This manual provides guidance to facilities maintenance personnel in the maintenance of interior electrical systems of 600 volts and less. These systems include such components as illumination, low voltage systems, rotating equipment, motor control centers, solid-state equipment, transformers, and switchgear. It also applies to low voltage controlled devices on high-voltage systems. The procedures presented in this manual are basic and can be applied to the equipment of any manufacturer. Detailed information and instructions should be obtained from the instruction book for the particular type of equipment being serviced.