HVAC400X – APPLICATION MANUAL
127
EN2B-0417GE51 R0719
If the motor thermal protection function detects that the temperature of the motor is too high, a motor
overtemperature fault occurs.
P3.9.7 MOTOR AMBIENT TEMPERATURE FACTOR (ID 705)
You can use this parameter to set the ambient temperature where the motor is installed.
The temperature value is given in degrees Celsius or Fahrenheit.
P3.9.8 MOTOR THERMAL ZERO SPEED COOLING (ID 706)
You can use this parameter to set the cooling factor at 0 speed in relation to the point where the motor operates at
nominal speed without external cooling.
When the speed is 0, this function calculates the cooling factor in relation to the point where the motor operates at
a nominal speed without external cooling.
The default value is set for conditions where there is no external fan. If you use an external fan, you can set the
value higher than without the fan, for example at 90%.
If you change parameter P3.1.1.4 (Motor Nominal Current), parameter P3.9.8 is automatically set to its default
value.
Although you change this parameter, it does not have an effect on the maximum output current of the drive. Only
parameter P3.1.1.7 Motor Current Limit can change the maximum output current.
The corner frequency for the thermal protection is 70% of the value of the parameter P3.1.1.2.
Fig. 28. The motor thermal current I
T
curve
Legend
A.
P
cooling
.
C.
Corner frequency.
B.
Overload area.
P3.9.9 MOTOR THERMAL TIME CONSTANT (ID 707)
You can use this parameter to set the motor thermal time constant.
The time constant is the time during which the calculated warming curve becomes 63% of its target value. The
length of the time constant is in relation with the dimension of the motor.
A
C
100%
ID706=40%
B
I
T
f
n
f
