Firmware Manual

9000X AF Drives
8-64 For more information visit: www.eaton.com
MN04004001E
August 2010
Description of Parameters
Figure 8-48: Motor Temperature Calculation
707 Motor thermal protection:
Time constant
234567 (P1.7.11)
This time can be set between 1 and 200 minutes.
This is the thermal time constant of the motor, the larger the motor, the longer 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 the motor design and it varies between different
motor manufacturers.
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 based on it. As a rule of thumb, the motor thermal time constant
in minutes is equal 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. See Figure 8-48.
708 Motor thermal protection:
Motor duty cycle
234567 (P1.7.12)
Defines how much of the nominal motor load is applied.
The value can be set to 0% – 100%. See Page A-4.
709 Stall protection 234567 (P1.7.13)
0 No response
1 Warning
2 Fault, stop mode after fault according to ID506
3 Fault, stop mode after fault always by coasting
Setting the parameter to 0 will deactivate the protection and reset the stall time
counter. See Page A-4.
Time Constant T
*
Time
Fault/Warning
ID704
* Changes by motor size and
adjusted with ID707.
Motor Temperature
= (I/I
T
)
2
x (1-e
-t/T
)
Motor
Current
I/I
T
Trip Area
105%
Motor
Temperature
Θ