Firmware Manual

Appendix A—Description of Parameters
PowerXL DG1 Series Adjustable Frequency Drives MN040004EN—March 2014 www.eaton.com 163
P9.10 312 Motor Thermal Time 1, 2, 3, 4 RW
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 2 x t6. 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 59.
Figure 59. Motor Temperature Calculation
P9.11 313 Stall Protection 1, 2, 3, 4 RW
Stall protection is a type of overcurrent protection. It protects the motor from short
time overload situations like a stalled shaft. This is customer selectable based off of
current level, frequency level and time.
0 No Action
1 Warning
2 Fault
3 Fault, Coast
Code Modbus ID Parameter Application
RO/RW
Time Constant T
*
Time
Fault/Warning
P9.8
* Changes by motor size and adjusted with P9.10.
Motor Temperature
= (I/I
T
)
2
x (1-e
-t/T
)
Motor
Current
I/I
T
Trip Area
105%
Motor
Temperature
Θ