Siemens SINUMERIK 840D sl Series Diagnostics Manual page 704

Overview of Alarms
Remedy: For closed-loop speed and torque control with speed encoder:
- check the speed signal (interrupted cable, polarity, pulse number).
If there is no fault, then the fault tolerance can be increased (p1744).
For closed-loop speed and torque control without speed encoder:
- check whether the drive stalls due to the load if the speed setpoint is still zero. If yes, then
increase the current setpoint using p1610.
- if the motor excitation (magnetizing) time (r0346) was significantly reduced, then it should
be increased again.
- check the current limits (p0640, r0067). If these are too low, then the drive cannot be
magnetized.
If there is no fault, then the fault tolerance (p1745) or the delay time (p2178) can be
increased.
207903 <location>Drive: Motor speed deviation
Reaction: NONE
Acknowledge: NONE
Cause: The absolute value of the speed difference from the two setpoints (p2151, p2154) 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.
- the speed controller is inhibited (refer to p0856; refer to Kp/Tn adaptation of the speed
controller).
- for closed-loop torque control, the speed setpoint does not track the speed actual value.
- for active Vdc controller.
The signal is not generated if the ramp-function generator tracking prevents the setpoint
and actual speed from drifting (moving) apart.
Only for vector drives:
For V/f control, the overload condition is detected as the Imax controller is active.
See also: p2149
Remedy: - increase p2163 and/or p2166.
- increase the torque/current/power limits.
- enable the speed controller.
- for closed-loop torque control: The speed setpoint should track the speed actual value.
207910 <location>Drive: Motor overtemperature
Reaction: NONE
Acknowledge: NONE
Cause: KTY:
The motor temperature has exceeded the alarm threshold (p00604).
VECTOR: The response parameterized in p0610 becomes active.
PTC:
The response threshold of 1650 Ohm was exceeded.
Alarm value (r2124, decimal):
1: No output current reduction.
2: Output current reduction active.
See also: p0604
Remedy: - check the motor load.
- check the motor ambient temperature.
207920 <location>Drive: Torque too low
Reaction: NONE
Acknowledge: NONE
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SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
© Siemens AG, 2005. All rights reserved
08/2005