Introduction to Power Capacitor Switching and Discharge

Power capacitor connection and disconnection

(1) The electrical capacitor unit shall check the discharge network with a MEU meter before connection.

(2) The following must be taken into account when switching on and off the capacitor set:

When the voltage on the bus(bus) exceeds the maximum allowable value of 1.1 times the rated voltage, it is forbidden to connect the capacitor group to the grid.

No reconnection shall be made within 1 min of the disconnection of the capacitor group from the grid, except in the case of automatic repeated access.

When switching on and off the capacitor group, a circuit breaker that can not produce dangerous overvoltage should be selected, and the rated current of the circuit breaker should not be less than 1.3 times the rated current of the capacitor group.

Discharge of electrical capacitors

(1) The capacitor shall be discharged automatically each time it is disconnected from the grid. The end voltage of the capacitor is rapidly reduced. Regardless of the rated voltage of the capacitor, the end voltage of the capacitor should not exceed 65V after the capacitor is disconnected from the grid.

(2) In order to protect the capacitor group, the automatic discharge device shall be installed on the load side of the circuit breaker of the capacitor and shall often be in direct parallel with the capacitor (no circuit breakers, isolation switches, and fuses are allowed in the middle). Capacitors with non-dedicated discharge devices, such as voltage Transformers for high voltage capacitors, incandescent bulbs for low voltage capacitors, and capacitors directly connected to Motors, may not be fitted with separate discharge devices. When using light bulbs, in order to extend the service life of light bulbs, the number of series light bulbs should be increased appropriately.

(3) Prior to contact with the conductive part of the capacitor disconnected from the grid, the separate discharge must be performed with an insulated grounding metal rod, the outline end of the short-connected capacitor, even if the capacitor has been automatically discharged.

The page contains the contents of the machine translation.