User`s manual

apfiff09 marine vacon • 201
24-
6
Freq. Out
Motor Nominal Freq.
100 %
Zero
cooling
Factor
70 % of Fn
Cooling Factor
P2.12.5.5 Motor thermal protection: Time constant ID707
This time can be set between 1 and 200 minutes.
This is the thermal time constant of the motor. The bigger the motor, the bigger the time
constant. The time constant is the time within which the calculated thermal stage has
reached 63% of its final value.
The motor thermal time is specific to motor design and it varies between different motor
manufacturers. The default value changes between unit sizes.
If the motor's t6 time (t6 is the time in seconds the motor can safely operate at six times
the rated current) is known (given by the motor manufacturer) the time constant
parameter can be set basing on it. As a rule of thumb, the motor thermal time constant
in minutes equals to 2xt6. If the drive is in stop stage the time constant is internally
increased to three times the set parameter value. The cooling in the stop stage is based
on convection and the time constant is increased.
P2.12.5.5 Motor thermal protection: Motor duty cycle ID708
Setting value to 130 % motor calculated temperature will reach nominal temperature
with 130 % of motor nominal current.