Fanuc alarm SV0434: INV. LOW VOLT CONTROL
αi/βi Servo (SV0xxx) · Fanuc 0i-D
What it means
The servo amplifier's control-power supply voltage dropped below specification. Low control voltage starves the amplifier's logic and gate-drive circuits and commonly stems from poor control-board seating, a failing control supply, or input-side problems. Reseat the control PCB and check incoming line voltage balance; otherwise the amplifier needs exchange.
Likely causes
- Control PCB not fully seated in amplifier
- Deteriorated control power supply circuitry
- Undervoltage or imbalance in incoming 3-phase supply
- Wiring drop across input terminals/connectors
Need the part urgently?
Send us alarm SV0434 with your machine details — typical RFQ turnaround is 24–48h.