alarm
A07015. After 100î™ milliseconds, the converter changes to the fault state with F07016.
– Short-circuit:
The converter interprets a resistance <î™ 50î™ Î© as a short-circuit and outputs the alarm
A07015. After 100î™ milliseconds, the converter changes to the fault state with F07016.
Advanced commissioning
8.24î™ Motor protection with temperature sensor
SINAMICS G120C Converters
340 Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK