Siemens CU240B-2 Parameter Manual page 700

Faults and Alarms
List of Faults and Alarms
F07901 Drive: Motor overspeed
Reaction: OFF2 (IASC/DCBRAKE)
Acknowledge: IMMEDIATELY
Cause: The maximum permissible speed was either positively or negatively exceeded.
The maximum permissible positive speed is formed as follows: Minimum (p1082, CI: p1085) + p2162
The maximum permissible negative speed is formed as follows: Maximum (-p1082, CI: 1088) - p2162
Remedy: The following applies for a positive direction of rotation:
- check r1084 and if required, correct p1082, CI:p1085 and p2162.
The following applies for a negative direction of rotation:
- check r1087 and if required, correct p1082, CI:p1088 and p2162.
Activate pre-control of the speed limiting controller (p1401.7 = 1).
Increase the hysteresis for the overspeed signal p2162. This upper limit is dependent upon the maximum motor
speed p0322 and the maximum speed p1082 of the setpoint channel.
F07902 (N, A) Drive: Motor stalled
Reaction: OFF2 (IASC/DCBRAKE, NONE, OFF1, OFF3, STOP2)
Acknowledge: IMMEDIATELY
Cause: For a vector drive the system has identified that the motor has stall for a time longer than is set in p2178.
Fault value (r0949, decimal interpretation):
1: Reserved.
2: Stall detection using r1408.12 (p1745).
See also: p2178 (Motor stalled delay time)
Remedy: Steps should always be taken to ensure that both motor data identification and the rotating measurement were
carried out (see p1900, r3925).
- check whether the drive stalls solely due to the load in controlled mode or when the speed setpoint is still zero. If
yes, then increase the current setpoint using p1610.
- if the motor excitation time (p0346) was significantly reduced and the drive stalls when it is switched on and run
immediately, p0346 should be increased again.
- check the current limits (p0640, r0067, r0289). If the current limits are too low, then the drive cannot be magnetized.
- check whether a line phase failure is affecting power unit PM230, PM250, PM260.
- check whether the motor cables are disconnected (see A07929).
If there is no fault, then the fault tolerance (p1745) or the delay time (p2178) can be increased.
A07903 Drive: Motor speed deviation
Reaction: NONE
Acknowledge: NONE
Cause: The absolute value of the speed difference from the setpoint (p2151) and the speed actual value (r2169) exceeds
the tolerance threshold (p2163) longer than tolerated (p2164, p2166).
The alarm is only enabled for p2149.0 = 1.
Possible causes could be:
- the load torque is greater than the torque setpoint.
- when accelerating, the torque/current/power limit is reached. If the limits are not sufficient, then it is possible that
the drive has been dimensioned too small.
- for closed-loop torque control, the speed setpoint does not track the speed actual value.
- for active Vdc controller.
For U/f control, the overload condition is detected as the Imax controller is active.
See also: p2149 (Monitoring configuration)
Remedy: - increase p2163 and/or p2166.
- increase the torque/current/power limits.
- for closed-loop torque control: The speed setpoint should track the speed actual value.
- de-activate alarm with p2149.0 = 0.
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SINAMICS G120 / Control Units CU240B/E-2 Parameter Manual (LH11), 01/2011
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