Siemens SINUMERIK 808D ADVANCED Diagnostic Manual page 541

Fault
F7452: Following error too
high
Reaction: OFF1
Acknowledgement: IMMEDI‐
ATELY
F7801: Motor overcurrent
Reaction: OFF2
Acknowledgement: IMMEDI‐
ATELY
F7802: Infeed or power unit
not ready
Reaction: OFF2
Acknowledgement: IMMEDI‐
ATELY
F7815: Power unit has been
changed
Reaction: NONE
Acknowledgement: IMMEDI‐
ATELY
F7900: Motor blocked/speed
controller at its limit
Reaction: OFF2
Acknowledgement: IMMEDI‐
ATELY
Diagnostics Manual
Diagnostics Manual, 06/2015, 6FC5398-6DP10-0BA2
Cause
The difference between the position set‐
point position actual value (following error
dynamic model) is greater than the toler‐
ance.
● The drive torque or accelerating
capacity exceeded.
● Position measuring system fault.
● Position control sense incorrect.
● Mechanical system locked.
● Excessively high traversing velocity or
excessively high position reference
value (setpoint) differences.
The permissible motor limit current was ex‐
ceeded.
● Effective current limit set too low.
● Current controller not correctly set.
● Motor was braked with an excessively
high stall torque correction factor.
● Up ramp was set too short or the load
is too high.
● Short-circuit in the motor cable or
ground fault.
● Motor current does not match the
current of Motor Module.
After an internal power-on command, the
infeed or drive does not signal ready be‐
cause of one of the following reasons:
● Monitoring time is too short.
● DC link voltage is not present.
● Associated infeed or drive of the
signaling component is defective.
The code number of the actual power unit
does not match the saved number.
The servo motor has been operating at the
torque limit longer than 1s and below the
speed threshold of 120 rpm .
This signal can also be initiated if the speed
actual value is oscillating and the speed
controller output repeatedly goes to its limit.
SINAMICS V70 faults and alarms
7.2 Common faults and alarms
Remedy
Check the causes and resolve.
● Reduce the stall torque correction factor.
● Increase the up ramp or reduce the load.
● Check the motor and motor cables for short-
circuit and ground fault.
● Check the Motor Module and motor
combination.
● Ensure that there is a DC link voltage. Check
the DC link busbar. Enable the infeed.
● Replace the associated infeed or drive of the
signaling component.
Connect the original power unit and power up
the Control Unit again (POWER ON).
● Check whether the servo motor can rotate
freely or not.
● Check the torque limit.
● Check the inversion of the actual value.
● Check the motor encoder connection.
● Check the encoder pulse number.
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