What maintenance matters need to be paid attention to during the use of switchgear?

The following maintenance items are required for switchgear during use:

Regularly check the appearance

Cleaning the surface of the equipment: Dust, oil and other pollutants may affect the heat dissipation and insulation performance of the switchgear. The surface of the equipment should be wiped regularly with a clean, dry soft cloth. For stains that are difficult to remove, a mild detergent can be used, but the detergent should be prevented from entering the interior of the equipment. For example, in a factory environment, dust is easily accumulated on the surface of the switch cabinet, and regular cleaning can effectively prevent dust from entering the internal circuit.

Check the integrity of the equipment casing: Check whether the casing has cracks, deformation or signs of damage. If the casing is damaged, moisture and foreign matter may enter the interior of the equipment, causing electrical failures. At the same time, check whether the mounting screws of the equipment are loose. If they are loose, tighten them in time to ensure the mechanical stability of the equipment.

Check the electrical connection part

Tighten the connection bolts: The bolts of electrical connection parts such as terminal blocks may loosen due to vibration during equipment operation. Regularly use appropriate tools to check and tighten the connection bolts to ensure good electrical connections. Loose connections increase contact resistance, causing local overheating, and in severe cases, may cause fires.

Check the contact point condition: Check whether the contact point is oxidized, ablated or worn. The oxide layer increases the contact resistance and affects the conductivity. For slightly oxidized contact points, professional electrical contact cleaners can be used for cleaning; if the ablation or wear is severe, the contact parts need to be replaced.

Check the operating mechanism

Check the operating flexibility: Operate the operating mechanism of the switchgear regularly to check whether its movement is flexible and smooth. For manually operated disconnectors and other equipment, the operating handle should be able to easily open and close the switch; for electrically operated circuit breakers and other equipment, check whether the motor and transmission parts of the electric operating mechanism are working properly. If the operating mechanism is stuck, the cause of the fault should be promptly checked. It may be caused by rusting of mechanical parts, poor lubrication, or foreign matter entering.

Check the interlocking device: Many switchgear are equipped with interlocking devices to prevent misoperation. Check whether the interlocking device is working properly to ensure that the operation can only be performed when safety conditions are met. For example, the interlock between the circuit breaker and the disconnector should ensure that the disconnector can only be operated after the circuit breaker is disconnected to prevent dangerous operations such as pulling and closing the disconnector under load.

Check the arc extinguishing device (applicable to switchgear with arc extinguishing function)

Check the condition of the arc extinguishing chamber: For circuit breakers, load switches and other equipment with arc extinguishing function, check whether there are foreign objects, damage or traces of arc burning inside the arc extinguishing chamber. The normal operation of the arc extinguishing chamber is essential for extinguishing the arc when the circuit is cut off. If there is a problem with the arc extinguishing chamber, it should be replaced or repaired in time to avoid affecting the arc extinguishing ability of the equipment and causing the fault to expand.

Check the state of the arc extinguishing medium: For example, for SF6 (sulfur hexafluoride) switchgear, the pressure of SF6 gas should be checked regularly. Insufficient SF6 gas pressure will affect the arc extinguishing performance, and gas needs to be replenished in time. At the same time, check whether the gas is leaking, and a professional SF6 gas leak detector can be used for detection.

Insulation performance inspection

Measure insulation resistance: Use an insulation resistance tester to regularly measure the insulation resistance of the switchgear, including phase-to-phase insulation and relative insulation to ground. The insulation resistance value should meet the technical requirements of the equipment. If the insulation resistance is too low, it may indicate that the insulation parts of the equipment are aging, damp, and other problems, which require further inspection and treatment.

Check the status of insulating parts: Check whether the insulating parts such as insulators and insulating sleeves have cracks, damage or signs of surface discharge. These insulating parts are very important to ensure the electrical safety of the equipment and should be replaced in time if any problems are found.

Functional test

Opening and closing time test: For key switching equipment such as circuit breakers, regularly test their opening and closing time. Failure of the opening and closing time to meet the requirements may affect the protection performance of the power system. For example, a long opening time of the circuit breaker may cause greater damage to the equipment due to fault current.

Protection function test: Check whether the protection functions of the switchgear, such as overload protection and short-circuit protection, are normal. The protection action of the equipment can be tested to be accurate and timely by simulating fault conditions such as overload and short circuit.