Code SV0432: Converter: control power supply undervoltage
Issue Description & Safety Warning
The Fanuc Alpha-i Servo Spindle Amplifier has triggered a critical Converter: control power supply undervoltage alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
Amplifier LED display: 6 Also shown as: SV0432/SV0602 (15i), SV0432/SV0602 (30i/31i/32i), SV0432/SV0602 (0i-D) Cause: (1) Meaning The main circuit capacitor was not recharged within the specified time. (2) Cause and troubleshooting (a) Too many Servo Amplifier and/or Spindle Amplifier units are connected. → Check the specification of the PSM. (b) The DC link is short-circuited. → Check the connection. (c) The recharge current limiting resistor is defective. → Replace the distributing board.
Source: Fanuc αi Servo/Spindle Amplifier Maintenance Manual (B-65285EN/04) — Part II Troubleshooting
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Fanuc Alpha-i Servo Spindle Amplifier Alarms
Fanuc controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code SV0432 on the Alpha-i Servo Spindle Amplifier identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Fanuc's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 135 Fanuc Alpha-i Servo Spindle Amplifier codes.
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