Manual Closing Device in High-Voltage Power Distribution Cabinets

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### Key Points of Operation and Maintenance

- **Routine Inspection**: Regularly inspect the substation, check whether the appearance, indicator lights, instruments, etc. of the HXGN-12 high-voltage switchgear are normal, and whether there are abnormal situations such as strange smells and noises; check whether the oil temperature, oil level, and sound of the transformer are normal; check whether the cable joints are overheated or loose, etc.

- **Regular Maintenance**: Conduct regular maintenance on the HXGN-12 high-voltage switchgear, including cleaning the cabinet body, checking whether the connections of electrical components are loose, replacing aging components, etc.; conduct regular maintenance on the transformer, including taking oil samples for testing, checking whether the core grounding is good, and carrying out preventive tests, etc.

- **Fault Handling**: When a fault occurs in the substation, it should be dealt with in a timely manner. First, it is necessary to judge the approximate location and cause of the fault according to the fault phenomenon and alarm information, and then take corresponding measures to repair it.

### Advantages and Disadvantages

- **Advantages**: The HXGN-12 high-voltage switchgear has the characteristics of small size and compact structure, which can effectively save the floor area of the substation. It adopts a metal-enclosed structure with a high protection level, which can effectively prevent personnel from misoperating and the impact of the external environment on the equipment. The layout of internal electrical components is reasonable, with good insulation performance and high reliability.

- **Disadvantages**: The rated current and short-circuit breaking current of the HXGN-12 high-voltage switchgear are relatively limited, and it may not be very suitable for application scenarios with large capacity and high short-circuit current. It has certain requirements for the temperature, humidity and other conditions of the operating environment. In harsh environments, special protective measures may need to be taken. The price of the equipment is relatively high, and professional technicians and equipment are required for later maintenance, and the maintenance cost is also relatively high.

## Basic Principle Through manual operation of the mechanical structure, the moving contact and the stationary contact of the circuit breaker are closed, thus realizing the connection of the electrical circuit. During the operation, the external force applied by the operator is transmitted to the closing mechanism of the circuit breaker through a series of transmission mechanisms, driving the moving contact to move towards the stationary contact and finally completing the closing action.

### Structural Components

- **Operating Handle**: It is a component for the operator to manually apply external force. It is usually designed in a shape that is easy to hold and operate and is located on the front panel or side of the power distribution cabinet, facilitating operation by personnel in emergency situations or during maintenance.

- **Transmission Mechanism**: It is a component that transmits the external force of the operating handle to the closing mechanism of the circuit breaker. Common transmission methods include connecting rod transmission, gear transmission, etc., ensuring that the external force can be accurately and effectively transmitted to make the contacts of the circuit breaker close reliably.

- **Closing Locking Mechanism**: It is a component used to prevent misoperation and ensure the safety of operation, such as locking electromagnets, mechanical locking devices, etc. The closing operation can only be unlocked when certain conditions are met, for example, when the circuit breaker is in the open state and the grounding switch is in the open position.

- **Position Indication Device**: It is a component used to display the current state of the closing device, usually including closing indicator lights, opening indicator lights, etc. Operators can intuitively understand whether the closing operation is successful and the operating state of the equipment by observing the state of the indicator lights.

### Operation Process 1. **Preparatory Work**: Before performing the manual closing operation, operators need to wear appropriate insulating protective articles, such as insulating gloves and insulating shoes, and ensure that the surrounding environment is safe without leakage, short circuit and other dangerous situations. Meanwhile, check whether various parameters of the high-voltage power distribution cabinet are normal, such as voltage and current.

2. **Unlocking Operation**: If the closing device is equipped with a locking mechanism, it is necessary to unlock it first. For example, for the locking electromagnet, it is necessary to check whether it is working normally. After meeting the unlocking conditions, unlock the locking device through corresponding operations.

3. **Manual Closing**: The operator grasps the operating handle and slowly and steadily pushes the handle in accordance with the specified operation direction and force. Through the transmission mechanism, the external force is transmitted to the closing mechanism of the circuit breaker, making the moving contact and the stationary contact of the circuit breaker gradually close. During the closing process, pay attention to observing the state of the closing device and the response of the equipment. If there is any abnormality, stop the operation immediately.

4. **Confirmation of Closing**: After the closing operation is completed, observe the position indication device to confirm that the closing indicator light is on. Meanwhile, check whether the instruments, relays and other equipment on the power distribution cabinet are working normally to ensure the success of the closing operation.

### Precautions - **Safety Protection**: Operators must strictly abide by the safety operation procedures, correctly wear insulating protective articles to avoid the occurrence of electric shock accidents. During the operation process, keep a safe distance from the high-voltage live parts to prevent accidental electric shock.

- **Prevention of Misoperation**: Manual closing devices are usually equipped with locking mechanisms to prevent misoperation. Operators must ensure that the locking mechanism has been unlocked before the operation and strictly follow the operation process during the operation to avoid equipment damage or casualties caused by incorrect closing.

- **Equipment Inspection**: Before and after the operation, conduct a comprehensive inspection of the high-voltage power distribution cabinet and the manual closing device, including the appearance of the equipment, connecting parts, indicator lights, instruments, etc., to ensure the normal operation of the equipment. If any abnormality is found in the equipment, report it in time and carry out maintenance and treatment.