Z4 DC Motors are for metallurgical industry, metal cutting machine ... higher than seven times.5. For frame size Z4-315, Z4-355, Z4-400 and Z4-450, compensating windings are provided. For frame ... size Z4-250 and Z4-280 the motors are feasible with a compensating winding ... include excitation lose, excluding that of separate ventilating fans. Z4 Series DC Motor