EDS GUIDANCE FOR THE APPLICATION OF ENA ENGINEERING RECOMMENDATIONS G88 AND G81 - INSET NETWORKS (IDNOS AND OTHER LICENSED DNOS)

Transcription

1 THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE ENGINEERING DESIGN STANDARD EDS GUIDANCE FOR THE APPLICATION OF ENA ENGINEERING RECOMMENDATIONS G88 AND G81 - INSET NETWORKS (IDNOS AND OTHER LICENSED DNOS) Network(s): EPN, LPN, SPN Summary: This document has been published to provide information and guidance on the application of ENA G88.The document G88 published by the Electricity Networks Association as a guidance document for the Planning, Connection and Operation of Electricity Networks Owner: Allan Boardman Approved By: Steve Mockford Approved Date: 16/06/2015 This document forms part of the Company s Integrated Business System and its requirements are mandatory throughout UK Power Networks. Departure from these requirements may only be taken with the written approval of the Director of Asset Management. If you have any queries about this document please contact the author or owner of the current issue. Applicable To UK Power Networks All UK Power Networks Asset Management Capital Programme Connections External G81 Website Contractors ICPs/IDNOs Meter Operators HSS&TT Network Operations UK Power Networks Services Other

2 Revision Record Version 6.0 Review Date 01/01/2017 Date 16/06/2015 Author S. Cuddihey Why has the document been updated: Periodic document review. Review date further extended to tie in with the revision of national standard ENA ER G88. What has changed: Emergency trip button now refers to EDS Section 5.1 revised. Formatting has been updated in line with the template. Version 5.0 Review Date 31/05/2013 Date 17/01/2013 Author Allan Boardman / S.Cuddihey Temporary amendment for provision of emergency trip awaiting outcome of ENA review & Removal of reference to EDS Version 4.1 Review Date 17/01/2013 Date 12/07/2012 Author Allan Boardman Reviewed for publishing on G81 website Version 4.0 Review Date 12/07/2012 Date 08/12/2011 Author Pete Lawson Metering requirements amended Version 3.0 Review Date 08/12/2011 Date 11/11/2010 Author Pete Lawson Modified to include reference CCCM 1/11/2010 Version 2.0 Review Date 11/11/2010 Date 09/09/2010 Author B.Hoare / P.Lawson Include revisions to G88 (2009) Version 1.0 Review Date 09/09/2010 Date 16/05/2006 Author Bob Bassett First Issue UK Power Networks 2015 All rights reserved 2 of 30

3 Contents 1 Scope Introduction Definitions Planning Guidelines IDNO to Specify Site Location and Demand Point of Connection Standard Planning Details Network Ownership Boundary General Electrical Arrangements Boundary Access Arrangements Boundary Equipment Boundary Metering Connections Low Voltage Cable Network Connection Standard LV Service Arrangement: Standard LV Supply Interface at Fuse Cabinets, Feeder Pillars and Link Boxes HV Supply from Networks owned by UK Power Networks HV Circuit Connection HV Substation Connection EHV/Primary Substation Connection Building Design, Civil Works and Legal Aspects Building Design Access and Egress Arrangements Civil Works Substations Legal Minimum Cost Scheme, Apportionment and Network Optimisation References Appendix A Supportive Information and Historical Reference Documents UK Power Networks 2015 All rights reserved 3 of 30

4 1 Scope This Engineering Design Standard specifies the supply arrangements provided to Inset Networks owned by Licensed Distribution Network Operators and should be read in conjunction with the published UK Power Networks Connection Charging Statement and Methodology. Due to the on-going evolution of OFGEM decisions and determinations, this Standard shall be reviewed frequently. 2 Introduction ENA Engineering Recommendation ER G88 (dated 2006) Principles for the Planning, Connection and Operation of Electricity Distribution Networks at the interface between Distribution Network Operators (DNOs) and Independent Distribution Network Operators (IDNOs), was last updated in October This Engineering Design Standard takes into account the October 2009 revision and March 2010 OFGEM decision which is summarised below: The cost of the boundary metering, if required, is to be borne by the DNO. Portfolio billing will be introduced from 1 April In October 2011 UK Power Network s standard with regard to boundary metering of HV IDNO projects changed and the requirement for HV metered boundaries, including close coupled DNO/IDNO substations ceased. The requirement for new EHV metered boundaries ceased in April 2012 but currently existing EHV boundary metering will remain supported for research purposes. ENA Engineering Recommendation ER G81 (Amendment 1 dated Jan 2008) Part 1: Design and Planning, specifies the general design process and design approval procedure and is a support document to ENA ER G88. The UK Power Networks Connection Charging Statement provides the basis of charges for the provision of a connection whilst the connection Charging Methodology describes the methodology under which customers will be charged for a connection. UK Power Networks has no responsibility for or jurisdiction over, the specification and design of the IDNO s network. UK Power Networks 2015 All rights reserved 4 of 30

5 3 Definitions Independent Connections Provider(ICP) CB CDCM Contestable Work DIN DNO EDNO EHV ENA HV IDNO Inset Networks /Embedded Network LDNO LTDS LV Majority Asset Owner NAMP Non Contestable Work OFGEM POC POS/network Ownership Boundary An ICP can undertake contestable works. An ICP is a company that has been approved and included on the Lloyd's Register list of Contractors under the National Electricity Registration Scheme (NERS). These companies build electricity networks to the specification and quality necessary for them to be adopted (owned) by UK Power Networks. Circuit-breaker Common Distribution Charging Methodology Work that can be undertaken by someone other than UK Power Networks, this includes the provision of materials to form the connection, trenching, other site preparation work and the construction of the connection. Dangerous Incident Notice Distribution Network Operator Public Electricity Supply Licence holders for the original 14 UK electricity supply networks Abbreviation for the private network operator as a license exempt distribution network operator, to differentiate these license exempt distributors from IDNO s who hold a distribution license. The arrangements for EDNO s are NOT included in this Standard. Extra High Voltage High Voltages above 11kV used for Primary Distribution Energy Networks Association (Association of PES Licence Holders) High Voltage - AC Voltages above 1000V: generally refers to supplies at 6.6 or 11kV but may include supplies at higher voltages Independent Distribution Network Owner Licensed Inset Network Owner/Operator Privately owned electricity supply network, owned and operated by a licensed IDNO, supplied at a boundary point or points from the DNO Network. Licensed Distribution Network Operator - the holder of a Licence to distribute electricity Long Term Development Statement Low Voltage - AC Voltages between 50 and 1000V: generally refers to single or three phase supplies at 230/400V. The Network Operator whose assets in the particular substation represent the highest total capital installation cost. UK Power Networks Network Asset Management Plan (UK Power Networks Standard CAP ) Part of the new connection works which can only be undertaken by UK Power Networks and includes design approval, obtaining statutory consents, inspection of the works, and work on the existing UK Power Networks Distribution System. Office of Gas & Electricity Markets (Regulator) Point of Connection The point determined by UK Power Networks where the new load is to be connected to its Network. Point of Supply The point of supply for the IDNO network from the DNO network and is the network Ownership Boundary. UK Power Networks 2015 All rights reserved 5 of 30

6 Primary Substation RMU RTU SCADA SOP Statement of Basis and Methodology of charges for Connection to the Electricity Distribution System UoS (Main Substation in LPN) Transformation and switching point that supplies 11kV or 6.6kV Networks from the higher Voltage EHV Network. Ring Main Unit Radio Telecontrol Unit Supervisory Control and Data Acquisition Suspension of Operational Practice Document dated 1/11/2010. Includes the connection Charge Statement which provides the basis of charges for the provision of a connection and the Connection Charging Methodology which describes the methodology under which Customers will be charged for a connection to UK Power Networks. Use of System (Charges) UK Power Networks 2015 All rights reserved 6 of 30

7 4 Planning Guidelines The following considerations are relevant when planning the connection of an inset network. The IDNO should specify the site to be supplied, the demand and the load characteristics to be met. If no site (or location for the start of the IDNO network) is specified, under s16a of the Electricity Act 1989 a request for terms of connection cannot be deemed to have been submitted. The Point of Connection (POC) assessment is non-contestable and is therefore to be determined by UK Power Networks in all cases. The Point of Supply (POS) also known as the network Ownership Boundary must be defined and will not necessarily be at the POC (Responsibility for Deed of Grant / Easements must be established and confirmed.) but will require as a minimum a single isolation/protective device to be installed in compliance with Regulation 6 of ESQCR. The boundary equipment, if not built by UK Power Networks, must be specified to comply with our approved equipment requirements (ER G81 pt. 2) as it will be adopted by UK Power Networks. Earthing arrangements for equipment to be adopted must comply with UK Power Networks Engineering Design Standards for earthing (EDS to EDS ) as appropriate. A minimum cost scheme must be identified. Connection charges shall be determined in accordance with the current version of UK Power Networks Connection Charge Statement and Methodology. Where multiple supplies are provided to an inset network, either at the IDNO s request or as the minimum cost scheme, agreement must be reached on precautions required to prevent, or to allow parallel operation of incoming supplies. The decision to whether or not allow parallel operation rests with UK Power Networks and shall be referred to UK Power Networks Asset Management. Where transfer of load between supplies is permitted this shall be clearly defined in a written agreement. UK Power Networks is required by OFGEM to meet prescribed levels of performance against the following three key non-contestable areas of work as specified in SLC15 (Standard Licence Condition 15): Provision of quotations including Point of Connection (POC). Design approval or reasoned objection. Completion of final connections/phased energisation. 4.1 IDNO to Specify Site Location and Demand As a general principle any customer is required to provide details of the premises to be supplied (i.e. the point to which the supply is to be delivered), when the supply is required and, to the best of their knowledge, the anticipated maximum demand in terms of magnitude and type. Electrical characteristics relating to disturbing loads and generation are required to be provided in accordance with ER G88 (paragraph 3.3). An IDNO may be seeking to supply a general area, but the requirement remains, under Section 16A of the Electricity Act, for the IDNO to specify the location of its connection in seeking terms from UK Power Networks (the DNO). If the IDNO information is not accurate or specific then the basis for UK Power Networks making an offer of terms for connection may be invalidated. The IDNO s POC may be considered higher up the system than would perhaps be the case if needed solely for a specific site. An IDNO might also quote a speculative demand figure that is not based on a specific site but an anticipated aggregate demand within a larger geographical area. UK Power Networks 2015 All rights reserved 7 of 30

8 In responding to such speculative enquiries UK Power Networks can only provide technical information limited to that of the available capacity in the area, the connection voltage, a budget cost and system characteristics based on an assumed point of connection (POC). In the case of a non-specific enquiry no agreement will be entered into that indicates or implies that the network Ownership Boundary will be at any specific location. The following diagram clarifies the distinction between the POC and the network Ownership Boundary. The choice between a local, intermediate or remote POC will be determined by the capability of the DNO s network to accept the demand. Larger demands in general requiring more remote POC s UK Power Networks Primary (Main) Substation Intermediate POC Local POC UK Power Networks Existing Main Remote POC Initial IDNO Customer Site Network Ownership Boundary (see Sec 3) Figure 1 POC Options in Relation to a Connection Boundary In figure 1 above, single connections are shown for clarity; the actual arrangements shall comply with UKPN EDS Point of Connection The Point of Connection (POC) is the point (or points) on the UK Power Networks electrical network to which the new assets will be connected. The point of connection is currently noncontestable. The IDNO will identify to UK Power Networks the preferred location of the Point (or points) of Supply (POS) and unless commercially sensitive the IDNO shall inform UK Power Networks of all known requirements including the future anticipated required capacity for the development. Wherever reasonably practicable, UK Power Networks shall ensure that the POS meets the requirements of the IDNO. They are entitled to choose from options that may be presented to them by UK Power Networks. Normally the POC will be as close as practicable to the inset network, this will in most cases be the cheapest way of providing the connection required by the IDNO. The POC shall be determined by UK Power Networks taking into account all the IDNO s requirements and UK Power Networks wider obligations. In specifying the POC the decision should be based on the same considerations that would be made if the site were being connected directly by UK Power Networks as the resident DNO. UK Power Networks 2015 All rights reserved 8 of 30

9 Nothing in the foregoing shall preclude the choice of a POC that is not minimum cost where UK Power Networks, in accordance with the UK Power Networks Connection Charging Statement and Methodology, wish to include a non-chargeable reinforcement element in the project, or where the IDNO requests a different POC and agrees to pay the additional marginal costs in full plus operation repair and maintenance charges. It should be noted, however, that agreement to an IDNO s request for a different POC remains at the reasonable discretion of UK Power Networks and may be declined if it would be detrimental to the efficient future development of the distribution network. Also, the POC need not be the network ownership boundary and negotiations on POC should not be confused with those relating to the location of the network ownership boundary. UK Power Networks Primary (Main) Substation Local POC UK Power Networks Existing Main Initial IDNO Customer Site Network Ownership Boundary (see Sec 3) Figure 2 Example of a local POC UK Power Networks Primary (Main) Substation IDNO s Requested POC Minimum Cost POC UK Power Networks Existing Main Extra Route Length Initial IDNO Customer Site Network Ownership Boundary (see Sec 3) Figure 3 IDNO Request for a More Remote POC In most cases a ring connection would be required and would be the minimum cost scheme. If the POC were moved to a more distant location at the request of the IDNO, the minimum engineering scheme would still be a ring connection. Refer to EDS UK Power Networks 2015 All rights reserved 9 of 30

10 4.3 Standard Planning Details ENA Engineering Recommendation G88 Section 3 describes the standard planning details that are required from the IDNO (Section 3.3) and from UK Power Networks as the DNO (Section 3.4). UK Power Networks shall provide the required details (as appropriate) listed in Section 3.4 of G88 in response to the details that must be provided by the IDNO as listed in Section 3.3.of G88. For a POS at Low Voltage this shall include the following which shall be obtained by UK Power networks using an LV network design programme (currently WinDebut): Anticipated design voltage drop as a percentage of declared voltage at the POS. Anticipated prospective short circuit fault current at the POS. Circuit Loop Impedance based on unity power factor at the POS. UK Power Networks 2015 All rights reserved 10 of 30

11 5 Network Ownership Boundary 5.1 General Electrical Arrangements The network ownership boundary shall be located as close to the inset network as practicable to allow UK Power Networks to use its assets economically for possible future connections or system improvement. Boundary equipment providing isolation and ESQCR Regulation 6 protection shall be located at the network ownership boundary and be provided or adopted, at each voltage level, by UK Power Networks. Where boundary equipment is not included in the initial design, adequate space adjacent to the EHV side of the inset network supply shall be provided to accommodate future installation. Should additional equipment be required, this equipment shall be owned by UK Power Networks and the outgoing terminals shall form the ownership boundary. The phase rotation on any IDNO LV network shall match the rotation on the local network within UK Power Networks. Where the existing network within UK Power Networks has nonstandard phase rotation UK Power Networks and the IDNO shall agree the solution for phase rotation for the proposed inset network. This agreement shall be in writing and included with the other written agreements for the site. It is the responsibility of the IDNO to comply with ENA ER P2/6 requirements for their network. In addition to locking arrangements label EDS shall be displayed in respect of the network Ownership Boundary equipment (e.g. circuit-breaker, link box or cut-out). 5.2 Boundary Access Arrangements Grid and Primary sites Shared access to these complex sites will not normally be granted because of the many issues it raises in respect of legal, security and safety issues. Shared Access arrangements to other sites shall be agreed and documented by an Ownership and Responsibilities schedule within the Connection Agreement between the IDNO and UK Power Networks and shall include the following areas: Safety aspects operational competencies, control procedures etc. Plant Specifications including defect notification to/from IDNO/UK Power Networks. Building Design. Access/Egress. Legal. Special Factors. 5.3 Boundary Equipment Unnecessary duplication of boundary equipment must be avoided, unless this is impracticable because of the need to comply with Regulation 6 of ESQCR. This implies an optimisation of assets at the boundary and there will be a necessity to agree the basis on which parties may work upon or operate boundary equipment which belongs to the other party. UK Power Networks 2015 All rights reserved 11 of 30

12 The choice of equipment shall be consistent with the operation of the local network design Standard including any necessary automation or remote control equipment, where required. If equipment is provided as contestable work, it shall be in accordance with UK Power Networks G81 pt. 2 Materials Specification Listing. Any installations undertaken by the IDNO or its appointed agent/accredited ICP under Competition in Connections (C I C), for adoption by UK Power Networks, shall comply with the G81 requirements and procedures. The work shall be carried out by a Lloyds accredited ICP (which may include the IDNO). All contestable (C I C) work carried out to install assets to be adopted by UK Power Networks shall be audited in accordance with UK Power Networks Standards (CON and EDS internal only) Boundary Metering OFGEM s revised decision on boundary metering (2 nd March 2010) introduced portfolio billing, from 1 st April 2010 and removed the requirement for IDNOs to pay for boundary metering. In removing the requirement for IDNOs to pay for the metering, OFGEM placed the responsibility for payment and the decision whether or not to meter at the network boundary with the DNOs. Provision of metering at Network Boundary (UK Power Networks decision dated October 2011): For LV boundary - No metering will be installed. For HV boundary No metering will be installed. For 132kV/EHV boundary - Metering shall not be installed after 1 st April Data from existing metered installations may be used to check the accuracy of the portfolio billing system. UK Power Networks 2015 All rights reserved 12 of 30

13 6 Connections 6.1 Low Voltage Cable Network Connection Standard LV Service Arrangement: A standard LV Service supply arrangement can be provided in accordance with UK Power Networks EDS for underground services up to 100A and for large LV supplies in accordance with EDS ENA Engineering Recommendation G87 issued in January 2010 gives details for Provision of LV Connections to Multiple Occupancy Buildings. Subject to appropriate Competencies and written agreement the IDNO, staff may be given access to the UK Power Networks cut-out fuses/links to enable them to restore supplies in the event that a fault on their system causes the operation of the cut out fuses. If the arrangement comprising two sets of LV cut-outs in a pillar or meter box is deployed, the UK Power Networks cut-out shall contain links and IDNO cut-out fuses Standard LV Supply Interface at Fuse Cabinets, Feeder Pillars and Link Boxes The preferred method to connect an IDNO network at LV is by the use of a link box as the boundary isolation/protective device, this is restricted to the maximum link box rating and fuse rating available to be fitted to the link box. An earth electrode will be required at the end of the UK Power Networks LV main e.g. at the incoming side of the link box in accordance with the UK Power Networks Engineering Design Standards for earthing (EDS to EDS ) as appropriate. For new LV network connections, UK Power Networks shall own or adopt the link box. 6.2 HV Supply from Networks owned by UK Power Networks There are two basic requirements: UK Power Networks provides an HV connection to a single IDNO transformer. UK Power Networks provides one or more HV connections to an IDNO HV network. And these requirements can be satisfied by installing and commissioning: One or more HV Ring Main Units with RTUs to be commissioned at the time of installation in accordance with EDS Automation. One or more HV single non-extensible circuit-breakers. An extensible switchboard. Where UK Power Networks provides or adopts an HV supply to a single IDNO transformer using a close coupled RMU or CB, the ownership boundary shall be as shown in Figure 4. UK Power Networks 2015 All rights reserved 13 of 30

14 Actual POC UK Power Networks Existing Main Protection Switchgear Network Ownership Boundary p IDNO Transformer & LV Fuse Cabinet IDNO Site Owned or Leased UK Power Networks Existing UK Power Networks New IDNO Assets Figure 4 Network Ownership Boundary Arrangements for IDNO Transformer Connection The IDNO shall have the option to design procure and install the full RMU substation including the building/housing, following the requirements and procedures under Engineering Recommendation G81 for the following: HV Ring main unit or HV single non-extensible circuit-breaker. HV cable tails to point where they meet the existing UK Power Networks HV ring (The closing joint is to be made by UK Power Networks or by an ICP acting as a contractor to UK Power Networks and under UK Power Networks operational control). Substation earthing. The RMU (subject to G81 conformity) shall be adopted by UK Power Networks in order to retain full ownership and control of UK Power Networks HV ring to which the substation is connected. Unless otherwise agreed, responsibility for the building/enclosure shall be accepted by the Majority Asset Owner. The ring switches on the RMU shall have UK Power Networks operational locks and the teeoff CB may be covered by dual locking. Any operations shall be in accordance with UK Power Networks Distribution Safety Rules (DSRs) and to the instructions of UK Power Networks Control Engineer. Agreement to permit the IDNO staff to operate the tee-off CB shall depend upon the IDNO staff holding appropriate UK Power Networks authorisation. The decision to enter such an agreement shall be by joint agreement with UK Power Networks and shall be formally documented. UK Power Networks 2015 All rights reserved 14 of 30

15 Where no operational agreement is made, an emergency trip only arrangement shall be provided at the IDNO s cost as a means to cutting off the supply as required by Regulation 12 of the Electricity at Work Regulations. The IDNO has the option to positively opt out of the requirement to install such an arrangement this option shall be included in the offer letter to which the IDNO can respond in writing should they wish to opt out. Where an emergency trip is provided at an approved location this shall be in accordance with EDS Because of the requirement to agree a minimum overall cost scheme, DNOs and IDNOs agree that joint access to a single substation enclosure will be the standard arrangement. Bus Section Circuit-breakers shall not be used by UK Power Networks to connect customer supplies and only cable connections shall be provided. This will avoid unnecessary complications where asset alteration or replacement may be required in the future. Actual POC UK Power Networks Existing Main Protection UK Power Networks controlled Zone (Owned, Leased or Sub- Leased to UK Power Networks) UK Power Networks Switchgear Suitable Partitioning Screen IDNO Controlled Zone Network Ownership Boundary p UK Power Networks Existing UK Power Networks New IDNO Assets IDNO Site Owned or Leased Emergency Trip Figure 5 Switchgear Arrangements at the Network Ownership Boundary, for Situations where no Operational Agreement Exists for IDNO Staff to have Access to UK Power Networks Controlled Equipment UK Power Networks would not normally need access to the transformer or LV cabinet for operational requirements but may require access to the lighting and socket outlet facilities provided by the IDNO. Whatever the operational agreement, the maintenance responsibility for any UK Power Networks owned/adopted switchgear or switchboard shall remain with UK Power Networks. UK Power Networks 2015 All rights reserved 15 of 30

16 6.2.1 HV Circuit Connection An IDNO is treated as a single customer by UK Power Networks for the purposes of assessing compliance with P2/6. Guidance Note 1 of the Distribution Code states that P2/6 does not apply to individual customers. This means that by treating it as a single customer in accordance with UK Power Networks Engineering Instruction EDS design criteria the minimum cost engineering scheme could be a single circuit connection to an IDNO, in that case the IDNO has the option to request a higher level of security. However in most cases the connection will be a looped supply from a ring main unit. For a larger network, it might be necessary to afford multiple connections. A single supply could comprise of more than one HV circuit in order that the IDNO may meet its own ER P2/6 and Licence Condition 5 obligations. An IDNO operating a network with multiple customers may have no option other than to provide an adequate level of supply security to comply with P2/6, even though UK Power Networks would have no such obligation for an IDNO site (as a notional single customer). A distinction needs to be made at this point between the provision of multiple connections to allow the IDNO to meet its security of supply obligations and the use of multiple connections to avoid reinforcement costs by splitting the demand or to comply with minimum design standards. The UK Power Networks Common Connection Charging Methodology Section 5 gives various cost apportionments and connection charges with examples. The IDNO can achieve P2/6 compliance if two RMU s (the boundary switchgear) are connected into a single feeder, as shown in Figure 6. From a UK Power Networks perspective this does not present any undue operational liabilities. UK Power Networks HV Network IDNO Duplicate circuits from two RMU s off a single feeder allow the IDNO to meet its P2/6 obligations within the inset network. Note two adjacent tees will not satisfy the requirement IDNO Duplicate circuits from separate feeders will introduce operational constraints and complicate control procedures Figure 6 Possible Arrangements for Multiple HV Connections to the IDNO UK Power Networks 2015 All rights reserved 16 of 30

17 An alternative would be to provide connections from two different feeders. There would then be the potential for the IDNO to parallel the UK Power Networks connection points through its network, or to move significant demand from one connection point to another. Before this kind of arrangement is used, safeguards will need to be agreed between the IDNO and UK Power Networks clearly stating how the network will be operated. In circumstances where more than one IDNO is connected to a group of feeders, each with the capability to interact with the network within UK Power Networks in the way just described, it must be recognised that the resulting control and operation of the network will be more complex because of the involvement of multiple control centres. The provision of multiple connections shall be subject to a design and operational assessment of the specific circumstances. Suitable controls will be required and operational regimes will need to be agreed and documented, as will any network constraints that limit the amount of demand that can be supplied from each connection point. Such constraints may relate to UK Power Networks normal network and/or an emergency configuration and any automation scheme. Where an IDNO requests multiple connections to provide alternative supplies to its customers, or specifically to comply with P2/6, the application shall be treated in the same way as that from any other customer who has specific supply security requirements. Designs shall be in accordance with current Standard for multiple supplies to a Single Building or Customer (See also EDS kV Distribution Network Design Standard and EDS Provision of HV Connections with Higher than Normal Security). All connection charges shall be in accordance with UK Power Networks Common Connection Charging Methodology HV Substation Connection The IDNO shall be responsible for ensuring adequate system earthing arrangements, including provision of bonding to the adjacent DNO systems and neutral earthing in accordance with UK Power Networks Engineering Design Standards for earthing (EDS to EDS ) as appropriate. The design shall suitably limit step, touch and transfer potentials, and ensure earthing components have adequate thermal rating. Actual POC UK Power Networks Existing Main Protection Switchgear Supply Terminals Network Ownership Boundary p IDNO Site Owned or Leased Figure 7 HV Substation Arrangement UK Power Networks 2015 All rights reserved 17 of 30

18 For each supply point a Site Operational Responsibility Schedule, as is described in Engineering Instruction CON , shall define the authority to operate designated switches and responsibilities for maintenance and repair. This shall include responsibility for protection equipment and any emergency trip feature and structures. In addition there shall be on site a diagram showing operational responsibilities and contact details for all those party to the Site Responsibility Schedule. 6.3 EHV/Primary Substation Connection Providing a supply to an inset network direct from a primary substation (or in LPN {Region 1} a main substation) introduces a number of safety, technical and cost considerations. The desire to avoid duplicate boundary equipment could lead to a request to treat the primary substation circuit-breaker(s) as the boundary switchgear. Dedicating the circuitbreaker(s) in this way may not generally be an efficient and effective use of the primary substation assets. However, UK Power Networks will permit this arrangement in appropriate circumstances in consideration of: The level of the capacity requirement in relation to the capacity of the assets. The availability of space for the necessary equipment. Any future planned works at the site. Legal requirements (see section Legal). Where none of the above considerations would preclude use of the primary substation circuit-breakers as the boundary switchgear, then this arrangement will be permitted. The boundary switchgear located at a primary substation shall always be under the ownership and operational control of UK Power Networks utilising Remote Control/Automation as required (refer to UK Power Networks EDS ). The IDNO shall provide the HV cable to terminate on the boundary switchgear. IDNO staff will not be provided with general access to the substation site and shall not operate the boundary switchgear. Access for IDNO staff to work on the IDNO cable shall be subject to established third party access procedures in accordance with UK Power Networks Distribution Safety Rules. When isolation and earthing is required, this shall be carried out by the owner of the relevant asset and an appropriate safety document issued across the control boundary. See UK Power Networks Distribution Safety Rules (Code of Practice 4 refers). There will be different charging scenarios for each case, and while the option that fully integrates the IDNO Network with the network within UK Power Networks by providing optimum use of switch panel positions is to be preferred, any increased cost to the UK Power Networks infrastructure budget as a result of adopting this efficient use of assets option will need to be considered internally within UK Power Networks in relation to its benefit relative to other infrastructure schemes in the programme and the available budget. UK Power Networks 2015 All rights reserved 18 of 30

19 IDNO Inset Network IDNO Inset Network Dedicated Feeder Option Local Network Reinforcement Option Figure 8 Optimum use of Switch Panels at a Primary Substation UK Power Networks 2015 All rights reserved 19 of 30

20 7 Building Design, Civil Works and Legal Aspects 7.1 Building Design Access and Egress Arrangements In some instances, such as where supply is afforded from an RMU, shared access will be necessary if the IDNO is able to operate the circuit-breaker(s) controlling its inset network. In these circumstances building design considerations largely involve ensuring that there is acceptable access and egress in respect of both plant and personnel, that safety distances are maintained and that the fabric of the building is to an acceptable standard. UK Power Networks requirements for access and egress must be included at the design stage and agreed by all relevant parties. The owner of the building/enclosure shall hold the site duties under the ESQCR and their name and 24 hour telephone number shall be displayed on the door as the site owner. (This is the only telephone number to be displayed). The name of all other owners of plant and equipment in the substation must also be displayed on the door. Shared access to a boundary substation will normally mean the provision of suitable dual locking facilities. In such circumstances the IDNO could still enter shared access arrangements in respect of the controlling HV switchgear, subject to all personnel involved having the correct competency for the task and the conditions already described. However, its need to enter the HV switchroom would need to be limited to essential operations Civil Works Substations Where the majority asset owner is UK Power Networks the design and construction of the substation building or housing and bases shall be to UK Power Networks standard or approved alternative. The Network Operator who will have responsibility for the substation building/enclosure shall ensure that adequate ventilation is provided and maintained to ensure the design rating of all the electrical equipment in the substation is safeguarded. UK Power Networks substations require 24-hour access for personnel and plant, access that can be utilised at short notice in the case of an emergency. In situations where special emergency escape is required these shall be met to the satisfaction of UK Power Networks. The normal location for a substation, whether in a separate building or integral to a customer owned building, is at ground level and shall be in accordance with UK Power Networks EDS Secondary Substation Civil Design Standard. The design for this shall ensure Supply Security and Operational Health and Safety aspects are fully included in the design and all as defined in ER G81 part1 section 7.9 and EDS Legal All necessary consents relating to the substation or switchroom shall normally be obtained by the IDNO. However, if the substation or switchroom is to provide a strategic purpose additional to that of being a supply point for the IDNO, for example the housing of tee-point switchgear, then UK Power Networks will need to ensure that its interests are adequately protected by the agreed tenancy arrangements. UK Power Networks 2015 All rights reserved 20 of 30

21 The rights for the cable route from the point of connection to UK Power Networks network to the boundary equipment will need to be obtained by UK Power Networks or by the IDNO on behalf of UK Power Networks, as these circuits will ultimately form part its network. All easements, wayleaves or other legal agreements shall be completed to the correct UK Power Networks standard. In situations where it is agreed that boundary equipment can be located within an existing site occupied by UK Power Networks (e.g. a Distribution or Primary substation) then the terms of any existing tenancy agreement will need to be consulted, as it is possible that it will preclude the granting of rights to another party without the landlord s consent. If the IDNO can secure a tenancy or wayleave/easement then UK Power Networks consent cannot be reasonably withheld, although it is important that UK Power Networks moves to act as an intermediary in any such negotiations between the IDNO and the landlord. If such an arrangement is agreed within a primary substation, the IDNO s equipment must be housed within a separate curtilage with independent access arrangements. The IDNO will need to negotiate with any third party landlord or owner for all necessary rights to install and maintain its cables. UK Power Networks 2015 All rights reserved 21 of 30

22 8 Minimum Cost Scheme, Apportionment and Network Optimisation The minimum cost scheme will be one that meets the requirements of the IDNO, is technically compatible with UK Power Networks network/design standards and follows the Common Connection Charging Methodology and Statement. There may be the opportunity to enhance the network within UK Power Networks in association with the connection scheme and any apportionment of cost to the IDNO being subject to and in accordance with the UK Power Networks Common Connection Charging Methodology. This is an important principle that aligns with the approach that we take for all new connections, and which is a natural consequence of a robust POC assessment carried out within UK Power Networks Asset Management. Reference shall be made to the Examples of reinforcement apportionment shown in the UK Power Networks Common Connection Charging Methodology Section 5. UK Power Networks will also consider any opportunity for Network Optimisation using the standard internal NAMP process. To ensure that the UK Power Networks design proposal (including plant specification) meets the minimum cost scheme criteria it will be necessary to demonstrate that it is essential for the efficient and effective operation of UK Power Networks network. The design proposal shall comply with UK Power Networks strategic development plans, its design policies and the Common Connection Charging Methodology and Statement. The Connection Charging Methodology document has been approved by the Gas and Electricity Markets Authority (the Authority ) and the Connection Charging Statement the form of which has been approved by the Authority. UK Power Networks 2015 All rights reserved 22 of 30

23 9 References CAP CAP NAMP Development Process Overview. NAMP Change Control Process. CDM Construction (Design Management) Regulations CON D-Code DSRs EDS EDS EDS EAS Competition in Connections final connection and phased energisation procedure. The Distribution Code of Great Britain OFGEM Agreed Publication. UK Power Networks Distribution Safety Rules. Earthing Design Criteria. Customer Installation Earthing Design. Secondary Substation Civil Design Standard. Signs and Labels for Operational Sites & Equipment EDS Audit and Inspection Standard for Connection Providers. EDS EDS EDS EDS EDS kv Distribution Network Design Standard. System 8 Network Design Guidelines Central London. Remote Control/Automation of Distribution Switchgear. Loading of Secondary Distribution Transformers. Guidance for the Application of ENA Engineering Recommendations G88 and G81 - Inset Networks (IDNOs and Guidance for the application of ENA engineering recommendation g88 and g81 - inset networks (IDNOs and other licensed DNOs). EDS Underground services up to 100A. EDS EDS EDS System 4 Network Design Guidelines Central London. Planning Requirements for Distribution Substations. Customer LV supplies (above 100Amp Single phase). UK Power Networks 2015 All rights reserved 23 of 30

24 EDS Emergency Trip Button Electricity Act Electricity Act 1989 as amended by the Utilities Act 2000 and the Distribution Code which is given legal authority by the provisions of the Public Electricity Supply Licence issued under it. Electricity at Work Electricity at Work Regulations ENA ER G12/3 ENA ER G14 ENA ER G39/1 ENA ER G5/4-1 ENA ER G59/2 ENA ER G74 Requirements for the application of protective multiple earthing to low voltage networks. Protective multiple earthing recommended principles of testing to ensure correct polarity. Model code of practice covering electrical safety in the planning installation commissioning and maintenance of public lighting and other street furniture. Planning levels for harmonic voltage distortion and connection of non-linear equipment to transmission and distribution networks in the UK. Recommendations for the connection of embedded generation plant to the public electricity suppliers distribution systems. Procedure to meet the requirements of IEC 909 for the calculation of short circuit currents in three-phase AC power systems. ENA ER G81/1 Framework for design and planning, materials specification, installation and record for low voltage housing development installations and associated new HV/LV distribution substations Part 1 Design and Planning. ENA ER G81/2 Framework for design and planning, materials specification, installation and record for low voltage housing development installations and associated new HV/LV distribution substations Part 2 Materials. ENA ER G87 ENA ER G88 Guidelines for the Provision of Low Voltage Connections to Multiple Occupancy Buildings. Principles for the Planning, Connection and Operation of Electricity Distribution Networks at the interface between Distribution Network Operators (DNOs) and Independent Distribution Network Operators (IDNOs). UK Power Networks 2015 All rights reserved 24 of 30

25 ENA ER P17 ENA ER P2/6 ENA ER P25/1 ENA ER P26 ENA ER P28 ENA ER P29 ESQCR License condition Management of health and safety Current rating guide for Distribution Cables. Security of Supply. The short circuit characteristics of PES LV distribution networks and the co-ordination of over-current protective devices on 230v single phase supplies up to 100A. The estimation of maximum prospective short-circuit current for three phase 415V supplies. Planning limits for voltage fluctuations caused by Industrial, Commercial and Domestic equipment in the United Kingdom. Planning limits for voltage unbalance in the United Kingdom 132 kv and below. Electricity Safety Quality and Continuity Regulations 2002, as amended 2006 (and associated guidance issued by DTI). Distribution Licence Conditions OFGEM Agreed Publication. The Management of Health & Safety at Work Regulations Safety at work Health & Safety at Work Act UK Power Networks 2015 All rights reserved 25 of 30

26 Appendix A Supportive Information and Historical Reference Documents A.1 UK Power Networks Internal Inset Network Procedure A.1.1 UK Power Networks Quality Process [AST ] 25/10/2004 AST is the internal ISO9001 process for managing applications for inset networks within UK Power Networks. The document defines contestable and non-contestable connection works, and the term inset network. It also defines two types of inset network applications: indicative and formal. Budget cost These are considered as speculative enquiries, the response to which is nonbinding and provided free of charge. A notional half-day (maximum) assessment period is assumed. Formal quotations A chargeable assessment is carried out in line with the rates specified elsewhere in the document. In both cases the normal point of connection procedure is followed with referral of qualifying demands to UK Power Networks Asset Management (Distribution Planning). A.2 Regulation of Independent Electricity Distribution Network Operators A.2.1 OFGEM decision document 176/05 July 2005 This document sets out OFGEMs decision on the appropriate long-term regulatory regime for new independent distributing network operators (IDNOs), and incumbent DNOs operating outside their distribution service areas. This is a long document although Section 4, which considers Commercial Arrangements, is the most relevant to these guidelines. In particular, it considers boundary equipment and boundary metering. A.2.2 Boundary Equipment OFGEM acknowledges that to satisfy Regulation 6 of the ESQC Regulations Distributors have to fit protective devices to their networks, meaning that a fuse or a circuit-breaker will have to be fitted at each point of connection. OFGEM expect that in most cases this would be achieved by a single protective device, not separate devices operated by the DNO and IDNO respectively. OFGEM further state that the HSE support the view that in most cases two circuit-breakers may not be necessary to meet the requirement of ESQCR, while noting that there may be exceptions to this, and each case should be considered to ensure that parties are satisfied that they meet the requirements of the Regulations. UK Power Networks 2015 All rights reserved 26 of 30

27 OFGEMs summarised views are: In many circumstances this should mean that only one set of isolation equipment should be necessary. There may be exceptional circumstances where licensees can justify the provision of duplicate sets of protection equipment. Where one set of isolation equipment is used it must be provided in a manner that enables both licensees to have reasonable access. Where one set of isolation equipment is used licensees shall cooperate to reach reasonable commercial arrangements that provide access and assign responsibility for operating, maintenance and replacement. The IDNO shall pay for the isolation equipment at the interface although, in general, it shall only be expected to pay for one set of equipment. A.2.3 Boundary Metering OFGEM Decision Document 29/10 March 2010 On 2nd March 2010 OFGEM published its decision on the subject of boundary metering. Extracts from this document are reproduced below. The proposed approach to billing IDNOs in the recently approved DNO common charging methodology should provide DNOs with a mechanism for doing this. The CDCM requires DNO to bill IDNOs on a portfolio basis. This means they will be billed according to the capacity/commodity characteristics of each customer they have connected to their networks rather than the aggregate characteristics of the sites that they have adopted. To enable portfolio billing a modification (P246) to the BSC has recently been approved. This modification enables Elexon to provide settlement data from customers connected to IDNO networks to the upstream DNO for the purpose of calculating use of system (UoS) charges. One impact of this modification is that DNOs do not need to measure flows across the boundary between itself and individual IDNO sites in order to bill IDNOs. Portfolio billing will be introduced from 1 April We therefore consider that the change in policy on boundary metering will come into force from this date. In our October consultation we suggested that if the portfolio billing solution that was put in place required the functionality to reconcile between settlement data and recorded flow by boundary meters then it would seem appropriate that the DNOs pay for the costs of the billing solution. However, we have since noted that the reconciliation function of the billing system only marginally increases the complexity of the proposed system and that reconciliation may be necessary if a sample of boundary meters is to be used. If DNOs and IDNOs agree that some sample of metering and reconciliation is required, then it would seem appropriate that the associated costs of the billing system are split between DNOs and IDNOs on a per licensee basis. This decision document confirms the proposal in our October 2009 consultation to change OFGEM's policy regarding the regulatory treatment of metering at the boundary between DNO and IDNO networks. Our revised position is that the DNO shall be responsible for deciding the solution that is required and paying the costs associated with the solution and its installation. This guidance is intended to provide an indication to affected parties as to our starting position in any dispute between a DNO and IDNO regarding boundary measurement received after 1 April notwithstanding the fact that each dispute will be considered on a case by case basis. UK Power Networks 2015 All rights reserved 27 of 30