Circuit breakers are the main electrical devices that turn on and off the circuit. Because of its frequent operation, some faults often occur. For example, the circuit breaker cannot be closed or the circuit breaker cannot be opened. The circuit breaker is not automatically opened or closed automatically. The circuit breaker is deficient in oil or carbonized, the circuit breaker operates in abnormal energy, and even a circuit breaker may catch fire or explode. The major accident. And so on.
1. The remote operation of the high voltage circuit breaker cannot be closed
The remote operation of the high-voltage circuit breaker cannot be closed, which is one of the frequent faults of the circuit breaker. The improper handling of the on-duty personnel often delays the delivery time of the equipment. Therefore, when this type of failure occurs, the cause of the failure should be determined based on the abnormality in the operation process and the necessary troubleshooting work should be carried out. Because of the different types of circuit breakers, the troubleshooting methods are also different. Here, only the general processing methods are introduced.
First, determine the cause of the fault according to whether the red and green signals are normal during operation. When operating before or after operation. When the red and green lights are not on, it can be judged that the power is lost. Check and replace the operating fuse at this time. When the green light is on before and after the operation, and the control switch is in the closed position, the red light is off and the current is not indicated (assuming that the power transmission line is loaded with the brake). Then the action of the closing relay should be observed on the spot: when closing When the relay is not operating, it is a fault in the operating circuit; when the closing relay is in operation and cannot be closed, it is a fault in the closing circuit or a fault in the mechanical part, and the difference should be handled. Circuit breakers for hydraulic units. Check that the hydraulic pressure is normal. For air circuit breakers, check that the compressed air pressure meets the specified value. If the person on duty is unable to handle it, he should promptly notify the person in charge of the repair.
2, high-voltage circuit breaker can not be opened
High-voltage circuit breakers cannot be opened at a remote location, which is a great danger to safe operation. When a device fails, the circuit breaker installed in the circuit of the device cannot be opened, which will cause the upper circuit breaker to automatically trip, thereby expanding the scope of accidental power outage. The reason why a high-voltage circuit breaker cannot be opened at a remote location is generally due to a malfunction of the mechanical part of the operating mechanism, and the absence of a voltage in the operating circuit or a broken line in the opening circuit. The latter reason may be found during operation. For example, when the red light of the circuit breaker is not on during operation, the person on duty should first check whether the signal light is good. Then check whether the operation fuse is blown. If it is blown, it should be replaced immediately: If it is not blown, the possibility of disconnection in the sub-gate circuit should be considered. When it is found that the high-voltage circuit breaker cannot be remotely opened, the on-duty personnel shall follow the following principles as soon as possible:
1) During normal operating hours
According to whether the red signal light is normal or not, it is judged whether the operation power is disappeared. If the red light does not light, the operating fuse should be replaced quickly, and then the opening operation should be performed. On-duty personnel may be able to open the gate one person at a distance, the other distance), to judge whether it is a failure of the operation loop or the failure of the mechanism itself.
If the gate core is normal but the circuit breaker cannot be opened, it is an anti-card mechanism.
(Air circuit breaker pressure must be normal).
2) At the time of opening in an accident
– The person observes the operation of the split iron core on site (note that if the iron core of the safety gate does not move, the operating circuit shall be checked: if the circuit breaker can be interrupted by a mechanical breaking device at this moment
If emergency interrupting is required, if the relay protection device is operated or the manual remote pull can not be opened, and the main equipment may be seriously damaged, the upper circuit breaker shall be manually opened immediately and then the circuit breaker shall be blocked at the fault circuit breaker. breaker. If the mechanical opening device cannot open the circuit breaker, quickly open the isolation switch on both sides of the circuit breaker and restore the power supply to the previous stage. After that, find out the cause of the malfunction and proceed. In the event of an accident, if time permits, the on-duty personnel should quickly go to the fault circuit breaker and open the circuit breaker with a mechanical opening device. If the mechanical opening device cannot be used, the operating mode should be switched immediately.
3, due to failure of the circuit breaker is not allowed to split it
When the circuit breaker in operation finds one of the following faults, it is prohibited to disconnect it. 7 The oil circuit breaker has no oil or is seriously deficient in oil; 7 The oil circuit breaker is carbonized; 7SNl, sN2 and other types of low oil circuit breakers break the two-phase insulating rods. :
1. The arc extinguishing chamber of the circuit breaker is broken or the contacts are melted;
2. The air circuit breaker compressed air pressure is too low and cannot be maintained to prevent explosion accidents.
3. Circuit breakers with hydraulic construction, when the hydraulic pressure is reduced to zero (refers to hydraulic systems that do not prevent slow-interval measures).
If the above-mentioned phenomenon is observed by the on-duty personnel, it should be considered that the circuit breaker cannot be opened safely, and the operating fuse of the circuit breaker shall be immediately removed. In this way, it is impossible for the remote to separate the circuit breakers, and even if the equipment provided by the circuit breaker fails, the protection device will not be caused to move. At the same time, on-duty personnel should hang a “Prohibit Operation” warning sign on the mechanical trip device or on the operation box. For the hydraulic mechanism that has not taken measures against slow opening and closing, measures should be taken to prevent the circuit breaker from opening automatically and slowly, and then the following principles should be followed: