... Norm of the Deutsche Industries-Norm. The motors are class F insulated, with reliable insulating construction and impregnating process, cnsuring ... on static thyrisier controlled supplies, or from d-c generator; f. Performances of motors all comply with State Standard GB755. ... 3000,1500,1000,750,600,500,400,300 and 200 r/min, totally nine grades. Decrease armature voltage to make speed regulating ...