5HP Air Compressor Motor: 5HP 3450 RPM. ✔ About 5HP Air Compressor Motor. 7/8″ Keyed shaft. High Efficiency :Compact structure and small size, electric motor can run at the maximum speed of 3450 rpm, high working efficiency; 5 HP electric compressor motor allows you to conserve energy over extended periods, reducing power costs and overheads.