There are two kinds of common faults of high-voltage switch body and oil switch body.

1. Common faults and treatment methods of low oil circuit breaker body

(1) Oil leakage fault of rocker shaft.

Causes: ① there are pores, cracks, damages and other mechanical damages or burrs on the framework sealing ring; ② The rotating shaft and shaft hole are not smooth,

Burrs.

Treatment method: ① carefully check the appearance of the framework sealing ring, turn the inner ring over for inspection, and replace it in case of damage and defect;

② Treat with oz abrasive cloth to make the inner wall of shaft and hole smooth.

(2) The static contact finger falls off and is stuck in the arc extinguishing sheet and cannot be closed.

Causes: ① the spring plate is bent and loses elasticity; ② The tolerance fit between aluminum grid and contact base is too large.

Treatment method: ① replace the qualified spring plate; ② Replace the qualified aluminum grid or contact base.

(3) Burn failure of contact parts between arc contact finger, spring blade, contact base and grid

Cause: the spring plate loses elasticity, resulting in poor contact between the contact finger and the contact seat.

Treatment method: replace the qualified spring.

(4) Arc contact refers to the falling off fault of copper tungsten alloy block.

Cause: poor welding.

Treatment method: replace the integral sintered contact.

(5) The red copper part of the contact finger and arc striking contact finger is burnt.

Cause: the steel ball stroke of static contact seat check valve is too large.

Treatment method: turn the check valve in another direction, re punch and add rivets to make the stroke of the steel ball 0.5-x1 mm, or replace the aluminum alloy ball.

(6) The center of the moving and static contacts is not correct. When closing, it strikes the contact finger, causing it to deform and fall down.

Causes: ① the spring coil between the lower pressing ring and the edge cylinder is biased; ② The 4 hexagon socket bolts on the lower pressing ring are tightened unevenly; ③ The static contact seat is biased.

Treatment method: ① replace the flattened and deformed spring ring Reassemble so that all springs enter the groove; G4 hexagon socket bolts shall be tightened evenly diagonally; ③ Loosen the 4 hexagon socket bolts between the upper cap and the upper wiring base, adjust the assembly position of the static contact base, re tighten the 4 hexagon socket bolts diagonally and evenly, or loosen the 3 bolts between the contact frame and the contact base at the same time to adjust the position of the contact base.

(7) Oil leakage fault of buffer disc at the bottom of base

Causes: ① the fit tolerance between the seal ring and the groove on the disc is too large, resulting in insufficient compression of the seal ring; ② The seal ring changes permanently during operation.

Treatment method: ① replace the thicker sealing ring, or turn the disc groove shallower to make the compression of the sealing ring reach about 1 / 3; ② Replace the sealing ring with a new one.

2. Common faults and treatment methods of electromagnetic operating mechanism of low oil circuit breaker

When the electric operation fails, judge whether it is electrical fault or mechanical fault first.

When the electric closing fails, if the DC contactor HC does not act, it is generally the fault of the electrical control circuit; If the closing armature acts, but it is jammed or the mechanism is not firmly hung, resulting in falling off, it is generally a mechanical failure.

When the electric opening fails, if the opening armature TQ does not act, it is generally the fault of the electrical control circuit; If the opening armature acts, it is generally a mechanical failure.

(1) Opening failure.

Causes: ① the positioning screw is loose and displaced, causing the intermediate shaft of the opening connecting plate to be too low; ② The opening electromagnet core is jammed in motion; ③ The fixed stop pin of the opening electromagnet is loose, resulting in the falling or even falling of the iron core; ④ The stroke of opening iron core is too large; ⑤ The electrical circuit is blocked.

Treatment method: ① readjust the positioning screw and tighten the lock nut; ② Find out the reasons for the jammed iron core and carry out targeted treatment; ③ Push the stop nail firmly into the socket, and install a support plate at the lower part of the opening iron core; ④ Adjust the stroke of iron core to reduce it properly; ⑤ If the DC contactor HC acts, the closing coil circuit is disconnected For example, the fuse 3rd (4rd) is blown or the circuit element is poorly wired, and the closing coil HQ is disconnected; ⑥ If the DC contactor HC does not act, it is the closing circuit disconnection, such as the closing contactor HC coil disconnection or inter turn short circuit, auxiliary contact failure, loose circuit terminal and other reasons; ⑦ Use the light to check the line and eliminate the fault in time.

(2) Closing failure.

Causes: ① the position of the intermediate shaft of the opening connecting plate is too high; ② The washer on the upper edge of the closing iron core is biased; ③ The moving contact of the closing contactor is stuck against the arc extinguishing cover; ④ The electrical circuit is blocked; ⑤ When closing, due to the vibration of the mechanism, the opening iron core jumps up and hits the intermediate shaft of the opening connecting plate.

Treatment method: ① readjust the position of the intermediate shaft of the opening connecting plate. However, it shall ensure reliable opening under low opening voltage; ② Make both ends of the outer copper sleeve of the closing iron core accurately enter the upper and lower choke slots, and place the positive edge washer; ③ Handle the moving contact so that the moving contact will not jam and touch the arc extinguishing cover; ④ If the DC contactor HC acts, the circuit of the closing coil is broken, such as the fuse 3rd (4rd) is blown or the circuit components are poorly wired, the closing coil HQ is broken, etc; ⑤ If the DC contactor HC does not act, it is the closing circuit disconnection, such as the closing contactor HC coil disconnection or inter turn short circuit, auxiliary contact failure, loose circuit terminal and other reasons; ⑥ If there is a supporting plate for opening the electric ferromagnetic, loosen the if nail on the upper part of the static iron core.

(3) & ldquo; occurs when closing; Jump & rdquo;. Failure to close the brake.

Causes: ① the closing contact of auxiliary switch is opened too early; ② The top rod of closing iron core is too short.

Treatment method: ① adjust the auxiliary switch contact to open it after the circuit breaker contact is connected, and ensure that the disconnection distance of the auxiliary switch contact at the closing position is not less than 2 mm; ② Adjust the top rod of the closing iron core to make the overshoot gap reach 1 O- 1. 5 mm,

3. Common faults and treatment methods of CT8 spring operating mechanism of low oil circuit breaker

([) opening failure.

Causes: ① the half shaft buckle is too deep; ② The coil and iron core of each release have different axes, and the movement of the iron core is blocked; ③ Improper adjustment of auxiliary contacts.

Treatment method: ① readjust according to the requirements of maintenance process rules; ③ Loosen and adjust the iron choke bolts of the electromagnet connected in series so that the axis of the iron core is on the line; ③ Readjust the auxiliary switch to make its contact switch accurately and reliably.

(2) Closing failure, mechanism immobility failure.

Causes: ① the electrical operation circuit is blocked; ③ The relative position between the closing coil and the iron core is incorrect, such as the iron core is inserted into the coil too much or too little; ③ The positioning piece is buckled too deep.

Treatment methods: ① check the line by turning on the light and eliminate the fault in time; ② Properly adjust the size of the iron core inserted into the coil; ③ Adjust the buckle depth properly

(3) Closing failure: the spring releases energy but the closing is not successful.

Causes: ① there is no amount of buckle in the half shaft; ② The output shaft connecting rod is too long.

Treatment methods: ① readjust the number of people deducted; ② Readjust the length of the connecting rod.