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The Energy Networks Association (ENA) represents the interests of all energy companies in the UK. The Document Catalogue System is an online catalogue of engineering documents available from the ENA.
Documents available from the site include Technical Specifications, Engineering Recommendations and Reports, BEBS Specifications and reports supporting the electricity network process and policies.
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WARNING! Some of the older (pre 2003) documents available on this site were originally published by the now defunct Electricity Association. Please note that the ENA cannot take responsibility for the condition and content of these older documents and you are advised to seek advice before acting upon information held in them.
Distributed Generation Connection Guide: G98 & G99
Low voltage heat-shrinkable material components for use up to and including 600/1 000 V
Emergency rated system transformers 66/20.5 kV, 66/11.5 kV and 33/11.5 kV delta/star and star/star connected
Low voltage overhead line shrouding materials
Aerial Bundled Conductors Insulated with Cross-Linked Polyethylene for Low Voltage Overhead Distribution
Fault Passage Indicators up to 132kV for Underground and Overhead Distribution Systems
Operational procedure associated with electricity supplies for traction purposes on AC and DC electrified lines
Code of practice for the coordination of power line carrier system frequencies in the range 30•0 kHz to 526•5 kHz
Issue 3 - Amendment 8
Recommendations for the Connection of Generating Plant to the Distribution Systems of Licensed Distribution Network Operators
Recommendations for the safe working of utilities’ staff and other parties near light rapid transit systems
Issue 1 – Amendment 10
Requirements for the connection of generation equipment in parallel with public distribution networks on or after 27 April 2019
Technical Requirements for Customers’ Export and Import Limitation Schemes
Specification for single circuit overhead pole lines for use at high voltage up to and including 33 kV
Guidance on the application of Engineering Recommendation P2, Security of Supply
Security of Supply
Environmental classification and corrosion protection of structures, plant and equipment
Structural testing of wood poles prior to climbing or use as a personal support
Tests on power cables with XLPE insulation and metallic sheath and their accessories, for rated voltages of 66 kV (Um = 72.5 kV), 110 kV (Um 123 kV) and 132 kV (Um = 145 kV)
Guidance on Neutral Current Diversion
400 V a.c. switchgear, controlgear and fusegear assemblies
Public Electricity Network Distribution Assemblies
Outdoor, free standing CTs & VTs up to 36 kV
Design and use of temporary scaffold guards and conductor support systems
Insulated Aerial Bundled Conductors for Low Voltage Overhead Distribution Systems – Erection Requirements
Covered-conductors for overhead lines (having rated Voltages Uo/U greater than 0.6/1 kV up to and including 19/ 33 kV)
Stay strands and stay fittings for overhead lines
Earth rods and their connectors
Environmental test requirements for protection and control equipment and systems
Application of ancillary electrical equipment
Standard numbering for small wiring (for switchgear and transformers together with their associated relay panels)
Engineering Recommendation G100 Issue 2 Overview and Summary Guide
Requirements for the Application of Protective Multiple Earthing to Low Voltage Networks
National Equipment Defect Reporting Scheme (NEDeRS®) – Notes of guidance
Overhead line conductors - protection against corrosion by the application of anti-corrosion grease during manufacture
Insulating foam-filled tube and solid rod for live working
Guidance for the operation and management of fluid filled cables. This document replaces ETR 135.
Distribution cables of rated voltage 0.6/1/ (1.2) kV with XLPE insulation, concentric waveform copper wire and solid aluminium conductors
Guidelines for the Provision of Low Voltage Connections to Multiple Occupancy Buildings
Switchgear for use on 66 kV to 132 kV distribution systems Part 5 Inductive voltage transformers, capacitor voltage transformers, combined unit transformers and current transformers for use on 72.5 kV to 145 kV distribution systems
Switchgear for use on 66 kV to 132 kV distribution systems (Disconnectors and earthing switches)
Measures necessary to minimise corrosion damage to buried metallic structures by neighbouring cathodic protection installations
Power installations exceeding 1 kV a.c. – Design of high-voltage open-terminal stations
Aerial bundled conductors insulated with cross-linked polyethylene for low voltage overhead distribution
Specification for single circuit overhead lines of compact covered construction on wood poles for use at high voltage up to and including 33 kV
XLPE covered-conductors for overhead lines (having rated voltages Uo/U greater than 0.6/1 kV up to and including 19/33 kV)
Partial discharge testing of bushings, capacitors, instrument transformers and switchgear of rated voltage 7.2 - 420 kV inclusive
Single core cables for use in substations having extruded insulation and rated voltages of 6350/11 000 volts, and 19 000/33 000 volts
Type approval tests for mechanical connections to metallic sheaths of cables Addendu
Distribution transformers - Part 4 Pole mounted transformers
Fittings for covered conductors for overhead lines (having rated voltages U0/U greater than 0.6/1 kV up to and including 19/33 kV)
Portable earthing equipment for overhead lines and substations
Switchgear for service up to 36 kV (Cable and Overhead conductor connected)
Complexity of Distribution Circuits Operated at or above 22kV
Specification for single circuit overhead lines on wood poles for use at 132kV
Guide to the application of Engineering Recommendation G5/4 in the assessment of harmonic voltage distortion and connection of non-linear equipment to the electricity supply system in the U.K
Calculation of fault currents in three-phase AC power systems (Application Guide to Engineering Recommendation G74)
Analysis package for assessing the security contribution from distributed generation and electricity storage systems – Users’ guide
Analysis Package For Assessing Generation Security Capability - Users' Guide
Harmonic voltage distortion and the connection of harmonic sources and/or resonant plant to transmission systems and distribution networks in the United Kingdom
Amendment 7
Issue 2 Amendment 3 Recommendations for the Connection of Type Tested Small-scale Embedded Generators (Up to 16A per Phase) in Parallel with Low-Voltage Distribution Systems
Issue 1 Amendment 4 Requirements for the connection of generation equipment in parallel with public distribution networks on or after 27 April 2019
Voltage fluctuations and the connection of disturbing equipment to transmission systems and distribution networks in the United Kingdom
EREC G99/NI - Northern Ireland Only
Requirements for the connection of generation equipment in parallel with public distribution networks in Northern Ireland on or after 27 April 2019
Guidelines for the design, installation, testing and maintenance of main earthing systems in substations
A guide for assessing the rise of earth potential at electrical installations
Framework for new low voltage housing development installations - Part 1 Design and planning
Framework for new low voltage housing development installations - Part 2 Materials specification
Framework for new low voltage housing development installations - Part 3 Installation and records
Framework for new industrial and commercial underground connections - Part 4 Design and planning
Framework for new industrial and commercial underground connections - Part 5 Materials specification
Framework for new industrial and commercial underground connections - Part 6 Installation and records
Framework for contestable diversionary and reinforcement works not exceeding 33 kV - Part 7 Contestable diversionary and reinforcement works
Requirements for the connection of Fully Type Tested Micro-generators (up to and including 16 A per phase) in parallel with public Low Voltage Distribution Networks on or after 27 April 2019
This EREC G98 provides guidance on the GB technical requirements for the connection of Micro-generators in parallel with public Low Voltage Distribution Networks. The requirements set out in this EREC G98 are in addition to those of European standard EN 50438 which should be complied with in full. There are two connection procedures described in this document.
The first connection procedure covers the connection of a single Micro-generating Plant. A Micro-generating Plant is a single electrical installation that contains one or more Micro-generators, either single or multi-phase, the aggregate Registered Capacity of which is no greater than 16 A per phase2. The second connection procedure covers the connection of multiple Micro-generators (other than within a single Customer’s Installation) in a Close Geographic Region, under a planned programme of work.
This document is applicable to Fully Type Tested Micro-generators for which a Micro-generator Type Test Verification Report demonstrates that the Micro-generator design meets all the requirements set out in this EREC G98. For Micro-generators greater than 16 A per phase the procedures described in EREC G99 apply.
Full guide of connection documentation
Minor technical modifications: 1. Removal of sentence in Foreword that is out of date. 2. Removal of reference to EN 50438, which has been withdrawn, and re-instatement of relevant clauses. Includes modifications to Foreword; 1.4; 2.1; 2.8 (clause removed); 2.12; 3.2; 6.2.2; 7.2.1 (including new Figure 1); 7.3.1; 7.7; 9.3; 9.5; 9.6; 10.1.10; 10.2; 11.1; 11.2; 11.3; 11.4; Form C Type Test Verification Report; Annex A1 (A1.1, A.1.2.2, A.1.2.3, A.1.2.7, A.1.2.9, A.1.2.10, A.1.3.2, A.1.3.4, removal of A.1.3.7); and Annex A2 (A.2.2.4, A.2.3.2, A.2.3.4, removal of A.2.3.5). 3. Clarification in 2.8 that the threshold is less than or equal to 16 A per phase. 4. Amended product ID to system reference in 2.13 and in forms, as per updates to ENA Type Test register. 5. Updates to the titles of EREC G5 and EREC P28 in the references. 6. New references to cyber security guidance documents, a requirement to comply with these in a new clause 9.7 and additional check on compliance in Form C: Type Test Verification Report. 7. Modification to the definition of Registered Capacity to align with the latest version of EREC G99 and to include footnote. 8. Allowing for a family approach to type testing in new clauses from 6.3. 9. Removal of FIT meter in Figure 2 Example of circuit diagram and combined import / export meter in Meter Operator’s installation. 10.New clause 8.4.4 on substantial modifications to EREC G83 installations, including new footnote. 11.New clauses 9.3.3 and 9.3.4 on minimum stable operating level during LFSM-O. 12.Addition of field for energy storage capacity (kWh) for energy storage devices in Form A and Form B. 13.Updates to the energy source / energy conversion technologies table at the end of Form B Installation document, Appendix 3. 14.Modifications to recognise the limitations of small rotating machines to operate stably at low output, including changes to Form C: Type Test Verification Report (new footnotes 7 and 8) and additional guidance in A.2.2.4 and A.2.3.1. 15.Modifications for Form C: Type Test Verification Report including: PUBLISHING AND COPYRIGHT INFORMATION a. Additional guidance; b. New operating range tests (Test 1 47.0 Hz, Test 5 continuous operation and Test 6 RoCoF withstand); c. A field in the harmonics test sheet to indicate, for 3-phase Microgenerators, whether measurements for all phases are the same; d. Moved fields for test dates and location to top of voltage fluctuations and flicker test sheet; e. Removed four rows in the Power Factor test sheet for results at different levels of Registered Capacity and replaced with a single row for measured output (aligned with equivalent G99 forms); and f. Added a clear check box for logic interface port and new requirement to provide a high-level description of the logic interface. 16. A small number of minor typographical corrections throughout
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