MET Group is a leader in the UK and Europe for non-invasive energised inspections and safe live operations.
Earthing Study Services
Many companies have unintentionally overlooked the importance of conducting regular earthing surveys.
Without the same level of oversight and regulation as public networks, private operators may miss these critical assessment
At MET Group, we recommend conducting an earthing study for electrical systems that fall under BS EN 50522: Earthing of power installations exceeding 1 kV A.C. This ensures your power installations are safe, compliant, and designed to manage electrical faults effectively.
Step Voltage
Touch Voltage
Earth Potential Rise
Did you Know....
"As private network operators, it is now your responsibility to maintain these systems. Conducting a comprehensive HV earthing survey will help ensure the continued safety and reliability of your electrical infrastructure."
When is an Earthing Study Required?
An earthing study is essential for electrical installations such as:
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Substations, including those for railway power supply.
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Installations on masts, poles, and towers, or switchgear and transformers located outside a controlled area.
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Power stations on a single site, including all generators, transformers, and associated electrical systems.
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Electrical systems in factories, industrial plants, and public premises.
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Installations with critical equipment like rotating machines, transformers, reactors, cables, wiring systems, and earthing systems.
Ensuring Compliance with BS EN 50522
Our earthing designs strictly follow BS EN 50522, the European standard for earthing systems in power installations over 1 kV a.c. By adhering to this standard, we minimize risks associated with electrical faults and ensure compliance with stringent CENELEC safety guidelines.
Advanced Earthing Solutions
At MET Group UK, we use industry-leading software to model earth potential rise, touch voltages, and step voltages during a fault on local or remote HV networks. This modelling provides us with the data needed to mitigate risks to both people and equipment. Our approach also takes into account nearby buildings, structures, and fences, ensuring a comprehensive safety design.
Key Components of Our Earthing Study
Touch and Step Voltages
Using advanced modelling, we ensure compliance with BS EN 50522's thresholds for touch and step voltages. Our designs incorporate fault duration and body impedance, adopting IEC 60479-1 standards for more stringent safety limits, going beyond the basic tables provided in the standard.
Transfer Potential
We address the risk of transferred potentials, where elevated voltage levels can travel through connected conductors (like metallic cable sheaths or pipelines) into low-potential areas, creating hazardous situations. Our designs ensure safe voltage levels and reduce shock hazards.
Stress Voltage
Stress voltage can occur between earthed equipment and other parts of the system during fault conditions. Our earthing systems are designed to manage these voltages effectively, ensuring that your installation remains safe and operational even under stress.
Designed for Reliability
We select materials that are corrosion-resistant and thermally robust, ensuring long-term performance and reliability in line with BS EN 50522. Our earthing systems are built to withstand fault currents without compromising structural integrity, providing you with a durable, safe solution.
Soil Resistivity Testing
Soil properties are a critical factor in earthing system performance. Using the 4-probe Wenner method, we measure soil resistivity in accordance with BS EN 50522. This allows us to design tailored earthing solutions that match the local geology and ensure optimal safety.
Ongoing Compliance and Maintenance
To ensure continued compliance, our earthing systems include provisions for periodic testing and maintenance. This helps adapt the system to any changes in the environment or operational conditions, ensuring long-term safety and performance.
This will also include Safety Checks such as Earth testing, Arc flash analysis, Safety equipment inspection. This list covers the essential maintenance tasks to ensure the safety, reliability, and compliance of high voltage systems.
Touch and Step Voltages
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Our advanced modelling validates compliance with BS EN 50522’s calculated thresholds for touch and step voltages, incorporating critical parameters such as fault duration and body impedance. MET Group UK adopt the IEC 60479-1 standard to determine permissible touch and safety voltage limits that provide more stringent permissible voltage limits in comparison to table NA.1 and NA.2 of BS EN 50522.