BS EN 50522-2022 + A1-2024 PDF

Full title and description

STB BS EN 50522-2022 + A1-2024 — Earthing of power installations exceeding 1 kV a.c. (British adoption of EN 50522:2022 with Amendment A1:2024). This standard gives requirements and guidance for the design, installation, measurement, testing, maintenance and inspection of earthing systems for electrical power installations with nominal AC voltage above 1 kV (up to and including 60 Hz), including substations, outdoor switchgear, transformer installations and other HV facilities.

Abstract

This document specifies principles and technical measures to achieve safe and functional earthing (grounding) of high‑voltage power installations. It covers fundamental safety criteria (touch and step voltages), design methods and calculation procedures, selection and installation of earth electrodes and conductors, measurement and verification methods, maintainability and inspection, plus coordination with lightning protection and other earthing systems. It also notes where IEC 61936‑1 text is referenced and where national implementation details apply.

General information

• Status: Current (BS national adoption of EN 50522:2022 with Amendment A1:2024 implemented as BS EN 50522:2022+A1:2024).
• Publication date: EN 50522:2022 (CENELEC publication 2022); British adoption (BS EN 50522:2022) published in the UK during 2022–2023; Amendment A1 issued/implemented in late 2024 (BS EN 50522:2022+A1:2024 — amendment published/marketed November 2024, implementation/notification recorded end‑November 2024).
• Publisher: British Standards Institution (national publication: BS EN 50522:2022 + A1:2024); origin: CENELEC / EN (EN 50522:2022).
• ICS / categories: 29.120.50 (Fuses and other overcurrent protection devices) — electrical engineering / power installations.
• Edition / version: BS EN 50522:2022 + Amendment A1:2024 (commonly shown as BS EN 50522:2022+A1:2024).
• Number of pages: National and vendor listings show the consolidated BS EN 50522:2022+A1:2024 publication at approximately 114 pages (EN-only editions commonly listed ~77–80 pages; combined national/amended PDF/page counts vary by publisher).

Scope

Applies to the specification, design and erection of earthing systems for electrical power installations with nominal voltages above 1 kV a.c. and nominal frequency up to and including 60 Hz, to provide safety and correct functioning in intended use. Examples: substations (including railway supply substations), electrical installations on masts/poles/towers, outdoor switchgear and transformers, generating stations, industrial power systems and offshore power installations. The standard excludes certain items (e.g., scope exclusions noted in the text such as mining equipment, some ship/installation specific rules and live working procedures) and cross‑references IEC and other standards where appropriate.

Key topics and requirements

• Fundamental safety criteria for earthing: permissible touch and step voltages and safety limits under fault and transient conditions.
• Design methods and calculation procedures for earthing systems, including soil resistivity testing, modelling of earth electrode systems and required conductor sizing.
• Selection, installation and arrangement of electrodes, earth meshes, ring conductors, rods and buried conductors; installation details to achieve required performance and durability (including corrosion protection).
• Requirements for equipotential bonding, system partitioning and the interface between HV earthing, building equipotential systems and lightning protection.
• Measurement, testing and verification procedures (on‑site resistivity and earth fault verification) and acceptance criteria.
• Maintainability: inspection intervals, record keeping and re‑testing after significant changes or events.
• Coordination with related standards (textual references to IEC 61936‑1, and normative/informative references to other EN/IEC documents for lightning, short‑circuit/current calculations and testing).

Typical use and users

Used by electrical engineers and designers (substation and power systems), utility network designers and operators, consulting engineers, installation and commissioning contractors, testing and inspection organisations, asset owners and regulators responsible for HV earthing arrangements and safety. Also used by specialists preparing specifications, procurement documentation and safety assessments for substations, overhead/underground line terminations and HV equipment sites.

Related standards

Key related and frequently cross‑referenced standards include: IEC 61936‑1 (Power installations exceeding 1 kV a.c. — common rules), standards for lightning protection (e.g. IEC/EN 62305 family), EN/IEC short‑circuit and calculation standards (EN 60909 series), EN/IEC documents for lightning protection components (e.g. EN IEC 62561), and national wiring/earthing rules where applicable. EN 50522:2010 is the superseded edition. The standard explicitly references IEC 61936‑1 and other normative documents for calculation and testing methods.

Keywords

earthing; grounding; high voltage; substations; touch voltage; step voltage; earth electrode; soil resistivity; equipotential bonding; lightning protection; IEC 61936‑1; earthing measurement; maintenance; BS EN 50522; BS EN 50522:2022+A1:2024.

FAQ

Q: What is this standard?

A: It is the European/British standard for the earthing (grounding) of electrical power installations with nominal AC voltage above 1 kV, published as EN 50522:2022 and adopted in the UK as BS EN 50522:2022 with Amendment A1:2024 (BS EN 50522:2022+A1:2024).

Q: What does it cover?

A: Design and erection of earthing systems for HV installations (substations, outdoor transformers, feeders, generating stations), safety limits (touch/step voltages), earthing conductor and electrode arrangements, measurement and testing procedures, maintainability and coordination with lightning protection and other standards.

Q: Who typically uses it?

A: Power system designers, substation engineers, utilities, contractors, inspectors and consultants responsible for HV earthing design, testing and asset management.

Q: Is it current or superseded?

A: The 2022 edition (EN 50522:2022) replaced the 2010 edition; the consolidated national British text with Amendment A1 (2024) is current at publication and implementation (BS EN 50522:2022+A1:2024). Check national adoption records for local implementation dates.

Q: Is it part of a series?

A: It sits within the CENELEC/IEC family of power‑installation standards and is aligned with IEC 61936‑1 (power installations >1 kV) and other EN/IEC documents addressing lightning protection, short circuit calculations and earthing testing procedures. It complements national wiring regulations and other EN/IEC publications rather than forming a numeric series of consecutive parts.

Q: What are the key keywords?

A: Earthing, grounding, high‑voltage, touch voltage, step voltage, earth electrode, soil resistivity, equipotential bonding, lightning protection, testing and measurement.