According to the user, his house has only been renovated for two years. Recently, the air switch has been tripping. At first, it was the second trip. It was found that there was a leakage of the socket. After repairing it, it was the third trip. Push up forcibly. Sometimes it can be controlled for a few days, sometimes it can be controlled for tens of minutes, and sometimes the main brake will trip as soon as it is pushed up.
cause of issue:
The electrical appliances in the user's home are not very commonly used, because every day at work, basically one refrigerator uses electricity throughout the day. The figure shows the wiring schematic diagram of the distribution box of the user's home. Generally speaking, there are three possible reasons for the open air trip of household air.
(1) The reason for the line. Such as line aging, line leakage, etc.
(2) The cause of the load. Such as excessive electricity consumption at home.
(3) The reason for the air switch. For example, the quality of the air switch is not enough, and the contact is poor.
Combining the user's description of the fault, the user goes to work for a long time during the day, and the doors and windows at home are often closed. In the rainy season, the air in the house is too humid. If the quality of the wires is not good enough, or the connection between the air switch and the circuit is poor, it may cause the above failure.
After the power failure, the insulation resistance of the indoor circuit was measured with a megohmmeter, and it was found that the resistance value was 0.3MΩ, which obviously did not meet the requirements. What kind of line segment is poorly insulated? The next step is to measure by the segmented detection method, and it is found that the insulation resistance of bedroom 2 is very small. Further inspection, it turned out that the wire at the bedside switch in the bedroom was broken, and the fault was eliminated after insulation treatment.