Different industrial applications and environments have different requirements for the configuration of industrial plugs, sockets and couplers. In practical application, we have to choose according to the use, working environment, size, appearance, installation form, function and other aspects. Only by ensuring the correct selection of products can we ensure the safety and efficiency of the real electricity environment.
The same technology (TOWE) IPS series of industry standard plug devices, including industrial plugs, sockets, connectors, mechanical interlocks, combination socket boxes, power maintenance boxes and plastic (metal) socket boxes. The product has advanced structural design, excellent performance and quality, from simple plugs to flexible customization of the combination device by the user, complete variety, complete series, easy installation and maintenance.
Industrial sockets are divided into sockets and appliance input sockets, and their common denominator is that they can be fixed on walls and equipment for plugging in power supplies. The fixing method is the same, and they are all fixed with flanges. The difference is that the contact of the socket is a socket, while the contact of the appliance input socket is a bolt, which is defined as follows:
1) Classified according to different uses: used on the power supply line, with a cover, usually called a socket; the other type is used on the receiving equipment, called the appliance input socket;
2) Classification according to the protection level: it is divided into splash-proof type (IP44) and anti-immersion type (IP67, also known as watertight type); (3) According to the classification of grounding contact structure: divided into ground electrode and non-ground electrode, the socket with rated voltage greater than 50V and the appliance input socket have ground electrode, and the non-ground electrode less than or equal to 50V; (4) Classification according to the installation method: divided into concealed installation (also known as embedded type) and surface-mounted type (also known as wall-mounted type); (5) When the rated voltage is greater than 50V, the number of poles of single-phase and three-phase power supply is different, so the number of poles of the socket or socket is divided into 3 poles (2P+E pole (3P+E) and 5 poles (3P+N+E).
The common feature of the plug and connector is that the flexible cable must be connected, both of which are plugged in with a handlebar. The difference is that the contacts of the plug are latches, while the contacts of the connector are sockets. This kind of connection on the receiving line or electrical equipment is commonly known as a plug; The other type is connected to the power supply line, which has an outer cover, called a connector (also known as a coupler). There are also IP44 and IP67 two protection levels, this kind of connector is currently commonly used in the wire can be detached wiring, so that users can configure the cable length according to actual needs, and it is very convenient to connect with terminal blocks. 
At present, there are many different types and specifications of plugs and connector products, and their models are compiled by the manufacturers themselves. In this article, we will introduce TOWE's industrial plugs and connectors as an example, and the following figure shows the distribution of product grounding points with different voltages and frequencies in the series I (Europe) part of the standard EN60309-2:1999 + A1:2007 + A2:2012. Each color corresponds to the corresponding voltage rating. To prevent misinsertion, the pin diameter of the ground wire is larger than that of the phase wire. The user cannot arbitrarily change the location of the grounding point or any other neutral point associated with the slot or keyway. The inner core of the plug cannot be fitted into a receptacle or connector.
The TOWE IP44 socket is composed of an outer cover, a shell, a socket seat, a socket, a socket cover, a hollow rivet, a cover spring, a screw, etc. The function of the socket housing is to load and protect the internal socket and other components, and make it possible to install and fix it on the wall or in the place where it is used. The socket shell is made of PA6 material, which is fireproof and flame-retardant and anti-corrosion, and the protective cover on the socket is used to protect the socket and jack inside, which plays a dustproof, waterproof and anti-electric shock role. 
According to the provisions of GB4208-2008 "Shell IP Protection Grade", the protection performance of IP67 anti-immersion electrical accessories should meet the following requirements: IP67 industrial plug is composed of shell (integrated with bolt holder), bayonet ring, bayonet sealing ring, bolt, handlebar sealing ring, cable rack (integrated with bolt cover), cable sealing ring, metal washer, threaded gland, screw and other parts. Among them, the housing is used to protect the interior, load the latch and connect with the handlebar, and its construction is above all waterproof and sealed. The dimensions of the housing diameter, latch holder and retaining block of the anti-dip plug must meet the requirements of GB T 11919-2001. 
Similar to the splash-proof plug, there is a cable entry hole at the end of the plug, and according to the requirements of the anti-dipping structure, the structure of threaded gland plus metal gasket and rubber sealing ring is generally used. The front section of the two-section type is the shell and bolt seat, and the rear section is the handlebar. One of the two sections is designed as a groove structure that can be used to place the sealing ring. When the lock handle is pressed tightly, the anti-immersion requirements can be met. The inner hole of the bayonet ring can be put on the shell of the plug and rotate freely, and it should also prevent it from falling off. Usually the anti-shedding structure is used to ensure that the bayonet ring does not come out of the housing. The sealing ring plays the role of sealing waterproof, generally made of rubber or elastic material, according to the different sealing parts, the sealing ring of the anti-dipping plug is divided into three types:
1) It is composed of outer cover, shell, socket seat, end lining, socket cover, bayonet ring, bayonet sealing ring, flange sealing ring, plug shaft, torsion spring, screw, etc.; (2) A pair of cover lugs are provided on the socket shell for installing the outer cover and cover spring. a bayonet bevel is arranged at the front end of the plug mating port for bayonet ring locking; (3) The outer cover parts of the anti-immersion socket should be equipped with a bayonet ring and a bayonet sealing ring. The outer cover has ears, which can be turned up to plug in when in use.