Insulation Class

Low Cement, Ultra-Low Cement, and No-Cement Castables are classified on the basis of calcium oxide content. These are 1—2.5, 0.2—1.0, and 0.2% CaO maximum, respectively. In the latter case the lime content is not a result of a hydrauHc setting cement constituent but comes from aggregate impurities. The insulating class is also subdivided. This division is shown in Table 14. Refractories used in steel-pouring pits are classified under ASTM C435 (Table 15). 

For lovv -voltage starters below 600 volts, the same starters are used for any voltage, since there is only one insulation class. 

Figure 1.11 Derating curve for higher ambient temperatures for insulation class E or B...

Enclosure considerations (interlocks, insulation class, shock, marking, etc.). 

Design Code AS 1210 Legal construction self supporting no internal lining no insulation Class 1 ... 

Insulation Class Type. to Mount Motor Half. ... 

Inner membrane with insulation Class Bl, flame-resistant... 

F. Motors Motors, like transformers, are another problem facing machine builders. Various standards specify construction and overload protection requirements for motors (EN 60034, 60742, 60664, 60204-1). Motors must meet the requirements for dimensions, construction, insulation class, connection, overload protection, ingress protection, markings, abnormal testing, and other parameters. 

Rated Power (KW) Rated Voltage (V) Rated Speed (rpm) Insulation Class... 

Class II Fracture suspected, but wire does not protrude through the outer insulation Class III Fracture suspected, and wire does protrude through the outer insulation Class IV Fracture suspected, and fragment of wire has migrated free from the lead... 

Today s high-visibiUty choices include waterproof, insulated Class 3 bomber jackets for the coldest weather applications. Other options include Class 3 multipurpose, breathable jackets that provide waterproof and windproof comfort. With removable liners and sleeves, these all-in-one jackets are designed for year-round use, taking the place of a vest, plus a windbreaker, winter jacket and rain jacket. 

Many older tank cars have a nominal water capacity of 11 000 gal (42 m ) and hold approximately 26 short tons (24 000 kg) of ammonia. The majority of these small tank cars are of the insulated class 105 A variety. Most of the tank cars built since the early 1960s are large uninsulated tank cars of up to 33 500-gal (127-m ) water capacity and hold about 80 short tons (73 000 kg) of ammonia. These are class 112 or 114 tank cars and are referred to as jumbo cars. Some still refer to the smaller tank cars as standard cars. Most new class DOT 105 tank cars are of the jumbo size. 

Main motors need starter overload and short circuit protection. High rupture fuses (HRC) will protect the motor against short circuit conditions, and will interrupt the electrical supply in milliseconds of the fault occurring. It is essential that fuses of this type are always fitted. Conventional overload protection, thermal or magnetic, can offer no protection to a motor with an extended acceleration time. Thermistor overload protection is the only true protection for a motor under these conditions. A thermistor is embedded in each of the motor s three windings and connected in series. The resistance of these thermistors is designed to increase rapidly at a set temperature, depending upon the insulation class of the motor. The thermistors are connected to an electronic amplifier control unit in the starter enclosure, and will trip the starter contacts when required. The device will not reset until the motor has sufficiently cooled. 

Test Prc ijre 16 bur, 31 l rotcetion CIjuk iPS4 Insulation Class H [Pg.116]

All these kinds of insulation and jacketing are presented in UL 1581. Table 11 gives the mechanical properties for PE insulation class 30.75°C. 

Insulation class standard insulation classes are B, F, and H, which establish the maximum safe operating temperature for the motor. 

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