Ss 551 Code Of Practice For Earthing -

This document is intended for electrical engineers, contractors, and safety officers working in Singapore. It outlines the critical aspects of the standard, which aligns closely with the international IEC 60364 series.

Summary Checklist for Compliance

| Item | Requirement | | :--- | :--- | | MET | Must be provided for every installation; clearly labeled. | | Earthing Conductor | Sized appropriately (min 25mm² copper usually for main; calculated for faults). | | Electrode | Resistance as low as practicable (typically <1Ω for PME/TN systems). | | Bonding | Main water/gas services bonded to MET. | | Color Coding | Protective conductors must be identified by Green/Yellow insulation or sleeving. | | Testing | Initial verification and periodic testing every 1-5 years depending on installation type. | ss 551 code of practice for earthing

One of the most important safety features in SS 551 is the requirement to bond non-electrical metallic services—such as gas pipes, water pipes, and structural steel—to the main earthing system. This ensures that in the event of a fault, all exposed metal parts remain at the same potential, eliminating the risk of a shock between two surfaces. 3. Earthing in Specialized Environments | | Earthing Conductor | Sized appropriately (min

Whether you are an electrical contractor, a licensed electrical worker (LEW), or a facility manager, understanding SS 551 is critical for regulatory compliance and operational safety. 1. What is SS 551? | | Color Coding | Protective conductors must

In Singapore, following SS 551 is not just a best practice—it is often a legal requirement under the Electricity Act. Failure to comply can lead to:

The code provides detailed guidance across several critical areas:

Lightning Protection: It provides a safe path for high-voltage surges from lightning strikes to dissipate into the ground without damaging the building’s infrastructure. 3. Core Components of an Earthing System