Annex 1 and Annex 2 Documents

Standards and other documents referenced in Annex 1 and Annex 2 of the Distribution Code are available for free and can be downloaded below:

Annex 1 Documents

1. Engineering Recommendation G5/4-1

Planning levels for harmonic voltage distortion and the connection of non-linear equipment to transmission and distribution systems in the United Kingdom

2. Engineering Recommendation G12/4-1

Requirements for the application of protective multiple earthing to low voltage networks

3. Engineering Recommendation G59/3 Amendment 3

Recommendation for the connection of generating plant to the distribution systems of licensed distribution network operators

3. Engineering Recommendation G59/3 Amendment 4. (effective from 1 July 2018)

Recommendation for the connection of generating plant to the distribution systems of licensed distribution network operators

For further forms and information pertaining to Engineering Recommendation 59/3-4 please click here to guide you through the processes that follow.

4(a). Engineering Recommendation P2/6

Security of Supply

4(b). P0-PS-037 (EM7907)

Distribution planning standards of voltage and of security of supply. (Parts of Scottish Hydro Electric Power Distribution Ltd Area)

5. Engineering Recommendation P24

AC traction supplies to British Rail

6. Engineering Recommendation P25, Issue 2 - 2018

The short-circuit characteristics of single-phase and three-phase low voltage distribution networks.

7. Engineering Recommendation P28

Planning limits for voltage fluctuations caused by industrial, commercial and domestic equipment in the United Kingdom

8. Engineering Recommendation P29

Planning limits for voltage unbalance in the United Kingdom for 132kV and below

9. Technical Specification 41-24 November 2018

Guidance for the design, installation, testing and maintenance of main earthing systems in substations

10. Engineering Recommendation S34

A guide for assessing the rise of earth potential at substation sites

11. Engineering Recommendation G83/2

Recommendations For The Connection of Type Tested Small-Scale Embedded Generators (Up To 16 A Per Phase) In Parallel With Public Low-Voltage Distribution Networks

11. Engineering Recommendation G83/2 Amendment 1 (effective from 1 July 2018)

Recommendations For The Connection of Type Tested Small-Scale Embedded Generators (Up To 16 A Per Phase) In Parallel With Public Low-Voltage Distribution Networks

For further forms and information pertaining to Engineering Recommendation G83/2-1 please click here to guide you through the processes that follow.

12 Engineering Recommendation G98/1-1(2018)

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

For further forms and information pertaining to Engineering Recommendation G98 please click here to guide you through the processes that follow.

13 Engineering Recommendation G99/1-1(2018)

Requirements for the connection of generation equipment in parallel with public distribution networks on or after 27 April 2019

For further forms and information pertaining to Engineering Recommendation G99 please click here to guide you through the processes that follow.

Annex 2 Documents