The Antek FU3AE‑04‑00 is a rack‑mounted digital frequency inverter rated for 380–480 VAC input and up to 3 A output at 50/60 Hz, designed for stepless speed control of low‑power three‑phase motors (≤1.1 kW). Common failure modes in this class include power supply over‑current protection trips, overheating of the internal MOSFET bridge, insulation degradation on the 24 VDC control bus, and loss of communication with host PLCs due to faulty edge‑connector pins. First‑check diagnostics: verify that the 380–480 VAC input is within spec and that the 24 VDC control supply is stable; inspect the edge connector for bent or corroded contacts; and review any stored error codes via the inverter’s front panel or diagnostic port to identify specific fault flags.[oss-gpt-20b]