The purpose of this subpart is to define types of emergency lighting and power systems.

A manual emergency lighting and power system is one in which a single manual operation, such as the manual operation of a switch from an “off” to an “on” position, is necessary to cause the emergency power source to supply power to the emergency loads.

An automatic emergency lighting and power system is one in which a reduction in potential from the ship's service power and lighting plant causes the emergency power source to supply power to the emergency loads.

A temporary emergency power source is one of limited capacity that carries, for a short time, selected emergency loads while an emergency power source of larger capacity is being started.

A final emergency power source is one that automatically supplies power to the emergency loads under § 112.15-5 and automatically transfers the temporary emergency loads under § 112.15-1 when the potential of the final emergency source reaches 85 to 95% of normal value.