Reasons and preventive measures for the burning of the opening and closing coil of high voltage circuit breaker

The high-voltage circuit breaker is one of the main products of Henan Changzheng Electric Co., LTD. This paper mainly introduces the reasons and preventive measures of the high-voltage circuit breaker's opening coil and closing coil burning. High voltage circuit breaker is a kind of load switch, with short circuit and overload protection function, and its short circuit protection function is realized by electromagnetic coil. Because of its perfect protection function, easy maintenance and use, it is widely used in power system.

1. The reason why the switching coil is burned

Switch definition: switch from the close position to the sub position. It refers to the manual operation in the power system, the high-voltage circuit breaker from the closing position to the opening position.

1. Mechanical failure of switching electromagnet. The loose coil causes the electromagnet displacement when the circuit breaker is opened, and the core is jammed, causing the coil to burn; Or because of the short travel of the iron core, when the switching circuit power supply is switched on, the core top does not release the trip mechanism to make the coil energized for a long time and burn.

2, high voltage circuit breaker rejection. When the control circuit is normal, the failure of the high-voltage circuit breaker is the problem of the connecting rod, such as improper adjustment of the apex, so that the strength of the breaker opening iron core can not make the mechanism trip in time; Or because the protective locking mechanism does not act, resulting in the overload of the coil, resulting in the opening coil burned.

3. Improper adjustment of the stroke of the auxiliary switch opening state. When the circuit breaker is in the opening state, the auxiliary switch should be adjusted to make it within the travel range of the opening state. However, when adjusting the parameters of circuit breaker opening distance and overstroke, the initial state of circuit breaker opening is not adjusted accordingly, which will lead to the auxiliary switch can not switch the opening circuit normally, and the opening coil will be burned.

4. Improper use of auxiliary switch contacts in opening control loop. When the circuit breaker closing time is very short, far less than the circuit breaker opening time, the circuit breaker has been closed in place before the trip, and the delay effect of the delay contact will lose significance. On the contrary, in the opening process of the delay contact, due to the small insulation gap of the static contact of the auxiliary switch, the arc phenomenon often occurs, which will burn the contact of the auxiliary switch, and then cause the opening coil to burn.

5, protection control device failure. The opening command is issued by the protection control device, if the opening relay in the device is faulty, or the opening control loop auxiliary switch contact travel is large, resulting in the opening command can not exit in time, the opening coil will be charged for a long time and burned.