THREE-PHASE GENERAL PURPOSE MOTORS; Severe Duty is standard with all WEG W22 motors. They boast a 1.25 SF resulting in cooler operation. Construction is with high grade FC200 cast iron providing superior mechanical strenght and heat dissipation. Motors are balanced to 0.08 inches per second vibration limits. Certified Class 1 Div 2, Groups A, B, C & D; Class II, Div 2, Groups F & G.