A: 1. Immediately shut down the equipment safely and disconnect the power supply. Wait for at least the time specified on the inverter.

2. Replace the damaged capacitor. Bulging capacitors are irreversible and cannot be repaired; replacement is mandatory. Use a capacitor of the same model and specifications, or replace it with a capacitor board provided by INVT. Before removing the old capacitor, take a photo of its wiring configuration with your phone to ensure the new capacitor is connected correctly. Note the polarity (electrolytic capacitors are polarized). Carefully remove the old capacitor and securely install the new one. Ensure terminals are tightened to prevent poor contact and overheating.

3. Causes and Prevention

1) Excessive Ambient Temperature: Poor ventilation at the inverter installation site, high ambient temperature, or dust clogging the heat sink.
Countermeasure: Improve ventilation conditions, clean the cooling fan and air ducts, ensure sufficient space around the inverter, and install air conditioning or forced ventilation equipment if necessary.

2) Capacitor Aging: Capacitors are consumables with a limited lifespan (typically several years), and aging accelerates in harsh environments.
Countermeasure: For inverters reaching their service life or in critical applications, consider implementing preventive maintenance with regular inspections or capacitor replacements.

3) Harmonic currents or overvoltage: Unstable grid voltage, frequent emergency stops/starts, or significant load fluctuations can cause DC bus voltage fluctuations or generate substantial harmonics, intensifying capacitor heating.

Countermeasure: Monitor grid voltage. Install input reactors in locations with significant grid fluctuations.

4) Component failure: Issues like rectifier bridge malfunctions allowing AC leakage into the DC side can accelerate capacitor damage.
Countermeasure: After capacitor replacement, have a professional conduct a comprehensive inspection.