Omron CJ1W-C113 - REV 02-2008 Operation Manual page 340

Troubleshooting Tables
No. Problem
25 The origin estab-
lished by the origin
search sometimes
changes.
26
27 Motor rotation is
unstable.
28
29
30
31
32
Probable causes
There is some looseness in
couplings or other mechanical
connections.
There is no Z-phase margin.
There is no margin for the ori-
gin input signal.
The Servo Motor power lines
and encoder lines are wired
incorrectly.
There is eccentricity in the
couplings connecting the
motor axis and the mechani-
cal system. There may be
loose screws or load torque
fluctuation due to the meshing
of pulley gears.
The gain adjustment is insuffi-
cient.
The wrong Servomotor is
selected (so it cannot be
adjusted).
The Servomotor bearings are
damaged.
The Servomotor windings are
disconnected.
Items to check
Check whether there is any devi-
ation from the markings at the
couplings between the motor
and axes, or at any other con-
nections.
Check the Z-phase margin using
the procedure given in 6-8 Z-
phase Margin. If the value is
near one rotation (the number of
pulses in one rotation), or near
zero, a deviation of one motor
revolution may occur at the time
of the origin search due to
minute changes in the timing of
sensor inputs.
Check the Servo Motor power
lines and encoder lines.
Check the machinery. Try turning
the motor with no load (i.e., with
the machinery removed from the
coupling).
---
Check the torque and inertia rat-
ings and select another Servo-
motor.
Turn OFF the Servo Drive power.
If the Servomotor has a brake,
turn ON the brake power supply
and release the brake, and then
manually turn the motor's output
axis with the motor's power line
disconnected (because the
dynamic brake may be applied).
With a tester, check resistance
between the Servomotor's U, V,
and W power lines. There should
be a proper balance between the
line resistances.
Section 11-1
Remedy
Tighten up the loose con-
nections.
Remove the motor cou-
pling and adjust it by
about a 1/4 turn, so that
the Z-phase margin
pulses will be equivalent
to about half of a Servo-
motor rotation, and then
try executing the origin
search again.
Correct the wiring.
Adjust the machinery.
Execute Servomotor
autotuning.
Manually adjust the Ser-
vomotor gain.
Change to a suitable Ser-
vomotor.
Replace the Servomotor.
Replace the Servomotor.
313