400A 3 Phase Electrical Manual Changeover Change Over Transfer ... A 400A manual changeover switch is a 3 or 4-pole, high-capacity, on-load, hand-operated device used to safely switch a 400-ampere electrical load between two sources (e.g., mains and generator). It ensures isolation, often with 3 positions (I-0-II), typically rated for 400A AC23A (690V) or DC applications.