What are the common faults of 10kV vacuum circuit breakers and how to handle them?
1. Since the vacuum bubble itself does not have a device to monitor the vacuum characteristics, the reduction of the vacuum degree cannot be judged by the maintenance and operation personnel, and the fault is not easy to be discovered, and its degree of danger is far greater than the dominant fault. The reduction of the vacuum degree will not be able to extinguish the arc normally, and the arc will burn for a long time between the fractures, and there is a risk of explosion in severe cases.
Reasons for reduced vacuum degree:
1) There are hot spots at the connection between the glass (porcelain sleeve) and the metal
2) There are process problems in the assembly and commissioning of the vacuum bubble, which makes the vacuum bubble affected by mechanical external forces.
When doing preventive tests and regular maintenance of power equipment, the vacuum bubble must be tested for vacuum degree. In daily operation, the operator should inspect the metal shield of the vacuum bubble for discoloration, abnormal noise during operation, and keep records. When the vacuum degree decreases, the vacuum bubble must be replaced, strictly in accordance with the manufacturer's assembly process requirements, and the vacuum degree and mechanical properties test should be done, and the test results should be recorded for comparison during future maintenance and testing.
2. Handling methods for operating circuit failure phenomena
1) The fuse of the operating and signal circuits does not meet the requirements and blows, and should be replaced;
2) The voltage of the operating power supply is reduced, causing refusal to open or close. The cause of the power supply voltage reduction should be checked and analyzed, and the normal voltage should be restored;
3) The opening and closing coil is broken or short-circuited and burned, causing the circuit breaker to refuse to open or close. The unqualified opening and closing coils should be replaced as required;
4) The secondary circuit wiring is loose, broken or detached, and should be checked and replaced;
5) The energy storage motor cannot work normally, the energy storage motor is broken or short-circuited, and should be checked and replaced.
3. Troubleshooting of auxiliary switch and operating mechanism
1) The rotating arm and rotating connection of the auxiliary switch are loose or deformed (displaced), and should be adjusted.
2) The springs of various parts are aged or deformed, so that the rotating parts of various parts of the mechanism cannot be reset in time during the movement,it should be checked and replaced .
3) After the energy storage spring is completed, the energy storage motor cannot stop running. The reason is that the travel switch that disconnects the power supply of the energy storage motor is dislocated upward. If the travel switch is dislocated downward, the energy storage spring will not be completely pulled open, and the motor will stop running, so that the energy storage spring is not in place, causing the circuit breaker to refuse to open. The travel switch is in the right position, but the motor still cannot stop running. This is because the travel switch contacts are sticky or the spring (or spring) inside it is overheated and cannot be disconnected quickly, causing arcing between the contacts. If the fault cannot be eliminated after maintenance, the travel switch should be replaced or a capacitor should be connected in parallel between the two contacts (the capacitor plays an arc extinguishing role).
4) The buffer is deformed, loose or falls off, causing the circuit breaker to open past the dead point and causing the circuit breaker to refuse to close. The opening buffer should be adjusted or replaced.
5) The mechanical transmission part between the vacuum circuit breaker and the disconnector operating handle is deformed, so that the opening single axis cannot be restored normally, causing the circuit breaker to refuse to close.
6) The crank arm or shaft pin of the transmission part between the vacuum circuit breaker and the operating mechanism falls off or breaks, causing the mechanism to close while the circuit breaker is in the opening state, so that the mechanism and the circuit breaker cannot be linked normally. Press the opening button, turn the output shaft of the mechanism to restore it to the opening state, and then replace the shaft pin.
7) The energy storage motor runs normally, but the energy storage spring cannot be pulled open. This is because the clutch push wheel driven by the energy storage motor slips internally or the gear is broken. The clutch push wheel should be replaced.
4. Daily maintenance measures for circuit breakers
In the daily maintenance of vacuum circuit breakers, the transmission mechanism and insulating pillars of vacuum circuit breakers should be regularly inspected .
When the vacuum circuit breaker is regularly shut down for maintenance, the circuit resistance and mechanical properties test should also be performed to check whether the contact between the contacts and the conductive rod lead-out circuit is good (the oxide layer at the contact position should be processed when connecting the test line to avoid misjudgment) to avoid overheating and damage of the circuit breaker due to poor contact.
VTZ-12 vacuum circuit breaker (special model of Shaanxi West Power Tongzhong Electrical Co., Ltd.) is an indoor switchgear for rated voltage 12kV, AC 50/60Hz. It adopts a modular operating mechanism and is suitable for various industrial and mining enterprises, as well as power grid equipment. It can be used as a handcart unit for use with KYN28A-12 switchgear, or as a fixed unit with relevant mechanical interlocking, making it suitable for XGN2 and other fixed cabinets.
VTZ-12 vacuum circuit breaker has many advantages:
1.Performance of circuit breaker：
E2-C2-M2
2.Convenient maintenance:
the modular mechanism design allows for easy replacement of the closing and opening coils without the need for dismantling other components. This eliminates the need for testing or adjustment after replacement, ensuring users to replace them independently, making subsequent maintenance more convenient.
3.High conductivity performance:
the product features a well-designed conductive circuit that meets 1.1 times the rated current temperature rise level.
4.Wide application range:
the product series has a wide application range, rated currents from 630A to 5000A, and rated breaking currents from 20kA to 50kA. It is suitable for all environments within an altitude of 4500 meters and an operating temperatures from -40°C to 40°C.
5.Supports intelligent customization:
a. It can add a wireless temperature monitoring solution with self-powered design to ensure safety and maintenance-free operation.
b. It has a mechanical characteristics monitoring solution to provide real-time monitoring of circuit breaker operating data for early detection and resolution of potential problems.
c. It has a motorized cabinet entry solution to allow remote operation for ensuring personal safety.
d. Real-time component aging can be detected by partial discharge testing.
For more information about this product , please feel free to contact us as per following information:
Email: xdtz04@westpowerelectric.com
Website: https://www.xdtzelectrical.com/
Tel:+86 917 3661109
Mobilephone(whatsapp ): +86 18091765882
