Introduction to Matters Needing Attention in the Use of Pole-mounted Circuit Breakers

A pole-mounted circuit breaker is a circuit breaker that is installed and operated on a pole. The strength research level and manufacturing technology of various circuit breakers have made great progress. Vacuum circuit breakers are not limited to medium-voltage power grids, but are developing towards high voltage and large capacity. Sulfur hexafluoride circuit breakers have many Advantages, such as strong opening capacity, many continuous breaking times, frequent operation, low operating noise, no fire hazard, etc., it is a very good oil-free equipment.

1. Brief introduction of pole-mounted circuit breaker

With the rapid development of my country's economy and the continuous increase of power supply, especially the increasing dependence of various customers on power, in order to improve the power supply reliability of the power grid, the pole-mounted circuit breaker is often used in the connection, segmentation, In order to improve the power supply reliability of the power grid, the management of the pole-mounted circuit breaker is a weak link of the county-level power supply enterprises. Only when it is included in the standardized and institutionalized management can it play its due role, otherwise it will directly It affects the security management and power supply reliability of the enterprise. The management of pole-mounted circuit breakers should be checked from the beginning of design, and the pole-mounted circuit breakers on each line should be distributed step by step in a step-by-step manner to avoid skipping trips caused by faults at the end of the line. The safe and reliable operation of the equipment must be ensured during the installation process. The unified command of dispatch must be included in the operation management to avoid the harm caused by private operation. During the operation, the relevant procedures should be completed according to the regulations. The dispatcher will give the order to the person in charge of the work, and the person in charge will arrange the staff to operate the switch on the pole, and operate according to the operation ticket. "Someone is working on the line, it is forbidden to close the gate" warning sign. The naming, naming and numbering of the pole-mounted circuit breaker shall be carried out by the operation management unit, and shall be reported to the communication center, the operation and maintenance department, the safety supervision department and other units after being summarized by the competent department for filing.

The management system is issued from the company level, and the design and installation, operation management, inspection and assessment of the pole-mounted circuit breaker are clearly specified in the system.

2. Arrival acceptance of pole-mounted circuit breaker

After the equipment is delivered, the appearance inspection should be carried out first; whether the vacuum interrupter has air leakage, rupture, and no oxidation inside the interrupter; whether the model of the operating mechanism is consistent with the design model of the circuit breaker; Consistent, whether the packing list corresponds to the real thing. The vacuum interrupter is the core component of the circuit breaker. Its vacuum degree is the performance sign of whether the switch is normally opened, closed and arc-extinguished. The reduction of the vacuum degree will directly affect the interrupting ability of the circuit breaker. The device is tested.

3. Design and installation of pole-mounted circuit breaker

3.1 When installing pole-mounted circuit breakers on 10kV public lines, the operation and maintenance department, management unit, safety supervision department, and communication center should jointly investigate and formulate the installation location on the spot. The installation location should be selected reasonably. Larger branch lines to ensure that when a fault occurs in a certain area, the area will be cut off to ensure the safe and reliable operation of the large-area power grid. The management unit is not allowed to install it without permission.

3.2 When new users or customers need to install pole-mounted circuit breakers, the customer center should seek opinions from the operation and maintenance department, line supervisory unit, safety supervision department, and communication center. The designed interrupting capacity of the pole-mounted circuit breaker should meet the standard of the interrupting capacity of the customer's equipment to ensure the safe and reliable operation of the power grid. It is strictly forbidden to design a capacity that is too large, so as to avoid the circuit breaker from skipping tripping and affecting the safety of the line. , Reliable operation.

3.3 Relevant tests should be carried out before the installation of the pole-mounted circuit breaker, and the installation can only be allowed after passing the test.

3.4 When installing the pole-mounted circuit breaker, it should be hoisted or bench-mounted according to the environment. It is best to use a bench-mounted installation to facilitate the installation of isolation switches, lightning arresters and grounding devices, and it is also convenient for future operation and maintenance.

4. Operation management of pole-mounted circuit breaker

4.1 The pole-mounted circuit breaker of 10KV lines shall be uniformly dispatched by the dispatching center, and any unit or individual is not allowed to close the pole-mounted switch without permission. Those who pull and close the switch on the pole without the permission of the dispatcher shall be punished by the management unit and individual according to the management method once found.

4.2 If it is necessary to stop the switch on the 10KV line column due to line maintenance or business expansion project, the responsible unit or construction unit shall apply for the first type of line work ticket. The person in charge of the work will send the completed work ticket to the communication center one day before the start of work, and the dispatching operation management personnel will review the work ticket and confirm that the safety measures are complete and the ticket is qualified before going through the registration procedures for the work ticket.

4.3 The operating unit can operate the pole-mounted circuit breaker with the permission of the dispatcher with the work ticket. During the operation, the operation ticket should be handled and used according to the regulations, and the repeat system should be implemented. After the operation, it should be hung on the pole where the circuit breaker on the pole is located. There is a warning sign saying "someone is working on the line, it is forbidden to close the gate", and special personnel are assigned to guard it at the same time.

4.4 After a line failure occurs, when it is necessary to stop the circuit breaker on the column for emergency repair, the emergency repair unit must report to the dispatcher and handle the corresponding emergency repair form. On the electric pole where the upper circuit breaker is located, a warning sign is hung on the pole that says "someone is working on the line, it is forbidden to close the switch", and special personnel are assigned to guard it at the same time.

4.5 When the circuit breaker on the pole trips due to a fault, the management unit shall report to the dispatching center. The report includes the location, serial number, power outage area, and cause of the power outage of the pole-mounted circuit breaker. After the line fault is eliminated, the management unit will report to the dispatching department, and the power transmission can only be carried out after the dispatching agrees.

4.6 The registration, naming and numbering of the circuit breaker on the column shall be carried out by the operation and maintenance management unit. The quality department records, and the specific information includes the serial number, name, manufacturer, breaking capacity, location, factory date, and installation time of the pole-mounted circuit breaker.

4.7 Operation and maintenance. For the operation and maintenance of the pole-mounted circuit breaker, the maintenance work should be carried out in the preventive time of the substation every spring. The maintenance content mainly includes checking whether the incoming and outgoing lines and equipment clamps are abnormal and need to be replaced, and whether the mechanical mechanism is running properly. Jamming phenomenon, whether the action is sensitive, whether the setting value meets the operation requirements, whether the air pressure value and insulation value are normal, etc., to ensure the safe, reliable operation and sensitive action of the circuit breaker.

4.8 The setting value of the circuit breaker on the column should be adjusted according to the load conditions to prevent frequent power outages or skipping trips caused by the setting value. After the setting changes, the management department should promptly inform the operation and maintenance department, the communication center, and the safety supervision department.

4.9 The damaged or replaced pole-mounted circuit breaker shall be handed over to the material company by the original management department, and the material company shall contact the manufacturer for maintenance and then use it again.

5. Matters needing attention in the use of pole-mounted circuit breakers

5.1 If it is necessary to contact the circuit breaker for operation and maintenance, the circuit breaker must be disconnected, and the main circuit and control circuit should also be disconnected, and the main circuit should be reliably grounded.

5.2 If the energy storage spring operating mechanism is used, the closing spring must be released before maintenance.

5.3 Loose bolts and nuts should be fully tightened. Spare parts such as spring shrapnel should not be used after use.

6. Evaluation and Improvement of pole-mounted circuit breaker

The strength research level and manufacturing technology of various circuit breakers have made great progress. Vacuum circuit breakers are not limited to medium-voltage power grids, but are developing towards high voltage and large capacity. Sulfur hexafluoride circuit breakers have many Advantages, such as strong opening capacity, many continuous breaking times, frequent operation, low operating noise, no fire hazard, etc., it is a very good oil-free equipment. However, sulfur hexafluoride has high requirements on processing technology, materials, and operating environment, and the product price is high; the requirements for anti-leakage gas are high, and a series of auxiliary gas supply measures are required; the possibility of explosion cannot be completely ruled out; The products produced by low-chlorine compounds are highly toxic, threatening personal safety, and easily causing environmental pollution. The large temperature difference between summer and winter in our area has a great impact on the performance of sulfur hexafluoride circuit breakers. The vacuum circuit breaker adopts vacuum technology, has no pollution and no harm to human body and nature, and its performance meets the requirements of power switching equipment. It is one of the better equipment worthy of popularization and application in power applications. As a column-mounted switch, it has the characteristics of large quantity, scattered locations, complex operating environment, frequent operation, and large maintenance. It is a better choice to choose a vacuum circuit breaker. However, the operation, maintenance and management of pole-mounted circuit breaker must be managed from content to dispatch to ensure the safety of operation and maintenance personnel and equipment, and to prevent various accidents caused by inadequate management.