Low frequencies are convenient for large, slow motors like hoists and trains and will have lower inductive losses. For small, fast motors, a higher frequency ma

Low frequencies are convenient for large, slow motors like hoists and trains and will have lower inductive losses. For small, fast motors, a higher frequency may be more convenient. Lights, both incandescent and florescent, will flicker if the frequency is low. Aircraft and spacecraft use 400Hz because the equipment can be lighter and smaller.