1. Common faults of capacitors, When one of the following conditions of the capacitor is found, the power supply should be cut

off immediately.

(1) The capacitor shell expands or leaks oil.

(2) Casing rupture, flashover and spark.

(3) Abnormal sound inside the capacitor.

(4) The temperature rise of the shell is higher than 55 C and the temperature indicator falls off.

2. Fault handling of capacitor(1) When the capacitor explodes and catches fire, immediately disconnect the power supply and use sand and dry fireextinguishers to extinguish the fire.

(2) When the fuse of the capacitor is blown,it shall be reported to the dispatcher, and the circuit breaker of the capacitor shall beopened after obtaining the consent, Cut off the power supply to discharge it, and conduct external inspection first, such aswhether there is flashover trace outside the casing, whether the casing is deformed, whether there is oil leakage and whether thereis short circuit phenomenon in the grounding device, etc, and shake and measure the insulation resistance value between polesand pole to ground, check whether the capacitor bank wiring is complete and firm, whether there is phase loss phenomenon,if nofault phenomenon is found, replace the insurance and put into operation. If the fuse is still blown after power transmission, thefaulty capacitor should be withdrawn and power transmission to the rest should be resumed. If the circuit breaker trips at thesame time of fuse fusing, it shall not be forced, Must wait until the above inspection is completed and the insurance is replacedbefore putting in.

3. Safety matters when dealing with faulty capacitors, Since the two poles of the capacitor have the characteristics of residualcharge, it should first try to discharge its charge, otherwise it is prone to electric shock accidents, When dealing with the faultcapacitor, the circuit breaker of the capacitor bank and its upper and lower isolating switches should be opened first. If the fuse isused for protection, the fuse tube should be removed first, At this time, although the capacitor bank has been discharged by itselfthrough the discharge resistor, there will still be some residual charges, so manual discharge must be carried out. When

discharging,first fix the grounding end of the grounding wire with the grounding grid, then discharge the capacitor several timeswith the grounding rod until there is no spark and discharge sound, and finally fix the grounding wire, At the same time,it shouldalso be noted that if the capacitor has internal disconnection,fuse fusing or poor lead contact, there may be residual chargebetween its two poles, and these residual charges will not be discharged during automatic discharge or manual discharge.Therefore,the operation or maintenance personnel should wear insulating gloves before contacting the faulty capacitor, andshort-circuit the two poles of the faulty capacitor with a short-circuit to discharge it. In addition, the capacitor connected in seriesshould also be discharged separately.