Shell protection level (IP code) of the technical content of the provisions of the mandatory, equipment shell quality standards must meet the design requirements and national, industry and other relevant standards. Equipment purchased before a serious review of the supplier's production and testing capabilities and test equipment, the supplier of similar goods must be provided through the national authority of the third-party shell protection level inspection agency testing and obtaining the relevant inspection or certification, so as to select the qualified equipment supplier. Before the equipment factory, in view of the construction site shell protection level inspection capacity is limited, you can organize the goods factory inspection, the incoming inspection pass forward. The test must be carried out in accordance with the provisions of our personnel to witness the confirmation of the station, only including the equipment shell protection level test, including all the test items can be qualified packaging factory.