Danfoss FC 300 Design Manual page 143

FC 300 Design Guide
1-9* Motor Temperature
Parameters for setting the temperature protection
features for the motor.
1-90 Motor Thermal Protection
Value:
No protection
Thermistor warning
Thermistor trip
ETR warning 1
ETR trip 1
ETR warning 2
ETR trip 2
ETR warning 3
ETR trip 3
ETR warning 4
ETR trip 4
Function:
The frequency converter determines the motor
temperature for motor protection in two different
ways:
• Via a thermistor sensor connected to one
of the analog or digital inputs (par. 1-93
Thermistor Source).
• Via calculation (ETR = Electronic Terminal
Relay) of the thermal load, based on the
actual load and time. The calculated ther-
mal load is compared with the rated motor
current I and the rated motor frequen-
M,N
cy f . The calculations estimate the need
M,N
for a lower load at lower speed due to less
cooling from the fan incorporated in the
motor.
Select No protection [0] for a continuously over-
loaded motor, when no warning or trip of drive is
required.
Select Thermistor warning [1] to activate a warn-
ing when the connected thermistor in the motor
reacts in the event of motor over-temperature.
Select Thermistor trip [2] to stop (trip) the fre-
quency converter when the connected thermistor
in the motor reacts in the event of motor over-
temperature.
The thermistor cut-out value is > 3 kΩ.
Integrate a thermistor (PTC sensor) in the motor
for winding protection.
factory setting
How to Programme
[0]
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
() display text []
MG.33.B7.02 - VLT is a registered Danfoss trademark
Motor protection can be implemented using a
range of techniques: PTC sensor in motor wind-
ings; mechanical thermal switch (Klixon type); or
Electronic Thermal Relay (ETR).
See parameter group 1-9* Motor Temperature.
Using a digital input and 24 V as power supply:
Example: The frequency converter trips when the
motor temperature is too high Parameter set-up:
Set Par. 1-90 Motor Thermal Protection to Ther-
mistor Trip [2]
Set Par. 1-93 Thermistor Source to Digital Input
[6]
Using a digital input and 10 V as power supply:
Example: The frequency converter trips when the
motor temperature is too high.
Parameter set-up:
Set Par. 1-90 Motor Thermal Protection to Ther-
mistor Trip [2]
Set Par. 1-93 Thermistor Source to Digital Input
[6]
value for use in communication via serial communication port
143