
8
8.3 Alarms Indicated on the Screen of the Power Mate CNC Manag-
er (FANUC Servo Motor Amplifier β Series (I/O Link Option))
540
No. CountermeasureDescription
LED
display
[SVU–40, SVU–80]
An overcurrent alarm or IPM
alarm is issued.
This alarm is issued in the
following cases:
S This alarm is issued when
an excessively large cur-
rent flows in the main cir-
cuit.
S This alarm is issued when
an error (overcurrent,
overheat, low IPM control
power supply voltage) is
detected in the IPM (semi-
conductor driving the mo-
tor).
412
(1) Check whether a valid motor number is specified in pa-
rameter(*) 30.
(2) Check whether the standard values are specified in the
current control parameters(*) for servo control.
Correct current control is possible only when the stan-
dard values are specified for the following parame-
ters(*):
No.70, 71, 72, 78, 79, 84, 85, 86, 87, 88, 89, 90
(3) Turn off the servo amplifier unit for about ten minutes,
then release the emergency stop state. If no overcur-
rent alarm is issued, The IPM protection function
(against overheat) may be operating. Possible causes
of overheat include a high ambient temperature and a
too severe motor operating condition. Check the
cause.
³ If an overcurrent alarm is issued, go to (4).
(4) Disconnect the power line from the servo amplifier unit
connector. Then, release the emergency stop state.
³ If an overcurrent alarm is issued, the IPM protection
function (against overcurrent, low control power
supply voltage, overheat) may be operating or de-
fective. Replace the IPM or servo amplifier unit.
³ If no overcurrent alarm is issued, go to (5).
(5) Disconnect the power line from the amplifier connector.
Check the insulation between the ground and each of
U, V, and W.
³ If a short–circuit is found between the ground and U,
V, or W of the motor, replace the motor.
³ If the insulation is satisfactory, replace the power
line.
(6) Connect the power line. Observe the waveform of the
motor current (IR, IS) while the motor is accelerating or
decelerating.
³ If the motor current (IR, IS) does not exhibit a normal
sine wave, replace the servo amplifier unit.
(7) Check whether the waveform of the motor current (IR,
IS) contains noise.
³ If it contains noise, take appropriate measures
against noise, such as grounding the shield.
³ If it does not contain noise, replace the servo ampli-
fier unit.
(8) If (1) to (7) above are not the cause of the alarm, the
pulse coder, or command cable may be defective.