2154

Common Causes

• Input voltage drop, power failure, blown fuse in the input power circuit, or instantaneous power interruption (low voltage case)
• Power unit failure (high voltage or abnormal control power cases)
• Regenerative circuit overload from heavy deceleration duty
• Power unit heat sink overheat from fan failure or blocked airflow

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code X=0 = DC voltage alarm; ZZ shows detected DC voltage in hex (3.9V units).; code X=1 = Abnormal input voltage; ZZ shows detected AC voltage in hex (3.1V units).; code X=2 = Abnormal control power; ZZ: 1=+5V, 2=+12V, 3=-12V abnormal.; code X=3 = Abnormal control status; ZZ: 1=converter over current, 2=abnormal power element, 3=converter short circuit, 4/5=abnormal regenerative circuit.; code X=4 = Overload in regenerative circuit.; code X=5 = Heat sink overheat.; code X=6 = CPU error.
2. 2Read the code: the X digit is the alarm number (0 DC voltage, 1 abnormal input voltage, 2 abnormal control power, 3 abnormal control status, 4 regenerative overload, 5 heat sink overheat, 6 CPU error); the ZZ data field gives measured voltage or sub-cause, e.g. for X=2: 1 is +5V abnormal, 2 is +12V abnormal, 3 is -12V abnormal.
3. 3For input voltage or low voltage codes, check the shop supply: measure incoming line voltage, look for a blown fuse in the input power circuit, and ask whether a momentary power interruption occurred.
4. 4For heat sink overheat (X=5), check the power unit cooling fans and heatsink airflow, clean out dust and swarf, and confirm cabinet cooling is working before restarting.
5. 5For regenerative overload (X=4), reduce aggressive deceleration in the program and inspect the regenerative resistor or circuit type indicated by the ZZ data.
6. 6Lock out power and observe capacitor discharge precautions before opening the unit; if the code indicates abnormal control power or high voltage with normal input, the power unit itself must be inspected or exchanged.
7. 7Record the full code and axis before cycling power; if the same code returns immediately at power-up, have the power unit and its control power supply professionally checked.