ABB ACSM1 Firmware Manual page 42

42
Temperature sensors
It is possible to detect motor overtemperature by connecting a motor temperature
sensor to thermistor input TH of the drive or to optional encoder interface module
FEN-xx.
Constant current is fed through the sensor. The resistance of the sensor increases
as the motor temperature rises over the sensor reference temperature T
the voltage over the resistor. The temperature measurement function reads the
voltage and converts it into ohms.
The figure below shows typical PTC sensor resistance values as a function of the
motor operating temperature.
Temperature
Normal
Excessive
The figure below shows typical KTY84 sensor resistance values as a function of the
motor operating temperature.
KTY84 scaling
90 °C = 936 ohm
110 °C = 1063 ohm
130 °C = 1197 ohm
150 °C = 1340 ohm
It is possible to adjust the motor temperature supervision limits and select how the
drive reacts when overtemperature is detected.
WARNING! As the thermistor input on the JCU Control Unit is not insulated
according to IEC 60664, the connection of the motor temperature sensor requires
double or reinforced insulation between motor live parts and the sensor. If the
assembly does not fulfil the requirement,
- the I/O board terminals must be protected against contact and must not be
Drive control and features
Ohm
4000
1330
PTC resistance
550
0...1.5 kohm
> 4 kohm
100
ohm
3000
2000
1000
0
-100
T
0 100 200 300
, as does
ref
T (°C)