Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 76)

Chapter 4: Troubleshooting PC NC Maintenance Manual
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AL-33:The load is abnormal.
Error Contents The inverter output (U, V, W) is not connected (speed feedback is 0.)
Detection Methods If the following condition exists, the current is intercepted, and the
alarm is displayed. (load error detection selection bit C1-40.b7 is ON) /
(not orientation control mode) / (speed command is greater than 1%) /
(speed feedback is 0) (the above condition continued 5 seconds or
more)
AL-40, 41: Motor overheating 1 and 2
Error Contents AL-40: The motor temperature exceeded the upper limit.
AL-41: The motor temperature exceeded the upper limit for one minute
or more.
Detection Methods The motor temperature detection voltage is consistent from thermistor
signal THSA, THSB (2CN-8, 9).
If the motor temperature exceeds the motor overheating detection level
(determined by the motor parameter. Normally 155
ºC on F type),
minor fault display is performed due to motor overheating 1(AL-40).
The drive continues.
If the state of motor overheating continues for one minute, the current
is intercepted due to motor overheating 2(AL-41).
Improper drive by noise (encoder cable
characteristic defect) Check the encoder signal conductor is isolated from the main cir-
cuit wiring and other power lines.
Check encoder cable specification (twisted-pair shield wire) [rec-
ommended cable “KQVV-SW” by Fujikura-Densen Co.]
Motor encoder fault Confirm that there is no abnormal motor speed changes by the
speedometer indication or the drive state display (U1-01).
Exchange encoder or motor.
Control card fault Exchange unit (exchange control card)
Cause Measures
Inverter output opening Check inverter output (U, V, W) connection.
Motor encoder fault Confirm that there is no abnormal motor speed changes by the
speedometer indication or the drive state display (U1-01).
Exchange encoder or motor.