The neutral source is earthed at the transformer, but the consumer's local electrical installation relies on an independent earth electrode driven locally into the ground. 2. Equipment Earthing (Protective Earthing)
Modern engineering demands specialized earthing applications. SS 551 provides tailored guidance for high-stakes environments: Data Centers and IT Infrastructure
In high-risk areas like bathrooms, laboratory spaces, or damp industrial floors, local supplementary bonding must connect all localized metal fixtures together to guarantee zero voltage variance. Earth Electrode Installation Standards ss 551 code of practice for earthing
A critical focus of SS 551 is eliminating potential differences within a building. During a major electrical fault or a lightning surge, different metal structures can momentarily sit at vastly different voltages. If a person touches two different metal surfaces simultaneously, they can bridge this gap and suffer a fatal shock.
One of the most emphasized sections of SS 551 is bonding. This involves connecting all exposed conductive parts (metal pipes, structural steel) to the earthing system to ensure there is no voltage difference between them, which could cause a shock if touched simultaneously. 4. Key Design Considerations The neutral source is earthed at the transformer,
SS 551 is the Singapore Standard that provides comprehensive guidance on meeting the requirements for the earthing of electrical installations. It is a modified adoption of BS 7430:2011+A1:2015, “Code of practice for protective earthing of electrical installations,” published with the permission of British Standards Limited.
The Definitive Guide to SS 551: Code of Practice for Earthing If a person touches two different metal surfaces
The practice of connecting all exposed and extraneous conductive parts (such as metal water pipes, structural steel, and gas lines) to the main earthing system to ensure they remain at the same electrical potential. System Earthing vs. Equipment Earthing
Singapore’s provides the critical framework for designing, installing, and maintaining earthing systems in low-voltage electrical installations.
[ Electrical Equipment ] │ ▼ (Circuit Protective Conductor - CPC) [ Main Earthing Terminal ] │ ▼ (Earthing Conductor) [ Earth Electrode / Rod ] │ ▼ ======= EARTH =======
This is non-negotiable under SS 551. All extraneous conductive parts entering the building must be bonded to the Main Earthing Terminal (MET).