First, the vacuum bubble is reduced 1.1 Fault phenomenon The vacuum circuit breaker breaks the current in the vacuum bubble and extinguishes the arc. The vacuum circuit breaker itself has no means for qualitatively and quantitatively monitoring the vacuum degree. Therefore, the vacuum degree reduction fault is a hidden fault, and the degree of danger is far greater than Dominant failure. 2.1 Fault Symptoms The following faults exist depending on the cause of the fault: 3.1 Fault phenomenon (1) The opening operation cannot be realized after closing; 4.1 Symptom This fault is a recessive fault and must be measured by the characteristic tester to obtain the relevant data. Wenzhou Celecare Medical Instruments Co.,Ltd , https://www.wzcelecare.com
1.2 Analysis of the causes The main reasons for the reduction in vacuum are as follows:
(1) There is a problem with the material or manufacturing process of the vacuum bubble, and there are tiny leak points in the vacuum bubble itself;
(2) There is a problem in the material or manufacturing process of the corrugated tube inside the vacuum bubble, and a leak occurs after multiple operations;
(3) Split type vacuum circuit breaker, such as the vacuum circuit breaker using electromagnetic operating mechanism, in operation, because the distance of the operating link is relatively large, it directly affects the characteristics of the switch's synchronization, bounce, overtravel, etc., so that the vacuum degree is lowered. The speed is speeding up.
1.3 Fault Hazard The reduction in vacuum will seriously affect the ability of the vacuum circuit breaker to open and over-current, and cause the life of the circuit breaker to drop sharply.
1.4 Treatment method (1) When performing periodic power failure maintenance of the circuit breaker, the vacuum tester must be used to test the vacuum degree of the vacuum bubble to ensure that the vacuum bubble has a certain degree of vacuum;
(2) When the vacuum is reduced, the vacuum bubble must be replaced, and the characteristics test such as stroke, synchronization, and bounce must be performed.
1.5 Precautionary measures (1) When vacuum circuit breakers are used, mature products produced by reputable manufacturers must be selected;
(2) Select a vacuum circuit breaker with a body and an operating mechanism;
(3) When the operation personnel patrol, it should be noted whether there is a discharge phenomenon outside the vacuum bubble of the circuit breaker. If there is a discharge phenomenon, the vacuum degree test result of the vacuum bubble is basically unqualified, and the power should be replaced in time;
(4) When the maintenance personnel perform power failure maintenance work, they must perform characteristic tests such as synchronization, bounce, stroke, and overtravel to ensure that the circuit breaker is in good working condition.
Second, the vacuum circuit breaker broke down
(1) The remote remote control of the circuit breaker can not be separated;
(2) The manual manual opening can not be divided;
(3) The relay protection action during the accident, but the circuit breaker cannot be separated.
2.2 Analysis of the cause (1) Broken line of the opening operation circuit;
(2) Broken wire of the opening brake;
(3) The operating power supply voltage is reduced;
(4) The resistance of the opening coil is increased, and the breaking force is reduced;
(5) Deformation of the ejector lever, there is a jam phenomenon when the brake is opened, and the breaking force is reduced;
(6) The ejector lever is severely deformed and is stuck when it is opened.
2.3 Fault Hazard If the failure of the trip occurs in an accident, it will lead to an escalation of the accident and expand the scope of the accident.
2.4 Treatment method (1) Check if the opening circuit is broken;
(2) Check if the opening coil is broken;
(3) Measure whether the resistance value of the opening coil is qualified;
(4) Check if the opening ram is deformed;
(5) Check if the operating voltage is normal;
(6) Change the copper ram top rod to steel to avoid deformation.
2.5 Precautionary measures If the operating personnel find that the opening and closing indicator light is not bright, it should promptly check whether the opening and closing circuit is disconnected; the maintenance personnel should pay attention to measuring the resistance of the opening coil when checking the power failure, and check whether the opening ram is deformed; The material of the opening ram is copper and should be replaced with steel; low voltage switching test must be carried out to ensure reliable circuit breaker performance.
Third, the spring operating mechanism closes the energy storage circuit failure
(2) The operation of the energy storage motor does not stop, and even the motor coil is overheated and damaged.
3.2 Reason analysis (1) The installation position of the stroke switch is lower, so that the closing spring has not been stored yet, the contact switch contact has been converted, the motor power is cut off, and the stored energy of the spring is not enough to open the gate;
(2) The installation position of the travel switch is on the upper side, so that after the energy storage of the closing spring is completed, the contact switch contact has not been converted, and the energy storage motor is still in working state;
(3) The travel switch is damaged and the energy storage motor cannot be stopped.
3.3 Fault Hazard If the accidental storage energy is not in place, if the line has an accident and the circuit breaker refuses to open, the accident will be overstepped and the scope of the accident will be expanded. If the energy storage motor is damaged, the vacuum switch cannot be opened and closed. .
3.4 Treatment method (1) Adjust the position of the stroke switch to achieve accurate motor power off;
(2) If the travel switch is damaged, it should be replaced in time.
3.5 Precautionary measures During the switching operation, the operating personnel should pay attention to observe the closing energy storage indicator to judge the energy storage capacity of the closing; after the maintenance work is completed, the maintenance personnel should perform 2 closing operations on the spot to determine The circuit breaker is in good condition.
Fourth, different periods of closing and closing, large bounce value
4.2 Analysis of the reasons (1) The mechanical performance of the circuit breaker body is poor. After multiple operations, due to mechanical reasons, the value of the bounce is too large;
(2) Split-type circuit breakers Because of the large distance of the operating rod, when the breaking force is transmitted to the contacts, there is a deviation between the phases, resulting in a large value in different periods and bounce.
4.3 Fault Hazard If the period is different or the bounce is large, it will seriously affect the ability of the vacuum circuit breaker to open and over-current, affecting the life of the circuit breaker, and causing the circuit breaker to explode in severe cases. Since this fault is a hidden fault, it is more dangerous.
4.4 Treatment method (1) Under the premise of ensuring the stroke and overtravel, the synchronization and bounce test data are within the qualified range by adjusting the length of the three-phase insulated tie rod;
(2) If it cannot be achieved by adjustment, the vacuum bubble of the data failure phase must be replaced and re-adjusted until the data is qualified.
4.5 Precautionary measures Because there are many hidden troubles in the split type vacuum circuit breaker, the integrated vacuum circuit breaker should be used when replacing the circuit breaker; the characteristic tester must be used for the characteristic test during the regular maintenance work, and the problem can be solved in time.