Malfunction and solution of air circuit breaker

Promulgator : TAIXIDate : 2018-10-25Views : 99

Air circuit breakers are often referred to as frame breakers because they are wrapped in a frame, which is still common. When the main contact is not closed or closed, the air circuit breaker will cause some unnecessary harm. There are several possible reasons for this study:

(1) Due to the high current caused by the release of the energy coil, the overheating of the coil results in unstable work.
(2) Because of the long-term high voltage of the relay, the contact surface is oxidized, the contact resistance becomes larger, and the contact can not be connected normally.
(3) Because the stator and rotor of the motor are inconsistent, they friction with each other, resulting in a large amount of heat, resulting in motor speed instability, or even stop, resulting in the ACB circuit breaker can not work properly. Generally speaking, for the above phenomenon, the common solution is: the relay contact is oxidized, it can be removed from the relay, each contact point will be lit with sandpaper. After reinstallation, the ACB circuit breaker is in steady state. The rotor bearing is inclined if there is friction between the rotor and the stator. Bearings should move to the right. After fixing, the upper part of the machine will be tested and all will return to normal.

Then the common failures and solutions of the tripping device are discussed. Due to improper operation of electrical equipment under low voltage conditions, general circuit breakers are usually equipped with a low voltage release device (called release device) to protect. When the line is in voltage or tripod fault, the circuit breaker can not work normally. The main analysis is as follows:

1. Failure caused by power quality

In the existing air circuit breaker, the low-voltage tripping device is mainly controlled by electronic circuit, because of the increase of auxiliary function, it becomes more and more complex. However, there are many harmonics in the domestic power grid. These harmonics will be connected with the main circuit of the control circuit of the voltage tripping circuit under the overheated capacitor to make it invalid, thus affecting the use of the whole ACB circuit breaker.

2. Structural design defects cause release failure.
The low-voltage tricycle includes at least a moving, static core and coil, as well as the electronic wiring part of the trip. In China, the first and second generations of general circuit breakers adopt direct power control to suck under the voltage tripping structure. Serious environmental pollution will lead to static iron core and unreliable when operating or helping to absorb thrust structure, and AC noise will appear during operation. In this case, the coil current will increase and the core will increase, causing the coil to burn.

3. Low voltage tripping failures due to defects in manufacturing processes.
Quality is produced, there is no first-class manufacturing process, only design is not good, there are many problems in manufacturing, such as:

(1) The grinding of static core will cause communication noise and burn the coil.
(2) Excessive shrinkage of winding will affect inter turn insulation.
(3) No immersion process after winding, which can prevent rotation.
(4) The conductor of the coil is not welded to the conductor and will fail after a certain period of operation.
(5) The electronic components of electronic components must undergo rigorous and aging inspection, which will lead to the failure of the components after a certain operating time, thus causing damage to the release device.

The common faults of these air circuit breaker should be noted and various methods should be actively considered to ensure the long-term use of circuit breakers.