Analysis of common failure causes of low voltage switchgear

1. A short circuit occurs inside the switchgear.

1) The insulating base of the busbar support insulator or the plug-in contact is dirty, heavily wetted or mechanically damaged, causing a short circuit due to flashover or discharge. The cleaning should be strengthened, and the equipment should be replaced in time for the equipment to be damaged due to moisture.

2) Improper selection of electrical components, such as insufficient breaking capacity of the circuit breaker. The breaker with the right capacity should be selected.

3) Misuse. What often happens is the isolating switch with load operation. The operating procedures should be strictly implemented to prevent misuse.

4) The inspection tool is forgotten on the busbar. After the power failure overhaul, the maintenance tools such as the wrench and the screw driver were forgotten on the busbar due to negligence. The power supply was not carefully checked before the power transmission, and a short circuit occurred after the power transmission. Strictly in accordance with the requirements of the regulations, after the inspection, check the tools to prevent forgetting.

5) Small animals cause a short circuit. Short circuits are caused by small animals (such as mice, snakes, etc.) drilling into the switch cabinet. Install a protective net to prevent small animals from drilling in.

2. The busbar connection is overheated.

1) Poor contact. Measures such as transfer load, power failure overhaul or replacement of the busbar can be used.

2) The butt bolt is too tight or too loose. When tightening, the degree of tightness should be appropriate, generally tightened until the spring washer is flattened.