I 2 T Monitoring - HEIDENHAIN iTNC 530 Service Manual

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2.2.8 I t monitoring
The instantaneous motor current is limited to either the maximum current of the power module,
or the maximum motor current, whichever is lower. The values result from the type of power
module and type of motor, and are saved in the motor or power module table.
In addition the I
The temperature rise of motor and power module is proportinal to the square of the current
consumed. Since heat removal may be non-uniformly during standstill or slow movement of the
motor, the monitoring distinguishes two different ranges. For this purpose the value F-AC
(crossover frequency to T-AC [Hz] has been added to the motor and power-module table.
Above this frequency the T-AC entry (Thermal time constant AC [s] applies; below this
frequency the T-DC entry Thermal time constant DC [s]) takes effect. The T-AC and T-DC input
values mark that point of the temperature curve at which 63 % of the maximum temperature
are reached. This defines a temperature model of motor or power module.
T [°C]
100 %
63 %
This temperature model serves to continuously calculate a mean current value. If the result
exceeds the nominal current (for motors MP2302.x is added) the I
(module 9160). In this case the PLC program should reduce the machining feed rate. If the
calculated mean current is higher than 1.1 times the nominal current (for motors MP2302.x
is added), an error message is generated; the drives are not switched off.
 MP2302.x contains a reference value for I
current of the motor (1 = rated current of the motor). If you enter zero, the I
the motor (not for the power supply unit) is switched off.
MP2302.x
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t monitoring for the power module and for the motor is executed individually.
T-AC
T-DC
Note
Never make any changes to the motor table!
Note
In the oscilloscope you can display the current values of the I
power module as well as the current utilization of the drive.
Reference value for I
Temperature curve via E-function
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t monitoring. The input value is a factor of the rated
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t monitoring
HEIDENHAIN Service Manual iTNC 530
t [s]
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-t monitoring responds
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t monitoring for
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-t monitoring of motor and