Opinion ID: 2968549
Heading Depth: 4
Heading Rank: 4

Heading: Class A insulation system with a

Text: temperature rise as specified in MG1-12.42 for small motors or Class B insulation system with a temperature rise as specified in MG1-12.43 for medium motors. It is designed in standard ratings with standard operating characteristics and mechanical construction for use under usual service conditions without restriction to a particular application or type of application. J.A. 14. Paragraph 1.05 of MG1-1987 thus limits general purpose motors to a maximum of 200 horsepower and requires that they be built in an open (rather than enclosed) construction.6 A subsequent version of MG1 expanded ¶ 1.05 to provide that such motors may also be built in an enclosed construction. Paragraphs 12.42 and 12.43, referenced in ¶ 1.05, make no mention of horsepower rating. 6 Open or enclosed construction, as used in ¶ 1.05, refers to the type of housing utilized in an electric induction motor. An open housing allows outside air to pass through and cool the motor during operation, while an enclosed housing does not circulate outside air. NEMA v. DOE 7 Two other aspects of the definition in ¶ 1.05 are important for our inquiry. First, it references ¶ 12.47, which sets forth, in Table 12-2, the service factor specifications for small and medium general-purpose alternating-current electric induction motors. See J.A. 72.7 Table 12-2, in turn, delineates small and medium motors at certain horsepower ratings. Specifically, for two-pole motors operating at 3600 rpm, 1 horsepower motors are small while 1.5 horsepower motors are medium. For four-pole motors operating at 1800 rpm, a .75 horsepower motor is small while a 1 horsepower motor is medium; for six-pole motors operating at 1200 rpm, a .5 horsepower motor is small while a .75 horsepower motor is medium. Second, ¶ 1.05 requires a general purpose motor to be designed in standard ratings with standard operating characteristics, which means that such motors must meet prescribed performance characteristics, one example of which is locked rotor torque as specified in ¶ 12.32. Subparagraphs 12.32.2 and .3 reflect the same delineations between small and medium motors as found in Table 12-2.8