1.7.3 Trouble Shooting
The following table is to be seen as a "First Aid" box. There can be a large number of different
reasons for a fault, depending on the particular conditions in your system. The fault causes
described below are mostly those which directly influence the motor. Peculiarities which
show up in the control loop behaviour can usually be traced back to an error in the para-
meterization of the servo amplifier. The documentation for the servo amplifier and the setup
software provides information on these matters.
For multi-axis systems there may be further hidden reasons for faults.
Fault
Motor doesn't
rotate
Motor runs away — Motor phases in wrong sequence
Motor oscillates — Break in the shielding of the resolver
Error message:
brake
Error message:
output stage
fault
Error message:
resolver
Error message:
motor tem-
perature
Brake does not
grip
Possible cause
— Servoamplifier not enabled
— Break in setpoint lead
— Motor phases in wrong sequence
— Brake not released
— Drive is mechanically blocked
cable
— amplifier gain to high
— Short-circuit in the supply voltage
lead to the motor holding brake
— Faulty motor holding brake
— Motor cable has short-circuit or earth
short
— Motor has short-circuit or earth short
— Resolver connector is not properly
plugged in
— Break in resolver cable, cable
crushed or similar
— Motor thermosensor has switched
— Loose resolver connector or break in
resolver cable
— Required holding torque too high
— Brake faulty
— Motor shaft axially overloaded
Kollmorgen | kdn.kollmorgen.com | June 2018
AKM Installation | 1 English
Measures to remove the cause
of the fault
— Supply ENABLE signal
— Check setpoint lead
— Correct the phase sequence
— Check brake controls
— Check mechanism
— Correct the phase sequence
— Replace resolver cable
— use motor default values
— Remove the short-circuit
— Replace motor
— Replace cable
— Replace motor
— Check connector
— Check cables
— Wait until the motor has
cooled down. Then investigate
why the motor becomes so hot.
— Check connector, replace
resolver cable if necessary
— Check the dimensioning
— Replace motor
— Check the axial load, reduce
it. Replace motor, since the bear-
ings have been damaged
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