Because of its excellent product performance, industrial plugs are widely used in various mining enterprises such as petrochemical industry, hotels, iron and steel smelting, shopping malls, electric power, docks, electronics, ports, railways, water treatment, construction sites, mining areas and airports. Industrial plugs are suitable for industrial use, and are generally divided into 3-core, 4-core, 5-core, etc. The current is generally divided into 16A, 32A, 63A, 125A, 250A, 420A, etc., and the protection level can be divided into IP44 and IP67, which are relatively conventional. Generally, it is used together with industrial sockets and connectors. NEMA wiring device must be as small as possible in order to realize frequent commutation, but also to realize braking during commutation and acceleration after commutation. Therefore, it is necessary to adopt rapid commutation device and smart braking device. IP54, i.e. dust prevention is level 5: dust intrusion cannot be completely prevented, but the amount of dust intrusion will not affect the normal operation of the product; Waterproof grade is Grade 4: prevent splashing water from intruding and prevent splashing water from all directions from intruding. As a new type of power supply and inspection accessories imported from abroad. In China, it has rapidly risen and been used in a large number of projects. Here, we introduce the practical application of industrial plugs in port terminals.I. Requirements for the use of electrical appliances in ports and terminals.Because the port or wharf is located at the seaside, it is necessary to consider the waterproof performance of power plug-in, as well as the international specialization of container transportation tools, the convenience of using power for equipment maintenance instruments and the mobility of temporary loading and unloading equipment.1. overhaul of wharf facilities and equipment.The wharf covers a large area and is used for the transshipment and stacking of goods. There are various handling equipment, such as cranes, large gantry cranes, conveyor belts, conveyors, etc. These machines need regular maintenance. In order to facilitate the maintenance of the equipment, it is necessary to equip the power socket beside the equipment. In this way, all kinds of maintenance equipment can be plugged in directly when in use.2. Marine container power supply.Port power supply and other facilities must be matched with international general shipping equipment. For example, in order to keep the low temperature in the container during transshipment at the wharf, reefer container needs to continue to plug in the power supply at the wharf. Therefore, the port must be equipped with sockets matched with containers.3. Power supply for terminal mobile equipment.There are many electric equipments on the wharf that need to be moved and used. Using plug-in power supply can make the operation and use of scraper conveyor and its auxiliary facilities more convenient.2 Power plug equipment types for ports and docks.The power socket equipment used in terminals and ports generally includes combined socket boxes, socket distribution boxes, interlocking socket boxes, industrial plugs and sockets, etc.1. Industrial plugs and sockets.Single-phase power supply must use three-pole plug and socket, and three-phase power supply must use five-pole or four-pole plug and socket. When the neutral line of the power supply system is grounded, four-pole plugs and sockets can be used. If not, a five-pole plug and socket must be used.Generally, the power socket used for wharf maintenance is the one with the earth pole of 6H, and plugs and sockets with other pole numbers can be used for special requirements. For example, a container freezer needs to use a plug and socket for 3H.Generally, splash-proof plugs and sockets are used in docks, and immersion-proof plugs can be used in some places where waterproof and dustproof requirements are met, such as container refrigerators.2. Interlock socket box.Because the wharf entrance is very important, we should pay attention to safety first, and often use mechanical interlocking socket boxes. This socket box can only be pulled out when the switch is 0 and the power is off, otherwise it cannot be pulled out to ensure safety.3. Combined socket box.After using safer interlocking socket, use interlocking socket with air switch to prevent overload and short circuit. This new combined socket is safer and has been widely used in docks.