What if the air pressure of the circuit breaker is low?

Anti-tripping plays a protective role, and relay control needs "locking" as a measure to prevent electrical misoperation. Our electrical operators are most afraid of misoperation, including: 1, closing the disconnector with load; 2. Close with grounding wire (grounding knife); 3, personnel into the charged interval; 4, wrong points, wrong circuit breaker; 5. Live grounding wire (grounding knife). And non-simultaneous juxtaposition. Among them, locking includes: mechanical locking is a locking mode in which the mechanical structure of switchgear operating mechanism restricts each other, thus realizing mutual interlocking. Electromagnetic lock is the auxiliary contact of circuit breaker, disconnector and circuit breaker door. Turn on or off the power supply of electromagnetic locks such as disconnectors and switchgear doors that need to be locked, so that their operating mechanisms cannot act, thus realizing the mutual locking between switching devices. The locking device is simple in principle and convenient to realize, and can lock different switch cabinets; It works well in a dry environment. However, due to our "national conditions", most of them are installed on indoor equipment of 35 kV and below. In use, due to various reasons, the auxiliary transfer switch can not be switched normally, the electromagnetic lock can not meet the sealing requirements, and it is corroded by moisture, which often leads to the lock failure. For outdoor high-voltage switchgear, electrical logic locking is often used to prevent false locking. The logical locking of the electrical circuit is to connect the auxiliary contacts of circuit breakers, disconnectors and other devices to the electrical operation circuits that need to be locked, such as disconnectors or grounding knife switches, so as to realize the mutual locking between the switching devices. Its characteristic is that the secondary circuit is complex and the workload of installation and maintenance is heavy. In order to eliminate the locking fault in time, the assistance or cooperation of maintenance comrades is often needed. The basic conditions for achieving this goal are electric equipment and mechanisms. At present, most outdoor switchgear of 330 kV and below adopt this kind of locking device, but the actual operation situation is far from the ideal goal. The main factors are poor sealing, corrosion and improper switching of auxiliary switch. Electrical locking, electromagnetic locking and mechanical locking frequently occur, and the switching operation is often forced to stop. Sometimes, the technical director has to ask for instructions to use the "master key" to forcibly unlock the operation or remove the locking device. In order to improve the difficult situation of anti-misoperation locking and the need of safe production, a microcomputer anti-misoperation locking system composed of host computer, computer key, electrical code lock and mechanical code lock has been applied and popularized. Microcomputer anti-misoperation locking system is to lock the circuit breaker, disconnector, grounding knife switch (grounding wire) and auxiliary contact of switch cabinet door (or combined with primary wiring simulation board) through microcomputer coding lock. Through the software system, the operating program (rule) or locking logic input program lock of the switch cabinet is switched, that is, the microcomputer five-prevention contact is added in the operating power circuit of the electric circuit breaker or the ground knife mechanism box, and the error prevention function is independently completed by the microcomputer five-prevention system. However, the microcomputer five-prevention system is required to have measures to prevent "idling (missing items in operation)". At present, the microcomputer lockout developed by a company in Zhuhai is widely used in China. In the process of use, the microcomputer anti-misoperation locking system is complicated in operation, slow in speed, difficult to install the coded lock, and individual accidents restrict its use and popularization. First of all, ensure that the circuit wiring is correct and the locking device works well at the same time; If the primary wiring of the equipment changes, or the circuit wiring changes in the same period, the phase should be timely or checked; Operators should be familiar with the synchronization point and synchronization circuit of the unit, and prevent two synchronization power switches from running in parallel at the same time; Manual synchronous operation should be identified at the same time to realize synchronous locking; It is forbidden to forcibly close the power connection line without the simultaneous confirmation or permission of the superior dispatcher.