Firmware 03.00 - DMS EN 5.0 - 07/2009
L
109
8400 BaseLine D | Software Manual
Motor control (MCTRL)
Monitoring functions
Adjustment
Calculate the overload threshold I
2
xt:
If you reduce
starting from the calculated value, the motor utilisation meter I
2
xt
(
) will already be counted up before the rated overload threshold has been
reached.
starting from the calculated value, the motor utilisation meter I
2
xt
(
) will be counted up after the rated overload threshold has been reached.
The motor utilisation meter starts to count up when the apparent motor current (
higher than the rated motor current (
).
[5-7]
Tripping characteristic of I
2
xt monitoring
Example:
= I
r
/I
N
x 100 %
–
= 1.5 x rated motor current
has reached the final value 100 % at output
frequencies f > 40 Hz. The controller switches off with the error "Thermal motor
overload, I
2
is set to "0" (trip).
• I
r
• I
N
Rated motor current (
Rated current of the controller at a switching
frequency of f = 8 kHz
f: output frequency
t: release time
I
N
: Rated controller current at a switching frequency of f = 8 kHz
I
r
: rated motor current (
: Apparent motor current
C00120
I
r
I
N
-----
100%
⋅
=
60
180
240
300
360
t [s]
0.5
0
0
1.0
1.5
2.0
C00054
I
r
120
f = 0 Hz
f = 20 Hz
f > 40 Hz
I x 100 %
I
r
N
C00120 <
I x 100 %
I
r
N
C00120 =
I x 100 %
I
r
N
C00120 >