8monitoring functions – Lenze i700 User Manual
Page 249
Lenze · i700 servo inverter · Reference manual · DMS 1.5 EN · 03/2014 · TD05
249
8
Monitoring functions
8.4
Monitoring of the motor utilisation (I²xt)
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UL 508 condition 2:
With a motor load of 110 % and a motor rotating field frequency of 10 Hz, the I²xt warning has to
be output faster than with a motor rotating field frequency of 20 Hz.
• The current motor rotating field frequency is displayed in the object
axis B).
• A motor load of 110 % occurs if the r.m.s. value of the total motor current displayed in the object
for axis B) corresponds to 1.1 times the rated motor current (
for axis B).
This condition can be met by the following parameter setting:
UL 508 condition 3:
After mains switching and a motor load > 100 %, the I²xt warning has to be output faster than in the
same load case before mains switching.
• A motor load of > 100 % occurs if the r.m.s. value of the total motor current displayed in the
object
(or
for axis B) is higher than the rated motor current (
for axis B).
This condition can be met by the following parameter setting:
Object
Name
Setting
Axis A
Axis B
I²xt: x1 = n01/nN (n01 ~ 0)
0 %
I²xt: y1 = i01/iN (x = n01 ~ 0)
< 100 %
I²xt: x2 = n02/nN (n02 = limit - reduced cooling)
Setting: 100 % * 20 Hz / rated motor frequency
or
I²xt: y2 = i02/iN (x = n02 = limit - reduced cooling)
≥ 100 %
Object
Name
Setting
Axis A
Axis B
Motor utilisation (I²xt): Starting value
> 0 %