The standard addresses the installation of dc power systems within controlled or limited access areas that convert commercial ac to dc voltages of 160 volts or less and those that convert from one dc level to another of 160 volts or less. This standard identifies reasonable means of minimizing hazards associated with the interconnection of dc power systems. Compliance with the standard will not assure the absence of hazards or harm resulting from the installation@ interconnection@ or operation of dc power systems. Purpose This document is a standard for use in the design@ engineering@ installation@ and acceptance of dc power systems for telecommunications environments.