1. Make clear the project positioning. The high-voltage switchgear is a complete set of combined products. At present, although there are hundreds of manufacturers in China, its core components are still mainly imported products. In case of technical problems, equipment maintenance and replacement are troublesome. Therefore, under the condition of sufficient budget, try to choose well-known brands because of their sufficient stock, The efficiency of solving problems is relatively high
2. Before purchasing the inspection qualification, ask the manufacturer for the factory test outline (or requirements) of the switchgear. Generally, regular manufacturers will have it. We should find out whether the main components are configured according to the drawing requirements and select the designated brands, such as Siemens, Schneider, etc
3. The cabinet body is made of high-quality steel plate, while the price of high-voltage switch cabinet is generally made of 300 high-quality steel plate
4. The arrangement of the whole group of cabinets, the arrangement order of the cabinet body and the position of the operation surface are the correct construction basis for the manufacturer to consider the problems such as making the partition plate, terminal guard plate and bus section support in the cabinet. The layout plan shall be consistent with the actual position of the incoming and outgoing lines on the site, especially the direction of the working surface of the cabinet, so that the high-voltage cabinet can be installed smoothly after it arrives at the site. It is often ignored at first. After the equipment arrives at the site, it is found that it does not meet the site requirements, and finally leads to rework
5. Incoming and outgoing line modes there are basically two connection modes for the conventional incoming and outgoing lines on the switch cabinet:
(1) Connection of incoming and outgoing cables and cable rooms
(2) The incoming and outgoing lines are led out by the wall bushing on the top of the cabinet and connected with the bus bridge, which is then connected with the overhead line through the wall bushing. There are also a few users. The cable rack is introduced from the top of the cabinet, connected inside the cabinet, connected on the top of the cabinet, and set up a safety net rack. The user provided a system diagram and standard scheme when ordering, but the way of incoming and outgoing lines cannot be fully expressed. The user should explain it in the technical agreement of the actual installation requirements on site, so it is difficult to install on site
6. The breaking capacity of the circuit breaker shall be correctly selected. On the primary system diagram, the selected circuit breaker indicates that the breaking capacity of the circuit breaker must be selected in addition to the model, rated working voltage and rated working current of the circuit breaker. There are user drawings and the breaking capacity of the circuit breaker is not selected, which makes it difficult for the manufacturer to carry out engineering design. The breaking capacity shall be selected according to the system short-circuit parameters. If the manufacturer does not understand the system short-circuit parameters, it is difficult to make a correct selection. There are also some user drawings that blindly select high breaking parameters without considering the system short-circuit parameters, resulting in unnecessary waste of funds. It is very important to correctly select the breaking capacity. We should not only ensure the safe operation, but also consider reducing the product cost