Lenze i700 - Manual (Page 242)

8 Monitoring functions
8.4 Monitoring of the motor utilisation (I²xt)
242
Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
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0x2D50 | 0x3550 - motor utilisation (I²xt): Motor overload error
The introduction of a two-component model with two time constants (one for the winding and the
housing/laminated core, respectively) serves to display the thermal behaviour of the motors up to
500% of the rated current.
From version 01.04 onwards
If the disconnection must not or cannot be executed by a higher-level Controller, the operation can be interrupted
by the following parameter setting:
• As a response to the excess of the adjustable error threshold, set "1: Fault" in subindex 1.
• In subindex 2, set the threshold value as error threshold which in case of being exceeded triggers an interruption
of the operation.
Sub. Name Lenze setting Data type
 1 Motor utilisation (I²xt): Response 0: No Response UNSIGNED_8
 2 Motor utilisation (I²xt): Error threshold 105 % UNSIGNED_16
Subindex 1: Motor utilisation (I²xt): Response
Selection list (Lenze setting printed in bold)
0 No response
1 Fault
 Write access  CINH  OSC  P  RX  TX UNSIGNED_8
Subindex 2: Motor utilisation (I²xt): Error threshold
Setting range (min. value | unit | max. value) Lenze setting
0 % 250 105 %
 Write access  CINH  OSC  P  RX  TX UNSIGNED_16
Structure of the I 2 xt monitoring
 Thermal utilisation of the motor in [%]
Axis A Axis B Symbol Description Dimension unit
- - I
act motor
Actual motor current A
- - I
perm motor
Permissible motor current (speed-dependent) A
0x2D4C:1 0x354C:1 τ
1
Therm. time constant coil s
0x2D4C:2 0x354C:2 τ
2
Therm. time constant of the laminated core s
0x2D4C:3 0x354C:3 k
1
Percentage of the winding in the final temperature %
- - k
2
Percentage of the laminated core in the final temperature:
k
2
= 100 % - k
1
%
k
1
1
(1 + p )
t
1
k
2
1
(1 + p )
t
2
Œ
I
act motor
I
perm motor
(n)
2