EO charger makes a loud buzzing or chattering noise during charging.

Safety first: Buzzing can indicate arcing. If you smell burning or see sparks, isolate power immediately.

• Confirm source of noise: With the cover on, listen carefully to identify whether the sound comes from the contactor area.
• Inspect contactor mounting: With power off and cover removed, ensure the contactor is firmly secured to its DIN rail or mounting plate.
• Check coil voltage and wiring: Verify that the contactor coil is wired correctly and that the supply to the coil matches its rated voltage.
• Measure supply stability: A qualified electrician should check for significant voltage dips or fluctuations that could cause coil chatter.
• Replace contactor if worn: If mechanical wear or pitting is evident, replace the contactor with the EO‑specified model.