ABB ACS880 Firmware Manual page 62

62 Program features
• sensors installed in the windings. This will result in a more accurate motor model.
Motor thermal protection model
The drive calculates the temperature of the motor on the basis of the following
assumptions:
1. When power is applied to the drive for the first time, the motor is assumed to be at
ambient temperature (defined by parameter
After this, when power is applied to the drive, the motor is assumed to be at the
estimated temperature.
2. Motor temperature is calculated using the user-adjustable motor thermal time and
motor load curve. The load curve should be adjusted in case the ambient
temperature exceeds 30 °C.
Note: The motor thermal model can be used when only one motor is connected to
the inverter.
Temperature monitoring using PTC sensors
One PTC sensor can be connected to digital input DI6. FEN-xx encoder interfaces
(optional) also have a connection for one PTC sensor.
+24VD
T
DI6
The resistance of the PTC sensor increases when its temperature rises. The
increasing resistance of the sensor decreases the voltage at the input, and eventually
its state switches from 1 to 0, indicating overtemperature.
35.50 Motor ambient temperature).