Ss 551 Code Of Practice For | Earthing [new]

Driven deeply into the ground vertically, or laid out as a horizontal grid (earth mat) for high-voltage substations to distribute fault currents evenly. Earthing Conductors

For electrical contractors, engineers, and facility managers, adhering to SS 551 is not just a best practice—it is a regulatory and legal necessity in many jurisdictions. Compliance ensures:

SS 551 outlines strict definitions and structural requirements for the components that comprise an earthing network: 1. Earth Electrodes

Apply anti-corrosive compounds or wrapping to buried joints and dissimilar metal connections. ss 551 code of practice for earthing

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?

Measuring earth electrode resistance using the "Fall of Potential" method or earth clamp meters before a building is commissioned.

It prevents electric shocks by ensuring that metal enclosures of electrical equipment do not stay energized during a fault. Driven deeply into the ground vertically, or laid

Horizontal copper tapes buried in trenches, ideal for sub-stations to manage step and touch voltages.

| Installation Type | Maximum Interval | |------------------|------------------| | Residential (landed / condo) | 5 years | | Commercial offices | 3 years | | Industrial plants / heavy machinery | 1 year | | Petrol stations / chemical plants | 6 months | | Lightning protection earths | 1 year (after each major storm) |

The electrode is the physical conductor (usually a copper rod) driven into the ground. SS 551 provides specific guidance on rod depth and the use of "earth enhancement compounds" in areas with high soil resistivity. The Main Earthing Terminal (MET) What is SS 551

). SS 551 mandates that a soil resistivity survey be conducted using methods like the before designing the earthing network. Soil moisture, temperature, and chemical composition directly influence resistance values. Target Resistance Values

An earthing system is buried underground and subject to chemical corrosion, mechanical damage, and soil drying. SS 551 emphasizes that an untested system is an unsafe system. Statutory Inspection Intervals

SS 551 requires all extraneous conductive parts (parts not forming part of the electrical installation but capable of introducing a potential, such as main water pipes, gas pipes, exposed structural steel, and central heating systems) to be bonded to the Main Earthing Terminal. Supplementary Bonding

Using earth testers to measure the electrode's resistance to earth.

This is non-negotiable under SS 551. All extraneous conductive parts entering the building must be bonded to the Main Earthing Terminal (MET).