Breakdown Protection; No-Load Monitoring - Siemens SINAMICS G120 Operating Instructions Manual

Advanced commissioning
6.28 Monitoring the driven load
6.28.1

Breakdown protection

If the load of a standard induction motor exceeds the stall torque of the motor, the motor can
also stall during operation on the inverter. A stalled motor is stationary and does not develop
sufficient torque to accelerate the load.
If the "Motor model fault signal stall detection" r1746 for the time p2178 is present via the
"Motor model error threshold stall detection" p1745, the inverter signals "Motor stalled" and
fault F07902.
Parameter
r1408
p1745
r1746
p2178
r2198
6.28.2

No-load monitoring

In applications with fans, compressors or conveyor belts, an insufficient motor current indicates
that the power transmission from the motor to the load is interrupted.
If the motor current for the time p2180 lies below the current level p2179, the inverter signals
"output load not available" and alarm A07929.
Parameters
r0068
p2179
p2180
r2197
338
Description
Current controller status word
r1408.12 = 1: Motor stalled
Motor model fault threshold value stall detection (factory setting: 5%)
If the motor stalls too early with this setting, then using the trace function you have
the option of determining a better value. To do this, set p1745 = 100.
Motor model fault signal stall detection [%]
Motor stalled delay time (factory setting: 0.01 s)
Status word monitoring 2
r2198.07 = 1: Motor stalled
Description
Actual current value [A]
[0] = Unsmoothed
[1] = Smoothed with p0045
Output load detection current limit (Factory setting: 0 A)
p2179 = 0: No load detection deactivated
Output load detection delay time (factory setting: 2000 ms)
Status word, monitoring functions 1
r2197.11 = 1: Output load not available
Operating Instructions, 04/2018, FW V4.7 SP10, A5E31759476B AG
Converter with the CU250S-2 Control Units