Applicable Systems
Series 0i
Series 16/18/21
Alpha
Beta
Symptoms
The servo control unit reports alarm SV 440 (CNV. EX DECELERATION POW.) on the 4th axis. The servo amplifier for the 4th axis may display an error state on its status LEDs. The axis may stop or fail to move until the condition is corrected.
Possible Causes
- 4th axis servo amplifier fault: CNV. EX DECELERATION POW.
- 4th axis servo amplifier wiring or connector issue
- 4th axis servo amplifier power supply problem
Troubleshooting Steps
- Step 1: Check the 4th axis servo amplifier status LEDs and record the displayed state.
- Step 2: Verify all power and signal cables to the 4th axis servo amplifier are securely connected.
- Step 3: Measure the 4th axis amplifier DC link and control voltages per the maintenance manual.
- Step 4: If the 4th axis amplifier is faulty, replace it with a matching FANUC unit.
How to Reset
Power off the machine, correct the fault condition, power on, and press RESET. If the alarm reappears, service the servo amplifier.
Common Replacement Parts
- varies: 4th axis servo amplifier (if confirmed faulty)
Frequently Asked Questions
- Q: What does Fanuc SV 440 4th alarm mean?
Fanuc SV 440 4th indicates a servo alarm (CNV. EX DECELERATION POW.) on the 4th axis. Check the servo amplifier and its connections.
Source: HelmanCNC.com - https://www.helmancnc.com/fanuc-alarm-codes-list/ (servo alarm with n-th axis)
Category: CNC