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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.
Most documents are available to anybody but a small number are confidential to ENA member companies and can only be accessed by those member companies. The system allows clients that are not full ENA members to purchase documents by credit/debit card via secure transactions provided by WorldPay.
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Tel: +44 (0)20 4599 7700Email: [email protected]
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.
Standard Application Form - Connection of Power Generating Modules to DNO Distribution Networks in accordance with EREC G99
Generation Sharing Guidance
Standard Pre-Qualification Procurement Process for Flexibility Services
Auxiliary multicore and multipair cables
Insulated Aerial Bundled Conductors For Low Voltage Overhead Distribution Systems – Conductor Fittings and Associated Apparatus
Insulator Binds and Equivalent Helical Fittings for Overhead Lines
Continuous Maximum Rated (CMR) system transformers (for use on systems up to 132 kV)
Tap-changers for system voltages up to and including 132kV
Distributed Generation Connection Guide: G98 & G99
Low voltage heat-shrinkable material components for use up to and including 600/1 000 V
DNO Common Network Asset Indices Methodology V2.1: Health & Criticality
Good Practice Guide to DNO Common Network Asset Indices Methodology V2.1
DNO CNAIM V2.0: Methodology Changes Explained
Emergency rated system transformers 66/20.5 kV, 66/11.5 kV and 33/11.5 kV delta/star and star/star connected
Partial discharge testing of bushings, capacitors, instrument transformers and switchgear of rated voltage 7.2 - 420 kV inclusive
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
Insulating foam-filled tube and solid rod for live working
Stay strands and stay fittings for overhead lines
Overhead line conductors - protection against corrosion by the application of anti-corrosion grease during manufacture
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
Design and use of temporary scaffold guards and conductor support systems
Environmental test requirements for protection and control equipment and systems
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)
Structural testing of wood poles prior to climbing or use as a personal support
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
Environmental classification and corrosion protection of structures, plant and equipment
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)
Engineering Recommendation G99/NI Issue 1 – Amendment 1 7 December 2023 Requirements for the connection of generation equipment in parallel with public distribution networks in Northern Ireland on or after 27 April 2019
Guidance on the application of Engineering Recommendation P2, Security of Supply
Security of Supply
Requirements for the Application of Protective Multiple Earthing to Low Voltage Networks
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
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
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
Enclosed unfilled terminations of cables with rated voltages 12, 24 and 36 kV
This Technical Specification (ENA TS) defines technical requirements for termination of polymeric insulated cables enclosed within unfilled earthed metal housings (cable boxes) attached to distribution switchgear and transformers. Cables, terminations and equipment within the scope of this ENA TS are of rated voltages 12 kV to 36 kV. The earthed metal enclosures are intended for housing the terminations of single and 3-core cables to BS 7870-4 (unarmoured cables), BS 6622 (armoured cables) and IEC 60502-2. Cables with conductor sizes larger than those listed in the referenced standards shall conform to the general requirements of the relevant standard. Cable terminations recognised in this ENA TS (and illustrated in Annex B) are; • separable inside or outside cone plug-in (fully screened) types for mating with appropriate standardised bushings; • fully or partially insulated (unscreened) types, e.g. heat-shrink, cold-shrink and slip-on designs. The location of inside cone type terminations does not require a separate air-filled termination enclosure (see Figure B4) and therefore Clauses 4 and 6 of this ENA TS do not apply. Terminations of other types are not excluded provided they are compatible with the enclosures as defined in this ENA TS. Detailed requirements for design and construction are not specified, but fundamental considerations on these aspects are given in Clause 5.
Distribution transformers - Part 3 Ground mounte ...
Distribution transformers - Part 2 Ground mounte ...
Emergency rated system transformers 66/20.5 kV, ...
Framework for new industrial and commercial unde ...
Switchgear for service up to 36 kV (Cable and Ov ...
Framework for new low voltage housing developmen ...
Procedure for the Conformity Assessment of Plant ...
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