The selection principle of site distribution box.

When selecting the distribution box, we must follow the basic principles of reliability, simplicity and practicability from the perspective of cost and standardization. In addition, it should be noted that: 1) the technical parameters of the selected equipment must meet the requirements of reliability and protection level of equipment operation; 2) The selected equipment must meet the economic and practical requirements of the actual use process; 3) The operation process of the equipment is simple and safe; 4) The selected equipment should match other existing equipment.

Specific selection methods.

First of all, we should combine the existing website distribution box performance indicators and actual engineering factors, such as capital, installation conditions, analyze the distribution reliability evaluation, reliability as the center, under various conditions, the distribution cabinet, handcart cabinet parts and cars are reasonable, the operation and replacement operation is simple and feasible, it is safe and reliable, power off and maintenance, repair is convenient, etc; Secondly, determine the specific environment and space location of the installation, and make a comprehensive comparison and selection in the space size, economy, after-sales security and other aspects. The characteristics of domestic and imported equipment are shown in Table 1.

Then, from the later maintenance, operation failure rate, efficiency and other aspects, we actively use the equipment with simplified integrated intelligent protector type, and eliminate the control and protector type with high abnormal working rate based on complex relay.