標準號：IS 2972 Pt.3-1979
發布日期：1980/8/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This standard ( Part III ) covers squirrel-cage three-phase induction motors for driving textile spinning frames on system voltage not exceeding 650 V and having rated outputs from 3.7 to 22 kW.1.2 This standard covers the output frame assignments for 4-pole and 6-pole single-speed motors and 4/6 and 6/8 pole two-speed motors with class E and B or F insulations for spinning frame motors. However, motors of smaller outputs in smaller frame numbers having speed-torque characteristics outlined in 12 may be used for other spinning frames. In case of two-speed motors there is a scope for obtaining higher outputs than those assigned in Table 3. This shall be a matter of agreement between the manufacturer and the purchaser.1.3 The motors covered by this specification have either Class 'A', 'E' and 'B', or 'F' insulation with their associated temperature-rises as outlined, in 12 of IS : 325-1978〓.