Enclosure types

This is a location which is not permanently contaminated but is likely to be prone to fire hazards during processing, storage or handling of explosive gases, chemical vapour or volatile liquids, although under careful and controlled conditions. Eor such locations in addition to a flame- or explosion-proof enclosure, type Ex. d, an increased... 

Relative Cost of Three Enclosure Types 2,300-volt, 1,200-rpm Motors... 

The first step in selecting motors for large compressors (1,500 hp and over) is to determine the motor voltage, speed, and enclosure type. 

The selection of the motor enclosure type involves not only economics but also assessment of two factors area hazard classification and other area operation conditions. 

Operating conditions that also must be considered in selecting the enclosure type are exposure to airborne dust, dirt and moisture, the possibility of corrosive dust or vapors in the area, and the expected maximum ambient temperature. 

Motor enclosure types for compressor service under shelters are applied as follows ... 

The drip-proof enclosure offers a ventilating sy.stem that is not dependent on external auxiliaries. Its installed cost is the lowest of all the enclosure types. Standard drip-proof ratings above 500 rpm may have a 1 15... 

Rim exhausts are suitable for area sources of contaminant. They are limited in the area over which they can draw with adequate velocity. In practice, the slot hood should be within 0.6 m of the far edge of the source. For an open surface tank this means that a slot hood on one long side is necessary for tanks up to 0.6 m in width hoods on both long sides are necessary for tanks up to 1.2 m in width and rim exhaust is not practical for tanks wider than 1.2 m. For those situations, push-pull ventilation or enclosure type hoods are recommended.- ... 

After an area classification has been established, then anelectrical equipment, instruments, and wiring must adhere to that classification. Therefore, some motor enclosure types would not be electrically acceptable for specific area classifications. 

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. 

This parabola defines the area of flame transmission through the joint. Its vertex is usually nearby or somewhat below the stoichiometric point. All gases show a behaviour similar to that shown in Fig. 1.3. The knowledge of the vertex MESG values of gas-air or vapour-air mixtures is essential for the construction and use of enclosures, type of protection flameproof... 

Figure 6.88 Longitudinal section drawing of a flameproof cage induction motor, bearings outside the flameproof enclosure. Type of protection EEx de IIC T4.

A well-known construction of a flameproof luminaire uses a glass tube as luminaire body, fitted with two end covers forming a flameproof enclosure, type of protection (E)Ex dll C T5 or T6 respectively. 

Despite their common usage, direct radiators achieve their modern success through the accumulated improvement of many decades of experience with such diverse problems as voice coil heat buildup, diaphragm nodes, enclosure types, and the compHcations of multiple radiator/crossover networks. 

The cabinet itself will vibrate and reradiate into the sound field to some extent for most enclosure types. In general, the more dense the enclosure material, the less susceptible the unit will be to reradiation. Nonetheless, some modern loudspeakers employ aluminum, synthetic resins, and even foamed plastic for enclosure construction. Various techniques such as bracing, damping, and layered enclosure construction can be employed with good success in suppressing cabinet radiation. 

Enclosure types Mainly two standards, namely, lEC 60529 and National Electrical Manufacturer Association (NEMA), are used in industries for enclosures pertinent to electrical systems. Both these standards are covered briefly during the discussions. Discussions will be concluded by providing a comparison between them (Fig. X/3.6.8-2) ... 

DEVELOPED BASED ON NEMA 250 2003 NEVA ENCLOSURE TYPES COURTESY NEMA 250 2003... 

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... 

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

It is better to try to find the type of enclosure best suited for different applications [2]. From Table APII/2.1-1, various enclosure types and intrinsic safety can be selected based on application. This is a limited guide table with electrical apparatuses only. 

The enclosure type of hearing protection completely surrounds the head like an astronaut s helmet. This t e of protection is not too popular due to its cost and discomfort. 

SOLID-STATE VARIABLE-SPEED AC MOTOR CONTROLS CONTROL OF DC MOTORS DC Motor Starting and Braking Speed Control DC Drive Characteristics PROTECTION OF MOTOR CONTROLLERS Electrical Enclosure Types and Specifications Motor Overload (Running) Protection Other Types of Motor Protection Short-Circuit Protection Protection of Solid-State Motor Controls COMBINATION STARTERS Interrupting Rating... 

Environment. This will determine the enclosure type.The open-chassis type is also available for installation in other enclosures. 

If leveling motors are included in the sensor, a remote leveling process is initiated via an external electrical signal or at a configurable time after power-on otherwise manual leveling by adjustment of set screws is sometimes needed. All enclosure types except vault enclosures require remote leveling capability. 

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