scope:

This guide will consider the components of both the ac and dc systems and provide guidelines and recommendations for designing the appropriate systems for the substation under consideration. This guide covers the low voltage auxiliary systems from the source(s) to the distribution point(s). Reliability requirements and load characteristics are discussed and distribution methods are recommended.

Purpose

The low voltage ac and dc auxiliary systems comprise very important parts of the substation equipment. The design of the ac and dc auxiliary systems facilitates the safe and reliable operation of the substation. This guide considers various factors that affect the design of the ac and dc auxiliary systems such as reliability, load requirements, system configurations, personnel safety and protection of auxiliary systems equipment.