YASKAWA Σ-V Series User Manual page 278

Problem Probable Cause
Noise interference due to improper
specifications of the cable for con-
necting serial converter unit.
Noise interference because the
length of the cable for connecting
serial converter unit is too long.
Noise influence due to damaged
cable for connecting serial con-
verter unit
Excessive noise interference to the
cable for connecting serial con-
verter unit
FG electrical potential varies by
Position Error
influence of such machines on the
linear servomotor side as welders.
(without alarm)
SERVOPACK pulse count error due
to noise
Excessive vibration and shock to
the serial converter unit
Noise interference due to improper
I/O signal cable specifications
Noise interference due to length of
I/O signal cable
A linear scale fault occurred.
(The pulse count does not change.)
A SERVOPACK fault occurred.
Ambient operating temperature is
too high.
Linear servomotor surface is dirty.
Servomotor
Overheated
Linear servomotor overloaded
Polarity detection is not performed
correctly.
8.3 Troubleshooting Malfunction Based on Operation and Conditions of the Linear Servomotor
Investigative Actions
The specifications of the cable for
connecting serial converter unit
must be:
Twisted-pair or twisted-pair
shielded wire with core
2
0.12 mm min. and tinned annealed
copper twisted wire.
Check the length of the cable for
connecting serial converter unit.
Check the cable for connecting
serial converter unit to see if it is
bent or its sheath is damaged.
Check if the cable for connecting
serial converter unit is bundled with
a high-current line or near high-cur-
rent line.
Check if the machine is correctly
grounded.
Check if the I/O signal cable from
the serial converter unit is influ-
enced by noise.
Check if machine vibration
occurred or serial converter unit
mounting such as mounting surface
precision, fixing is incorrect.
The specifications of the I/O signal
cable must be:
Twisted-pair or twisted-pair
shielded wire with core
2
0.12 mm min. and tinned annealed
copper twisted wire.
Check the I/O signal cable length.
−
−
Measure the linear servomotor
ambient operating temperature.
Check visually.
Check the load status with monitor.
Check if the value of Un004 (Elec-
tric Angle 2) at an arbitrary position
is between ±10 degrees.
Corrective Actions
Use the cable for connecting serial
converter unit with the specified
specifications.
The length of the cable for connect-
ing serial converter unit must be 20
m max.
If the cable is damaged, replace the
cable for connecting serial con-
verter unit, and correct the cable
layout.
Change the layout of the cable for
connecting serial converter unit so
that no surge voltage is applied.
Ground the machine separately
from encoder side FG.
Take a measure against noise for the
serial converter unit wiring.
Reduce the machine vibration or
mount the serial converter unit
securely.
Use I/O signal cable with the speci-
fied specifications.
The I/O signal cable length must be
less than 3 m.
Replace the linear servomotor.
Replace the SERVOPACK.
Reduce the ambient operating tem-
perature to 40°C max.
Clean dust and oil from linear ser-
vomotor surface.
If overloaded, reduce load or
replace with larger capacity SER-
VOPACK and linear servomotor.
Correct the settings for the polarity
detection related parameter.
8
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