Description of the Software Modules and Parameters
Parameter manual
b maXX
BM3000
Document no.: 5.12001.07
735
4
Figure 229:
Function example of the motor l
2
t overload monitoring
4.11.5.2 Speed variable l
2
t overload monitoring
The preset standard solution referring to the constant maximum continuous current
throughout the total speed range is inadequate to many applications with synchronous
and asynchronous machines. Therefore, in the following implementation solutions are in-
troduced considering the speed-dependence of the maximum continuous current of the
l
2
t motor model.
Speed variable I2t overload monitoring of synchronous machines
As long as error is acknowledged in controlword 108.1
Motor error
error no. 99
Motor I2t time constant (107.28) = 600 s
Motor
I2t actual value
6.28
Motor I2t actual value:
After error shut-down
from drive manager
Motor I2t actual value
(theoretically: w/o error shut-down)
Motor warning
Warnung no. 34
act
Limit
App
arent
current
actual
value
6.30
I
'
=
=
8 A
5,1 A
*
*
(
(
)
)
2
2
2
2
I
*
I
I
I
I
2,46
N
'
'
'
act
act
act
t
t
t
0
246 %
100 %
80 %
6.39
( 8 A)
5000_0357_rev01.cdr
100 %
6.30
NOTE!
If you have to consider UL 508 C:
If motor temperature is not monitored by a motor temperature sensor, motor overload
monitoring is to be activated. Among other things nominal current
and time
constant
