Complete sets of switchgear with small structure and simple maintenance are widely used in 6kV~10kV medium voltage distribution systems in China. Now the number of complete sets of switchgear is increasing dramatically. Due to the compact structure of the complete set of switchgear, the space inside the switchgear is relatively small, and the production process and insulation level of the switchgear on the market are uneven at present. In addition, there are many outgoing lines of 6kV~10kV buses, frequent power cut and power transmission operations, high probability of line failure, impact on the operating environment and many other factors that are not conducive to the safety of the equipment, making the failure rate of the switchgear caused by arc short circuit very high.

The effective way to solve the arc hazard is to cut off the fault power supply at a fast speed. Install arc light protection device in the rectifier cabinet. When there is a small arc light in the cabinet, quickly cut off all operating rectifier units, so that faults can be found as early as possible, or limit the fault to a small range, so as to reduce losses as much as possible.

The arc light protection system can be tested after installation, and the arc light unit can be tested at the sensor with working light or flashlight. During the test, ensure the intensity of the working light. To test the whole device, only one channel needs to be tested, because each tripping and alarm circuit in the arc light unit is the same for each light input.

The use of arc light protection can not only quickly remove the arc light short circuit fault inside the switch cabinet, realize the rapid protection of medium and low voltage buses, but also improve the security and stability of the power system and equipment.