Commissioning
5–18
1070 066 028-101 (01.05) GB
5.1.13
Stalling warning
The stalling warning serves to recognize the danger of overload on an
asynchronous motor. Before the motor is electrically stalled and stops, the
frequency inverter outputs the“
I
limit
” 24 V signal at X13.3 as a stalling
warning.
By evaluating this signal, the motor can be operated up to the critical output
frequency f
limit
. f
limit
is in the field-weakening range, above this frequency,
the motor cannot be overloaded, and useful operation is no longer possible.
For the stalling warning, a maximum admissible current limit below the
module peak current is determined. This limit curve is designed to emulate
the motor characteristic. It can be determined, e.g., by measuring the motor
at different speeds on a test bench.
f
mot
[Hz]
f
trans
P34
f
max
P02
I
2max
I
1max
I
max module
a) Asynchronous motors
with field weakening
f
mot
[Hz]
f
trans
= f
max
P34 = P02
I
2max
= 0
I
1max
I
max module
b) Asynchronous motors
without field weakening
| I | [A]
| I | [A]
P33 (A-0-0033)
Activate stalling warning
factory
setting
all
DMs, DS
UE0
(0)
UE1
(1)
off
on
P34 (A-0-0034)
f
trans
transition frequency
Starting point of the speed-dependent decrease of the current limit.
The optimum value is determined by the specific application. The rated
frequency entered via P07 can be selected as an approximate value:
0.0
999 Hz
smallest step
Range [Hz]
factory
setting
all
DMs, DS
50
0.1
1
100
min.
max.