NEMA enclosures

Enclosure The main cabinet is divided into two compartments one for the magnet, and one for the electronics. The magnet compartment is maintained at a temperature of 24 + 1 °C for ultimate permanent magnet stability. The electronics compartment is on a separate air conditioner and is less rigorously temperature controlled. Fignre 10.11 shows several pictures of a Qualion Process NMR spectrometer in a NEMA enclosure configured for implementation on-line. 

NEMA enclosure Hardware enclosure (usually a cabinet) that provides different levels of mechanical and environmental protection to the devices installed within it. 

A REPRESENTS NEMA ENCLOSURES TYPES EXCEEDS THE REQUIREMENTS FOR lEC 60529 IP EIRST CHARACTER SHOWN BY CYAN HATCH B REPRESENTS NEMA ENCLOSURES TYPES EXCEEDS THE REQUIREMENTS FOR lEC 60529 IP SECOND CHARACTER SHOWN BY RED BRICKS SO, NEMA 4X = IP66 FROM ABOVE CHART... 

Table XI3.6.8-1 NEMA Enclosure Rating With Interpretation ...

NEMA Enclosure Types, National Electrical Manufacturers Association Approved by NEMA Enclosures Section, November 2005. https //www.nema.org/Products/Documents/nema-enclosure-types.pdf... 

Motor enclosures. Table 3-9 lists the various NEMA enclosures for electric motors. 

Table 3-9 lists NEMA s defined types of motor enclosure and describes their main characteristics, and Table 3-10 lists the NEMA enclosures for other electrical equipment. Since sparks from electrical sources are the most common source of ignition of flammable material (Table 2-2), it is important to select the proper NEMA enclosures for motors and electrical contacts. 

FIGURE 37.19 Dedicated sample conditioning system mounted in NEMA enclosure. (Courtesy of LT Industries, Gaithersburg, MD.)... 

A motor designed for operation on a high-performance, variable-frequency drive must have considerable flexibility inherent in its construction to accomplish the variety of tasks it will be called upon to perform. A comparison of the standardized NEMA enclosures for fixed-frequency AC motors to the wide variety of DC motor constructions available demonstrates the difference in the fundamental design approach. Since hig -performance, variable-frequency drives will typically be used in DC-like applications as opposed to converting fixed-frequency AC (pumps and fans, etc.) to variable speed, it can be assumed that more DC-like construction will be required in definite-purpose AC motors. 

Environmental Enclosures Enclosures for valve accessories are sometimes required to provide protection from specific environmental conditions. The National Electrical Manufacturers Association (NEMA) provides descriptions and test methods for equipment used in specific environmental conditions in NEMA 250. Protection against rain, windblown dust, hose-directed water, and external ice formation are examples of environmental conditions that are covered by NEMA standards. 

NEMA/MG-1/1993 NEMA/MG-2/1989 Motor and generators ratings, construction, testing and performance Safety Standards (enclosures) for construction and guide for selection, installation and use of rotating machines ... 

Additional test on an IPB enclosure for radio interference as in NEMA-107. The maximum radio influence voltage (RIV) should not exceed 100 //V at 1000 kHz. For test equipment and test procedure refer to the Standard. 

The force-ventilated type is preferred when a Division 1 classification is necessary. The standard drip-proof enclosure is preferred in Division 2 or in safe locations. For an outdoor installation, serious consideration should be given to using NEMA Type 2 weather-protected enclosures rather than the completely enclosed types. 

Electrical control and enclosures AIA, ANSI, ARI, CMA, FIA, FM, IEEE, ISA, NEMA, NFPA, NSC, OIA, OSHA, UL, USCG... 

Energy Efficient (EE) Motor Designs, 628 NEMA Design Classifications, 630 Classification According to Size, 630 Hazard Classifications Fire and Explosion, 631 Electrical Classification for Safety in Plant Layout, 647 Motor Enclosures, 649 ... 

Motor enclosures for outdoor use are NEMA weather-protected Type II, totally enclosed, fan-cooled, or drip-proof with weather protection. Motors of the latter type are widely used. Not only are they less expensive than the other types, but they also have a service factor of 1,15. The above enclosure types are all suitable for the Class I, Group D, Division 2 classifications usually encountered. 

Motors shall be squirrel cage induction type with (totally enclosed, fan-cooled) (encapsulated) (splashproof) enclosure and roller-type bearings with NEMA Class A insulation. Motors shall be (single... 

Figure 10.12 shows the optical head inserted in the process line. The head is installed directly into the line, preferably via a flexible coupling for vibration isolation. The interface box is a NEMA 4.9 rated explosion proof enclosure, weighing 50 lb, which can be bolted to a wall or floor within 20 ft of the head. 

The enclosure is a NEMA type 4x, which is designed to be used either indoors or outdoors in a nonhazardous location, and which allows some protection from dirt... 

We chose a NEMA 4x enclosure and pressurized it enough so that if a leak did occur, the air inside the enclosure would move outward, and not allow hazardous gases to enter. Since the unit always had an operator in attendance to observe critical pressure changes with a dedicated pressure sensor, this was a viable alternative for short term testing of the system. The operator shuts down the system as soon as a problem is observed. 

For hazardous areas a purged and pressurized, or pressurized system and/or a NEMA 7 enclosure is appropriate. Purged and pressurized systems are evacuated and then refilled with an inert gas such as nitrogen. A pres-... 

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