What does NEMA in the crane mean for each rating?

Keyword:NEMA, crane   Time:2018-11-28 15:12:47

  There are several questions to be explained here. Some companies are different because they may install new equipment in two different  industrial facilities, indoor and outdoor. The employer then asks for an electrician's response. The system's wiring must be accommodated by a specific shell, and the specification of the wiring must be rated as NEMA. So, what does NEMA represent? What's the difference between the ratings for each NEMA? I'll explain it to you next.
 In the general market, the cranes purchased directly are marked with NEMA grades, or you have used cranes, so you must have heard the word. So what exactly determines the NEMA rating? A lot of people ask me this question directly through the mail box, so my answer is: NEMA.
 The National Electrical Manufacturers Association (NEMA) is a representative of the company, which is set up in 1926 to set standards for the production of electronic products. Any type of electrical equipment or line commonly installed in outdoor or industrial facilities is marked with NEMA shell rating.
 At the beginning, NEMA was only designed to determine the quality of electrical  equipment, components and wiring. But with the development of technology, many devices also become important and need to be protected. For example, some vulnerable electrical devices such as control devices and wiring, their applications and environment need to be protected. Companies install them in a fence or a cabinet for protection.
 Even if NEMA only determines electrical specifications and protection, they are never responsible for the electrical housing that needs to be adjusted, so they have developed a rating system to classify and adjust them. The development of the rating system has become the manufacturing standard for all kinds of fences. The electrical enclosure must match the  specific application and environment under the allocation of the rating system,  which helps to ensure that the correct operation package is used.
 The control inlet and outlet is a very important function of the NEMA rated shell. The ability of matter to enter structure or space is the entrance. The ability of material escaping structure or space is export. Another way of saying is that the entry is equivalent to another shell. Preventing substances from entering your electronic shell is the most important  rating of NEMA, but preventing substances from escaping from your electronic shell is also a job. In order to protect your electrical components and wiring, you must select the appropriate NEMA level. Below are the most commonly used NEMA ratings and their designs:
 The NEMA 1 housing is used to protect control and internal components from external objects and personnel. Generally used in indoor use, they can not be used to prevent water, dust, oil, ice and other solid  pollutants to destroy machinery, but they can protect the public to the maximum extent, and the principle is to protect workers by limiting the restrictions on potential dangerous components. Even if there is no sealing washer, use the latch door to build the NEMA case.
 NEMA 3R shell and above can protect workers, but they can only protect workers from dangerous parts. But they can also prevent the destruction  of machines by solid pollutants such as rainwater, hail, snow and external icing. They are usually used for outdoor purposes.
 There is also a NEMA 4 enclosure, which is both indoor and  practically functional, and will not be damaged by icing on the outside surface. In addition to preventing the invasion of rainwater, hail and snow,  they can also prevent entry of solid pollutants such as dust and dirt. When pressurized water is used, the NEMA 4 housing can also be directly applied to  the equipment, and the equipment is painted or cleaned with hose. The sealing  surface and the clamping door exist to seal the maximum and prevent water  inflow.
 Another shell made of stainless steel or glass fiber is the NEMA 4X housing. It is usually used in petrochemical facilities and food processing applications. Compared to the above NEMA 4 shell, they are designed for more severe environments. In the same way, solid foreign matter and contaminants invade, including dust, snow, rain and pressurized hose water, which have no effect on them. It provides additional anticorrosion levels that can be  prevented by any external ice formation damage. NEMA 4X shell is used for petrochemical facilities, so equipment must be cleaned regularly with disinfectants.
 In occasional cases, in order to protect the wiring and electrical components from the influence of water, the equipment that can be immersed in a limited depth to prevent water from entering is the NEMA 6 shell, which is mainly used indoors or outdoors.
 With the same but different functions as NEMA6, the NEMA 6P shell is designed to prevent water entry during long time immersion in limited depth. Because it provides additional anticorrosive measures and is not damaged under external icing.
 In the room, the NEMA 12 housing designed to protect the staff from their dangerous components is designed to be "knockout", which can protect the closed equipment from the invasion of solid foreign pollutants. Air dust, ground dirt, rock, fiber, cotton and fly flies are the category of foreign pollutants. They also protect the liquid into the closed equipment.
 The NEMA 4/12 shell is inspired by the feature design of NEMA 4  and NEMA 12 shell. It also protects the electrical components from the effects of solid contaminants, water and icing on the outside surface. A reversible door, hinges, and rear mounting holes are added to the original basis, which facilitates installation because the equipment may be flushed or ejected by pressure flow. In order to ensure the maximum sealing of the equipment, the surface of the gasket sealed and the clamped door is added.
 Next, the NEMA rated shells used in dangerous places are NEMA 7 shell, NEMA 10 shell, NEMA 8 shell and NEMA 9 shell. They act on devices that  contain internal explosions without causing external hazards. It is necessary to use NEMA 8 housing to prevent combustion in oil immersed equipment, and the  design of NEMA 9 shell can prevent ignition of combustible dust. The National Electrical Code (NEC) and the National Fire Protection Association (NFPA)  define these special shells.
 Next, we will introduce some related organizations and their  direction of work. In order to prevent electrical hazards, ensure the safety of  electrical design, installation and inspection work unit is the National  Electrical Code (NEC). The installation of electrical conductors, signaling  conductors, and optical cables in commercial, residential and industrial sites is NEC, and the sponsorship of NEC is NFPA, and their electrical safety standards at the workplace are called NFPA 70. What is NFPA 70? That is the  acronym for electrical and fire safety in the workplace.
 Usually used for the definition of potential explosive gas is the NEMA 7 shell, which is specially used for potentially hazardous indoor. The  same as the NEMA 7 shell is the NEMA 8 shell. They have a similar performance  between them. But the NEMA 7 shell can only be used indoors or outdoors, and  NEMA8 is designed to protect wires and electrical components immersed in oil.
 The NEMA 9 shell is the second type of equipment that has been  built as the first class of the first class 1 level dangerous places, and its definition is determined by the North American classification system and the National Fire Protection Association (NFPA). 7.8.9 the potential dust hazard of  the three kinds of housings in normal operation.
 The requirements of the mine safety and health administration  can be satisfied by the NEMA 10 shell design.
 With the increasing use of electrical products, the demand for  electrical safety production regulations is growing. It has far exceeded other power devices. In order to ensure the compatibility of the equipment, ensure the safety of the workers, and continue to develop new standards for the developing electric industry, NEMA has established a simple classification process.

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