
3.2 Errors without alarm display and troubleshooting
3-4
3.2
Errors without alarm display and troubleshooting
The table below shows the causes and their remedies for the malfunctions accompanied with
no alarm generation.
Before you check or take a remedy for what is described in the half-tone meshing column,
you must turn off the power supply of Drive Unit.
Table 3.1 Errors without alarm display
Malfunction
Cause
Check point
Remedy
Motor does not start.
The power supply is
not turned on.
Check the voltage between
the main power supply
terminals.
Turn on the main power
supply.
Check the voltage between
the control power supply
terminals.
Turn on the control
power supply.
Check the voltage between
the main circuit power
supply terminals.
Turn on the main circuit
power supply.
Connection is loose
between Drive Unit
and motor.
Check the looseness of
connector.
Insert and fix the
connector securely.
Check the wiring.
Correct the wiring or
replace the cable.
Poor connection of
bus signal between
Drive Units. (CN5)
Check the looseness of
connector.
Insert and fix the
connector securely.
Check the wiring.
Replace the cable.
No
“Servo enable
”
signal.
Check signal
“DB3x.DBX93.7
”
on PLC
status screen (see 5.2).
Contact maintenance
stuff or machine tool
builder to check the
sequence of PLC.
Spindle Motor
winding is
disconnected.
Measure the resistance
between Spindle Motor
terminals.
Replace Spindle Motor.
The feed axis is
overloaded.
Try the no-load running.
Reduce the load or
consider replacement of
new machine with larger
capacity.
Spindle Motor is fault.
(Rotor and stator
contact each other by
fault of bearing.)
Separate Spindle Motor
from load and check
whether the shaft can be
rotated by hand.
Replace Spindle Motor.
Spindle Motor rotates
slowly or it is
prevented from
rotating by vibration.
The power line from
Inverter is
disconnected or
connected incorrectly.
Check wiring between
Inverter and motor.
Correct the wiring.
The encoder wiring is
disconnected, connect
incorrectly or the
encoder connector is
pulled out.
Check the wiring of
encoder signals.
Correct the wiring.
Motor encoder is fault. Turn the motor by hand
and check whether unusual
speed is displayed on
speed meter.
Replace motor or
encoder.