Lenze i700 - Manual (Page 245)

Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
245
8 Monitoring functions
8.4 Monitoring of the motor utilisation (I²xt)
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Speed-dependent evaluation of the motor current
By selecting a characteristic, the permissible motor current is evaluated depending on speed for
calculating the thermal motor utilisation. For this purpose, up to four operating points on the S1
characteristic of a motor can be used.
• The S1 characteristic can be found in the technical data sheet/catalogue of the respective
motor.
• The representation in the objects /characteristic is carried out as relative values with reference
to rated values.
0x2D4D | 0x354D - Motor utilisation (I²xt): User-definable characteristic
An example of how to enter the characteristic can be found in the following subchapter.

Note!
When you select a Lenze motor from the catalogue and transfer its parameters into the
controller, a typical characteristic is automatically set for the selected motor. A deviating
parameterisation is only required if the motor is operated in ambient conditions which
demand a general derating. Example: Use in site altitudes > 1000 m.
In case of motors of other manufacturers, the operating points have to be parameterised
based on the data sheet information.
Operating points
 Standstill n01-I01 For motors, this operating point is often described with
the no-Io values.
 Reference point n02-I02 If the value falls below the speed n02, a derating in the
current is required because:
• the motor cooling of self-ventilated motors
deteriorates considerably.
• a DC current load causes an increased power loss in a
winding.
For motors, this operating point is also described with
the no*-Io* values.
 Rated point (n03=nrated)-(I03=Irated) Rated values of the motor are the reference for all
operating points of the i²xt monitoring.
 Field weakening n04-I04 This operating point should be parameterised
independently of the use in the current application.
Sub. Name Lenze setting Data type
1 I²xt: x1 = n01/nN (n01 ~ 0) 0 % UNSIGNED_16
2 I²xt: y1 = i01/iN (x = n01 ~ 0) 100 % UNSIGNED_16
3 I²xt: x2 = n02/nN (n02 = limit - reduced cooling) 0 % UNSIGNED_16
4 I²xt: y2 = i02/iN (x = n02 = limit - reduced
cooling)
100 % UNSIGNED_16
5 I²xt: x3 = n03/nN (n03 = rated speed) 100 % UNSIGNED_16
6 I²xt: y3 = i03/iN (x = n03 = rated speed) 100 % UNSIGNED_16
7 I²xt: x4 = n04/nN (n04 = limit - field weakening) 100 % UNSIGNED_16
8 I²xt: y4 = i04/iN (x = n04 = limit - field
weakening)
100 % UNSIGNED_16
 Write access  CINH  OSC  P  RX  TX