Understanding the history of SS 551 provides valuable context for its current provisions. The standard's lineage traces back to , which was first published in 1981. This Code of Practice (CP) was subsequently revised in 1991. In a significant move to align with modern standards management, CP 16 was renumbered and updated to become SS 551:2009 .
SS 551 aligns with international standards (such as IEC 60364) in defining types of system earthing. In Singapore's electrical infrastructure, the most common configurations are: TN-S System ss 551 code of practice for earthing