Integrate a thermistor (PTC sensor) in the motor for winding
protection.
Motor protection can be implemented using a range of techni-
ques: PTC sensor in motor windings; mechanical thermal switch
(Klixon type); or Electronic Thermal Relay (ETR).
Using a digital input and 24 V as power supply:
Example: The frequency converter trips when the motor tem-
perature is too high.
Parameter set-up:
Set Par. 1-90
Motor Thermal Protection
to
Thermistor Trip
[2]
Set Par. 1-93
Thermistor Source
to
Digital Input 33
[6]
Using a digital input and 10 V as power supply:
Example: The frequency converter trips when the motor tem-
perature is too high.
Parameter set-up:
Set Par. 1-90
Motor Thermal Protection
to
Thermistor Trip
[2]
Set Par. 1-93
Thermistor Source
to
Digital Input 33
[6]
Using an analog input and 10 V as power supply:
Example: The frequency converter trips when the motor tem-
perature is too high.
Parameter set-up:
Set Par. 1-90
Motor Thermal Protection
to
Thermistor Trip
[2]
Set Par. 1-93
Thermistor Source
to
Analog Input 54
[2]
Do not select a reference source.
VLT
®
HVAC Drive Instruction Manual
6. How to program the adjustable frequency
drive
MG.11.A4.22 - VLT
®
is a registered Danfoss trademark
79
6