Capacitors play an important role in tuning, bypass, coupling and filtering circuits. Transistor radio tuning circuit to use it, color TV coupling circuit, bypass circuit also need to use it. Solid state capacitor manufacturers capacitor common faults and treatment methods?

1. Common faults of capacitor. When one of the following conditions of the capacitor is found, the power supply shall be cut off immediately.

(1) Expansion or oil leakage of capacitor shell.

(2) The bushing is broken, flashover occurs, and there are sparks.

(3) The sound inside the capacitor is abnormal.

(4) When the shell temperature rises above 55 ℃, the temperature indicator falls off.

2. Fault treatment of capacitor

(1) When the capacitor explodes and catches fire, immediately cut off the power supply and extinguish the fire with sand and dry fire extinguisher.

(2) When the fuse of the capacitor is blown, it shall be reported to the dispatcher, and the circuit breaker of the capacitor shall be opened after obtaining approval. Cut off the power supply and discharge it. First, conduct external inspection, such as whether there is flashover trace on the outside of the bushing, whether the shell is deformed, whether there is oil leakage and whether there is short circuit in the grounding device. Shake the insulation resistance value between the poles and between the poles and the ground, and check whether the capacitor bank wiring is complete and firm, and whether there is phase loss. If no fault is found, replace the fuse and put it into operation.

If the fuse is still broken after power transmission, the faulty capacitor shall be removed and the power transmission to the rest shall be resumed. If the circuit breaker also trips when the fuse is blown, the forced transmission is not allowed at this time. It shall not be put into operation until the above inspection is completed and the insurance is replaced.

(3) If the circuit breaker of the capacitor trips and the shunt fuse is not broken, discharge the capacitor for three minutes before checking the power cable of the circuit breaker current transformer and the outside of the capacitor. If no abnormality is found, it may be caused by external fault bus voltage fluctuation. After inspection, it can be put into trial operation; Otherwise, a comprehensive power on test should be conducted for the protection. Through the above inspection and test, if the cause can not be found, it is necessary to act according to the system and gradually test the capacitor. No trial investment shall be made until the cause is found out.

3. Safety precautions when handling faulty capacitors. As the two poles of the capacitor have the characteristics of residual charge, we should try to discharge the charge first, otherwise electric shock accident is easy to occur. When dealing with the faulty capacitor, the circuit breaker of the capacitor bank and its upper and lower isolating switches should be opened first. If the fuse protection is adopted, the fuse tube should be removed first.

At this time, although the capacitor bank has been discharged by itself through the discharge resistance, there will still be some residual charges, so it must be artificially discharged. When discharging, the grounding terminal of the grounding wire should be fixed with the grounding grid, and then the grounding rod should discharge the capacitor for many times until there is no spark and discharge sound, and then the grounding wire should be fixed.

At the same time, it should also be noted that if the capacitor has internal disconnection, fuse fusing or poor lead contact, there may be residual charges between the two poles, and these residual charges will not be discharged during automatic discharge or manual discharge. Therefore, operators or maintenance personnel should wear insulating gloves before contacting the faulty capacitor, and use short circuit to short the two poles of the faulty capacitor to make it discharge. In addition, the capacitor connected in series should be discharged separately.