1.Analysis of cause of failure switching-on of the circuit breaker

（1）Solution for under-voltage coil not operating (normal voltage): change the under-voltage coil

（2）Solution for failure operation of switching-on coil after pressing the switching-on button: replace the under-voltage coil.

（3）Solution for poor contact of switching-on button: replace the

（4）Solution for burnt down of fusible core of control loop: replace the fusible core after confirming that the control loop is normal without short circuit.

（5）Solution for failure energy storage of circuit breaker: check control power voltage of the motor shall be≥ 85% .

（6）Control power voltage of the switching-on electromagnet shall be less than 85%. Solution: power voltage of switching-on electromagnet must be≥ 85%.

（7） Solution for damage of switching-on electromagnet: replace the switching-on electromagnet.

（8）Solution for poor contact of secondary loop of the drawing circuit breaker: after removing the drawer circuit breaker, move to the “connecting” position. Check whether the secondary loop is connected reliably.

（9） Solution for stop position at the universal changeover switch: rotate the switch to the left power transmission or the right power transmission。

2.Analysis for failure switching-off of main switch of the feeding cable cabinet

 （1）Solution for poor contact of switching-off button: replace the switching-off button.

 （2）Solution for burning down of switching-off coil: replace the switching-off coil.

3 Analysis for reverse rotation or failure rotation of main varmeter

（1） The capacitance compensation power too high or advanced: adjust the capacitance compensation to 0.92-0.97.

（2）Solution for incorrect phase sequence of feeding cable of transformer: re-adjust phase sequence.

（3）Solution for normal current and voltage loop: replace with varmeter.

4. Analysis for failure automatic feeding of capacitance cabinet

（1） Solution for failure wiring of current sampling signal wire: wire the current sampling signal wire.

（2） Solution for burnt down of fusible core of the control: replace the fusible core.

（3） Solution for too high voltage and over-voltage displayed by control: adjust over-voltage protection point.

（4）Solution for low current and control display in advance: after increasing current, it operates automatically.

（5）Solution for over-voltage display on the compensation instrument of the capacitance cabinet: set the voltage higher than actual voltage.

（6） Solution for failure wiring of current sampling signal wire: wire the current sampling signal wire.

（7）Solution for burning down of fusible core of compensation control instrument: replace the fusible core.

（8）Solution for low current: after the current has been increased, further commission and handle.

5.Analysis for failure rotation of watt hour meter of the drawer outlet wire

（1）Solution for checking poor contact of secondary plugs: adjust contact of the secondary plug.

（2）Solution for normal voltage and current: replace the watt hour meter.

6. Analysis for failure automatic feeding of changeover of dual power

（1）Solution for universal changeover switch switched to the automatic position: rotate the switch to the automatic position.

（2）Solution for manual changeover switch not rotated to automatic position: rotate the manual and automatic changeover switch to the automatic position.

（3）Solution for failure closure of over-voltage tripper: check whether the voltage is consistent with that of the tripper V ≥ 85%.

（4）Solution for failure closure of timely relay: check contacts 2#7# of the time relay are normal or not.

（5）. Solution for failure resetting of shunt mechanism of circuit breaker: check whether mechanical interlocking is loosened or not, and if there is any blocking.

7. Analysis for power factor of the capacitance cabinet not above 0.9

（1）Solution for lowered capacity of capacitor: replace capacitor.

（2） Solution for failure power connection of partial loops: check, handle and replace.