LogrobotLM

LogrobotLM — AI fault diagnosis for ABB · KUKA · FANUC robots. It reads your robot backup in your browser (never uploaded) and pinpoints the fault. Try it free →

FANUC Alarm LECO-052 — Cap A over voltage (Cap A volts, Cap B volts)

FANUC LECO-052 (“Cap A over voltage (Cap A volts, Cap B volts)”): The voltage on one of the two input capacitor banks (bank A) has exceeded the high voltage limit. First check: Check the input power (voltage and frequency).

Updated 2026-09-17 · LogrobotLM reference

Description

The voltage on one of the two input capacitor banks (bank A) has exceeded the high voltage limit. This is normally caused by high input voltage but it could be caused by a faulty switch board, main capacitor, contactor, or V-to-F feedback signal.

Remedy

Check the input power (voltage and frequency). Verify the primary reconnect is properly configured for the input voltage.

Related codes

LECO-050Cap A under voltage (Cap A volts, Cap B volts)LECO-051Cap B under voltage (Cap A volts, Cap B volts)LECO-053Cap B over voltage (Cap A volts, Cap B volts)

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →