Dongli Electric

Classification and Maintenance of High and Low Voltage Switchgear

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Classification and Maintenance of High and Low Voltage Switchgear

High and low voltage switchgearThe classification is mainly:

1. According to the installation method of circuit breaker, it can be divided into removable switch cabinet and fixed switch cabinet.

2. According to the different cabinet structure, it can be divided into metal closed switch cabinet, metal closed armored switch cabinet and open switch cabinet.

3. According to different voltage levels, it can be divided into high-voltage switchgear, medium-voltage switchgear and low-voltage switchgear.

High and low voltage switchgearOverhaul

Detailed maintenance plan shall be prepared for maintenance, which shall be discussed and revised in the work area. Operation can only be carried out after being submitted to the department for approval, specifically in the following five aspects:

(I) vacuum circuit breaker maintenance. Clean the insulator and vacuum chamber of the circuit breaker, wipe it clean with a rag, check that the energy storage spring should be free of deformation and corrosion, the transmission shaft should rotate flexibly, and inject lubricating oil. All parts should be normal and intact. Due to the loosening of screws and cotter pins caused by vibration during opening and closing, the normal operation of the mechanism is hindered. Therefore, all fixing screws and cotter pins should be complete and reliable, and all bolts should be firmly connected and stressed evenly, check that the three-phase contact spring is free of deformation and the contact surface is free of heating and discoloration.

Maintenance of (II) microcomputer protection unit. Clean the external terminal of the protection unit and brush it with dry flat oil brush. All components shall be in good condition without loosening and heating. The protection setting value and pressing plate shall be checked according to the account. The protection unit shall be verified. Before replacing the protection unit, the unit type shall be carefully checked and submitted to the electric control department for approval according to the two versions of drawings and construction scheme provided by the new protection unit.

(III) current transformer maintenance. Wipe the surface of the transformer with a rag to check that the secondary terminal and iron core of the transformer are well grounded. After removing all primary wires of the current transformer, check the model of the equipment carefully before replacing the current transformer.

Overhaul of (IV) overvoltage absorption device. Wipe the surface with a rag, remove the primary line, do not pull up the primary line, check according to regulations, and replace if it is unqualified.

(V) minor repairs to all items.