Abnormal phenomena and processing methods of capacitors in operation - News - Global IC Trade Starts Here Free Products

Photocoupler

Capacitor failures and accidents may occur due to various reasons. Here are some common issues and their solutions:

1. Oil Leakage: During installation or maintenance, damage to the flange or weld can lead to oil leakage. Additionally, long-term operation might cause corrosion or manufacturing defects in the outer casing. This can reduce the impregnating agent, leading to moisture ingress and potential local breakdown.

2. Casing Expansion: Internal faults such as overvoltage, discharge to the casing, or component breakdown can generate gas inside the capacitor, increasing internal pressure and causing the casing to expand. Immediate action or power shutdown is necessary to prevent further damage.

3. Capacitor Explosion: In high-voltage capacitor banks without internal protection, a short circuit between poles can result in a sudden discharge. If the energy is too high, the capacitor may explode, potentially damaging other equipment or even starting a fire. Regular inspections and internal protection devices are crucial for safety.

4. Excessive Temperature Rise: Overvoltage, overload, dielectric aging, or poor cooling conditions can cause the temperature to rise beyond safe limits. This may shorten the capacitor’s lifespan or lead to breakdown. Monitoring ambient temperature and implementing cooling measures is essential. If the temperature cannot be controlled, the capacitor should be powered off immediately.

5. Porcelain Insulation Flashover: Surface contamination, environmental pollution, bad weather (like rain or snow), or overvoltage can cause flashovers on porcelain insulation. This can damage the capacitor or trigger a trip. In polluted areas, additional protective measures are recommended.

6. Abnormal Sounds: Unusual noises like “zizi” or “gugu” during operation usually indicate partial discharges inside or outside the capacitor. In such cases, it's important to stop the operation immediately and locate the faulty capacitor.

When handling capacitor-related accidents, operators should follow these key steps:

1. Power Off: The capacitor circuit breaker and isolator must be removed, or the fuse should be taken out to ensure no power is flowing through the system.

2. Discharge: Even though capacitors may self-discharge, residual charge can still be present. Operators must manually discharge the capacitor by first grounding the terminal and then discharging multiple times until there are no sparks or sounds left.

3. Use Protective Equipment: Always wear insulated gloves and use a shorting wire to connect the two poles during discharge. This is important because there may still be residual charge between the poles.

By following these procedures, operators can significantly reduce the risk of accidents and ensure safer handling of capacitor systems.