Yaskawa YASNAC PC NC Maintenance Manual - Manual (Page 77)

PC NC Maintenance Manual Chapter 4: Troubleshooting
4-56
Cause and measures
AL-42:Motor thermistor disconnection
Error Contents The thermistor for the motor temperature detection was disconnected.
Detection Methods The motor temperature detection voltage is consistent from thermistor
signal THSA and THSB (2CN-8,9).
Motor temperature is less than motor thermistor disconnection level (-
10ºC), the current is intercepted, and the alarm is displayed.
Cause and measures
Cause Measures
Motor overload Check the motor temperature by the drive state display (U7-01).
Motor cooling fan power wire discon-
nection Check wiring according to the interconnect chart.
Motor cooling fan fault Turn ON the power and check that the motor cooling air is nor-
mal.
Exchange the motor cooling fan or the motor.
Motor cooling ability decrease Check neither dust nor oil, etc. adhere to the motor cooling air
passage etc.
Thermistor signal conductor short-cir-
cuit Check motor thermistor signal conductor wiring.
Control card fault Exchange unit (exchange control card)
Cause Measures
Motor temperature is low. Check the motor ambient temperature.
Raise the ambient temperature to -10ºC or more.
Observe the motor temperature by the drive state display (U7-01).
Thermistor signal conductor short-circuit Check the motor temperature by the drive state display (U7-01).
Correct motor thermistor signal conductor wiring.
Control card fault Exchange unit (exchange control card)