Omron G5 Series User Manual page 455

Alarm No.
Name
Main Sub
13 0 Main Power Supply
Undervoltage
(insufficient voltage
between P and N)
1 Main Power Supply
Undervoltage
(AC cutoff detected)
14 0 Overcurrent
1 IPM Error
OMNUC G5-series (Pulse-train Input Type) AC Servomotors and Servo Drives User's Manual
Cause
If Undervoltage Alarm Selection (Pn508)
is set to 1, a momentary power
interruption occurred between L1 and L3
for longer than the value set in
Momentary Hold Time (Pn509).
Alternatively, the voltage across the
positive and negative terminals in the
main power supply converter dropped
below the specified value while the servo
was ON.
200-V products: Approx. 110 VDC
(Approx. 75 VAC)
• The power supply voltage is low.
• A momentary power interruption
occurred.
• Insufficient power supply capacity:
The power supply voltage dropped
because there was inrush current
when the main power supply was
turned ON.
• Phase loss:
A Servo Drive with 3-phase input
specifications was operated with
single-phase power supply.
• The Servo Drive is faulty (circuit fault).
The current flowing between the positive
and negative terminals in the converter
exceeded the specified value.
• The Servo Drive is faulty (faulty circuit,
faulty IGBT part, etc.).
• The Servomotor cable is short-
circuited between phases U, V, and W.
• The Servomotor cable is ground-
faulted.
• Motor windings are burned out.
• The Servomotor wiring contacts are
faulty.
• The relay for the dynamic brake has
been welded due to frequent servo
ON/OFF operations.
• The command pulse input timing is the
same as or earlier than the Servo ON
timing.
10 Troubleshooting and Maintenance
Measures
Measure the voltage across the L1, L2,
and L3 lines on the connectors and the
terminal block.
• Increase the power supply voltage.
Change the power supply.
• Eliminate the cause of the failure of the
electromagnetic contactor on the main
circuit power supply, and then turn ON
the power again.
• Check the value set in Momentary
Hold Time (Pn509). Set each phase of
the power supply correctly.
• Increase the power supply capacity.
Refer to 2-3-3 Servo Drive and
Servomotor Combination Tables on
page 2-11 for information on the power
supply capacity.
• Connect each phase (L1, L2, and L3)
of the power supply correctly. Use L1
and L3 for single-phase 100 V and
single-phase 200 V.
• Replace the Servo Drive.
• Disconnect the Servomotor cable, and
turn ON the servo. If the problem
immediately recurs, replace the Servo
Drive with a new one.
• Check to see if the Servomotor cable
is short-circuited between phases U, V
and W by checking for loose wire
strands on the connector lead.
Connect the Servomotor cable
correctly.
• Check the insulation resistance
between phases U, V, and W of the
Servomotor cable and the grounding
wire of the Servomotor. If the
insulation is faulty, replace the
Servomotor.
• Check the balance between the
resistance of each wire of the
Servomotor. If resistance is
unbalanced, replace the Servomotor.
• Check for missing connector pins in
Servomotor connections U, V, and W.
If any loose or missing connector pins
are found, secure them firmly.
• Replace the Servo Drive.
The servo does not turn ON for a
period of 3 minutes after the use of the
dynamic brake.
• Wait at least 100 ms after the servo
has turned ON, then input commands.
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