Yaskawa YASNAC PC NC Maintenance Manual User Manual
Page 78
Chapter 4: Troubleshooting
PC NC Maintenance Manual
4-57
AL-43, -44: Heat sink overheating 1 and 2
Error Contents
AL-43: The heat sink temperature exceeded the upper limit.
AL-44: The heat sink temperature exceeded the upper limit for one
minute or more.
Detection Methods
The heat sink temperature detection voltage is consistent from ther-
mistor signal (7CN-39) for the heat sink temperature detection.
If the heat sink temperature exceeds the heat sink overheating detection
level (determined by the inverter capacity), a minor fault display is per-
formed due to heat sink overheating 1(AL-43). The drive continues.
If the state of heat sink overheating continues for one minute, the cur-
rent is intercepted due to heat sink overheating 2(AL-44).
Cause and measures
Cause Measures
Inverter overload
Check the heat sink temperature by the drive state display (U1-13:
heat sink temperature).
Inverter cooling fan fault
Turn ON the power and check that the motor cooling air is normal.
Exchange the inverter cooling fan.
Heat sink cooling ability
decrease
Check neither the heat sink dust nor oil, etc. adhere.
Thermistor signal conductor
short-circuit
Check heat sink thermistor signal conductor wiring.
Control card fault
Exchange unit (exchange control card)