This standard provides functional@ performance@ and design requirements for lubricating oil systems for diesel genarartors that provide emergency onsite power for light water reactor nuclear power plants. The standard adresses all mechanical equipment associated with the lubricating oil system@ with the exception of engine mounted components. These components@ which are mounted directly to engine structure itself@ are excluded@ except to define interface requirements. This standard also includes the lubricating oil system instrumentation and control functional requirements. It excludes motors@ motor control centers@ switchgear@ cables@ and other electrical equipment used in the operation of the lubricating oil system@ except to define interface requirements.