EDS LV CUSTOMER UNMETERED SUPPLIES

Transcription

1 Document Number: EDS Network(s): Summary: ENGINEERING DESIGN STANDARD EDS LV CUSTOMER UNMETERED SUPPLIES EPN, LPN, SPN This standard details the requirements for unmetered single-phase LV supplies on the public highway and ensures the electricity supply to unmetered street furniture is designed to optimise safety, cost and network reliability. Author: Stephen Cuddihey Approved By: Paul Williams Approved Date: 20/12/2017 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. Circulation UK Power Networks External Asset Management G81 Website Capital Programme UK Power Networks Services Connections Contractors Health & Safety ICPs/IDNOs Legal Meter Operators Network Operations Procurement Strategy & Regulation Technical Training THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE

2 Revision Record Version 9.0 Review Date 20/12/2022 Date 13/11/2017 Author Stephen Cuddihey Reason for change: Re-alignment of LV design standards. What has been changed: References to LV design standards updated throughout, review date extended to match suite of documents Version 8.0 Review Date 09/03/2022 Date 23/02/2017 Author Stephen Cuddihey Reason for change: Document reviewed and updated following consultation with Customers and Highway Services. What has been changed: Section 6.3 reviewed to correct table 4 disparity. Section 6.4 reviewed to clarify asset movement distance. Section 6.6 amended for fifth core transfer to phase core. Section 6.7 amended for PVC SWA cables. Document renumbered from EDS to EDS Version 7.0 Review Date 09/08/2021 Date 09/08/2016 Author Stephen Cuddihey Why has the Document been changed: Document reviewed and updated following consultation with Highway Services. What has been changed: All sections thoroughly revised and structure updated. Various requirements clarified and guidance included on common issues. Document tile amended Version 6.0 Review Date 01/01/2019 Date 31/12/2015 Author Stephen Cuddihey Why has the document been updated: Review for UMC ICP Trial project in relation to EBP What has changed: Section 6.8 added for UMC supplies from overhead line guidance. Section 7.4 added for existing supplies from overhead line guidance. Section amended to avoid duplication of statements in new section. Section added for disconnection from overhead line guidance. Version 5.0 Review Date 21/05/2017 Date 21/05/2014 Author Stephen Cuddihey Review of G39 and overhead line UMC disconnection Version 4.0 Review Date 23/04/2014 Date 25/02/2013 Author Stephen Cuddihey Review of maximum power, disconnections and 5 th core works charging. UK Power Networks 2018 All rights reserved 2 of 18

3 Version 3.1 Review Date 25/02/2013 Date 17/07/2012 Author Lee Strachan Reviewed for publishing on G81 website Version 3.0 Review Date 25/02/2013 Date 29/02/2012 Author Ron Cordwell VIR insulated lead sheathed SWA cables added. Amendment to section Multiple Street Furniture Connections Version 2.0 Review Date 29/02/2012 Date 11/05/2011 Author Ron Cordwell Information for Customers has been added to the front page UK Power Networks 2018 All rights reserved 3 of 18

4 Contents 1 Introduction Scope Glossary and Abbreviations Supplies Overview New Unmetered Supplies Overview Standard Supply Looped Supplies Supplies in Excess of 500W Supplies at Inaccessible, Third Party Owned or Dangerous Locations Existing Supplies Overview Transfer of Supplies Relocation of Supplies Existing Looped Supplies Existing Unmetered Three-phase Supplies Existing Fifth Core and Switched Supplies Historic Cables and Cut-outs with Operational Concerns General Requirements Earthing Intake Position Legal Requirements Temporary Disconnection Disconnection Documentation Certificate to Confirm Unmetered Supply Energisation Certificate to Confirm Unmetered Supply De-Energisation References UK Power Networks Standards National and International Standards Dependent Documents Tables Table Maximum Earth Fault Loop Impedance for fuse selection UK Power Networks 2018 All rights reserved 4 of 18

5 1 Introduction This standard details the requirements for unmetered single-phase LV supplies on the public highway and ensures the electricity supply to unmetered street furniture is designed to optimise safety, cost and network reliability. Unmetered supplies are defined as assets with the following criteria: Within the provisions of SI 2001 No The Electricity (Unmetered Supply) Regulations in relation to a maximum load for individual items (normally 500W). The cumulative load of multiple individual items from the supplying connection does not exceed 2000W. The usage is predictable in load and operation. The asset connected or to be connected to the relevant exit point has a national charge code issued by Elexon (unless otherwise expressly authorised by the DNO s unmetered supplies operator). All queries regarding unmetered supplies within the UK Power Networks distribution network areas shall be referred to the Highway Services or Unmetered Supplies Operator teams within UK Power Networks. 2 Scope This standard applies to unmetered single-phase LV supplies on the public highway. Single-phase LV supplies of a maximum power requirement greater than 2kW are not covered within this standard; refer to EDS Metered three-phase LV supplies are not covered within this standard; refer to EDS HV supplies with or without boundary metering are not covered within this standard; refer to EDS EHV supplies with or without boundary metering are not covered within this standard; refer to EDS Unmetered supplies shall not be offered to a multi-occupied building; refer to EDS UK Power Networks 2018 All rights reserved 5 of 18

6 3 Glossary and Abbreviations Term Definition Asset CNE EHV HV ICP For the purposes of this standard, asset refers to any unmetered equipment, defined by Elexon as any electronic equipment that draws a current and is connected to the Distribution Network without a meter recording its energy consumption Combined Neutral and Earth Voltages above 11kV. These may be both transmission and distribution networks depending on location and requirement Voltages above 1000V; generally used to describe 11kV or 6.6kV distribution systems but may include higher or other legacy voltages Independent Connection Provider LV Voltages up to 1000V; generally used to describe 230/400 Volt or 230/460 Volt distribution systems PME SNE SWA TN-C-S VIR Protective Multiple Earthing, refer to TNC-S Separate Neutral and Earth Steel Wire Armoured a cable type Terra Neutral-Combined-Separate. The approved method of providing a PME supply within UK Power Networks. Refer to EDS Vulcanised Rubber Cable a type of cable insulation UK Power Networks 2018 All rights reserved 6 of 18

7 4 Supplies Overview Type of Connection Service Length Service Cable Section New single supply <500W connection to LV main Maximum of 40m from the service joint for underground main connections, or the base of the pole for overhead main connections 25mm 2 single-phase aluminium concentric cable 5.2 Looped <500W connection from existing service Maximum total length of original and looped service shall not exceed 40m from the service joint for underground main connections, or the base of the pole for overhead main connections. Original cable shall be a minimum of: 16mm 2 aluminium or, 25mm 2 single-phase aluminium concentric cable mm 2 copper or, inch 2 copper New single supply >500W and <2kW connection to LV main As per new single supply <500W with no additional looped supplies on service allowed 25mm 2 single-phase aluminium concentric cable 5.4 New supply within inaccessible or dangerous area As per new single supply <500W, shall be terminated in approved mini pillar in safe location to supply private network 25mm 2 single-phase aluminium concentric cable 5.5 Existing service cable is 4mm 2 singlephase copper concentric cable or smaller 4mm 2 single-phase copper concentric cable Transfer of existing supply to new <500W asset Existing service cable is either: 16mm 2 aluminium or, 15mm 2 copper or, inch 2 copper or, 25mm 2 single-phase aluminium concentric cable mm 2 aluminium Total length of 20m from service joint. Relocation of existing <500W supplies. Existing service cable is either: 16mm 2 aluminium or, 15mm 2 copper or, inch 2 copper 25mm 2 single-phase aluminium concentric cable 6.3 Total length of 40m from service joint. Existing service cable is 25mm 2 single-phase aluminium concentric cable 25mm 2 single-phase aluminium concentric cable UK Power Networks 2018 All rights reserved 7 of 18

8 5 New Unmetered Supplies 5.1 Overview This section covers new unmetered supplies using service cables approved for use within the three UK Power Network license areas. 5.2 Standard Supply A single-phase asset not exceeding 500W that is to be supplied at LV and is unmetered shall be supplied via a 25mm 2 aluminium single-phase concentric service cable (refer to EAS ) which shall be terminated into 25A cut-out (refer to EAS ). The service cable shall be a maximum of 40 metres in length from either the underground LV service joint or the base of the supplying LV pole. The 25A cut-out shall be fused in accordance with the earth loop impedance at the cut-out location, refer to Section 7.1. If a maximum 40 metre service length cannot be achieved; the LV distribution network shall be extended with an appropriate LV mains cable (refer to EDS ) to a position that allows safe installation and access of both the LV distribution network and the asset (refer to Section 5.5). All new unmetered supplies shall be ground-mounted only; UK Power Network shall not provide or adopt new LV, HV or EHV overhead distribution network pole-mounted unmetered assets. All new supplies shall be single-phase only; new three-phase unmetered supplies shall not be provided. Unmetered supplies shall be separated by a minimum of 2 metres if the asset is a bonded bare metal, Class I or Class II enclosure. Assets with insulated installations are not constrained by this separation. Insulated installations may include: No conductive material in contact with the mass of earth nor, Bonding to a bare metal casing. Refer to EDS for information regarding earthing for unmetered supplies and the Class I and II enclosures. Service cables for an unmetered supply direct from an LV overhead distribution network shall be laid in an approved 32mm duct (refer to EAS ) from the ground entry point for a minimum of 1 metre from the LV distribution pole. Upon energisation, a certificate of energisation shall be completed, refer to Section UK Power Networks 2018 All rights reserved 8 of 18

9 5.3 Looped Supplies New unmetered supplies of <500W shall be taken directly from the LV distribution network or an extension of the LV distribution network in accordance with Section 5.2. Where this cannot be achieved for practical or safety concerns, a single additional looped supply of <500W may be taken from an existing unmetered asset supplied directly from the LV distribution network. Looped supplies from cut-outs shall be taken from approved 25A cut-outs and shall use the approved 25mm 2 aluminium service cable terminating in an approved 25A cut-out (refer to EAS ). The looped service shall be taken from the bottom exit point of the approved 25A cut-out; looped supplies shall not be taken from the customer exit point of the approved 25A cut-out. Alternatively looped supplies may be taken from a crutch joint off of the service cable to the existing unmetered asset. If the existing unmetered asset is supplied by an approved 25mm 2 aluminium, 16mm 2 aluminium, 15mm 2 copper or inch 2 copper service cable the total length of existing service and new looped service shall not exceed 40 metres. Looped supplies shall not be provided from any other service cable. A PME earth electrode shall be provided by the customer at the looped supply. The total loop demand including first and second supplies shall not exceed 2kW of maximum power requirement. 5.4 Supplies in Excess of 500W Assets with a load requirement between 500W and less than 2kW or modular assets with the capability to increase their load requirement above 500W but less than 2kW from an unmetered supply shall: Use a minimum service cable of 25mm 2 single-phase aluminium concentric cable as defined by EAS Existing service cables of a smaller cross section shall not be used and shall be replaced with the minimum approved 25mm 2 single-phase aluminium concentric cable. Have a maximum service length of 40 metres. Only be connected by a service directly connected to the LV distribution network main cable and shall not be loop connected, no loop shall be taken from nor shall be connected to a metered service. Use the approved cut-outs as specified in EAS Comply with EDS Refer to Section 7.1 for appropriate supply fuse selection. Should the customer wish to operate or maintain any unmetered supply equipment capable of exceeding 500W without direct reference to UK Power Networks, a switch fuse isolator (of a type in accordance with BS 7671) shall be installed immediately after the cut-out. UK Power Networks 2018 All rights reserved 9 of 18

10 5.5 Supplies at Inaccessible, Third Party Owned or Dangerous Locations UK Power Networks and ICPs shall not provide direct unmetered services to assets: On a roundabout (except for a turning circle within a cul-de-sac). In a public highway where no LV distribution network can be extended to within 40 metres of the asset. In the centre of a road including central reservations. Mounted on a wall. Sites that fall into these criteria shall be supplied at a single location by an LV mini pillar supplied by the customer or an ICP. Direct supplies to assets on third party owned land shall have all necessary land rights before construction commences (refer to Section 7.3). Where the necessary land rights for a direct supply cannot be granted, assets shall be supplied by an LV mini pillar supplied by the customer or an ICP. Supplies from LV mini pillars within the locations listed in this section shall be owned and maintained by the customer. UK Power Networks 2018 All rights reserved 10 of 18

11 6 Existing Supplies 6.1 Overview This section covers existing unmetered supplies using typical service cable examples previously approved for use within the three UK Power Network distribution network areas. 6.2 Transfer of Supplies Where an unmetered asset is to be replaced in the public highway at the same location, or at a new location within 2 metres of the existing asset still remaining within the public highway, the service to the existing equipment may be transferred to a new unmetered asset. A new section of service cable may then be jointed to the remnant of the original service cable. Refer to Section 6.3 for the relocation of services greater than 2 metres from the original position. The size of new section of service cable used will be dependent on the size of the existing service cable and the distance between old and new locations. Where the existing service has a cross section area of greater than 16mm 2 for aluminium cores or 0225in 2 /15mm 2 for copper cores, the new section of cable shall be 25mm 2 aluminium concentric cable. Where the existing cable has a 4mm 2 copper core, the new section of cable shall be 4mm 2 copper concentric cable. The existing service shall be in a satisfactory condition. Existing pole-mounted assets shall only be replaced on a like for like basis. The existing service cable feeding the existing pole-mounted asset shall be disconnected from the overhead line and removed completely. A 25mm 2 single-phase aluminium concentric cable, terminating in the approved 25A cut-out, shall be installed to supply the replacement polemounted asset. Note: Swinging lights, i.e. street lighting assets that are suspended across the highway by wire connections or are similarly not directly fixed to a rigid mount, shall not be replaced on a like for like basis and transfers using the existing service shall not be made. These services shall be removed at the first opportunity. Unmetered supplies mounted upon HV or EHV overhead distribution network poles shall not be replaced and an alternative solution shall be found. UK Power Networks 2018 All rights reserved 11 of 18

12 6.3 Relocation of Supplies Where an existing unmetered supply is to be replaced greater than 2 metres from the original location, the existing service cable type shall be identified and the existing service length from the service joint on the LV distribution network main cable to the existing location determined. If the existing service cable is of an approved type and can be jointed to a 4mm 2 copper concentric cable it shall be treated as a service transfer detailed in Section 6.2. If the existing service cable is any of the following the service may be relocated up to a total of 20 metres from the service joint using 25mm 2 aluminium concentric cable: 16mm 2 aluminium concentric. 15mm 2 copper concentric inch 2 copper concentric cable. Once extended to 20m this service may not be further extended to 40m. If the existing service cable is a 25mm 2 aluminium concentric cable as per section 6.2 and can be demonstrated to be a 25mm 2 service for the entire length from the service joint to the current asset location, the service may be relocated up to 40 metres from the service joint. Relocation distances greater than those specified above shall be provided by a new service (refer to Section 5) and the existing service cable disconnected (refer to Section 7.5). 6.4 Existing Looped Supplies Where a customer wishes to replace a number of loop supplied assets, the loop may be maintained by a direct connection to the LV distribution network if the following conditions can be satisfied: The unmetered supplies are to be replaced within 0.5m of the existing asset. The existing service cable to each asset is owned by UK Power Networks (refer to Section 6.7 for ownership criteria). The existing assets do not exceed 500W and the total maximum power requirement for the total loop does not exceed 2kW. Where the criteria above cannot be satisfied, the existing loop shall be supplied by an LV mini pillar. The appointed connection provider shall maintain all looped supplies. The maximum number of assets on an existing loop shall be constrained by the fuse size of the primary supply (refer to Section 7.1) and the voltage of each looped asset. The voltage of any looped asset shall not be lower than 216V for a single-phase supply or 376V for a threephase supply. If a single unmetered asset is to be removed from an existing loop owned by UK Power Networks, the continuity of the loop shall be maintained by either the straight jointing of the existing service cables once the single unmetered asset is removed or excavation of the disconnected existing service cables and replacement with a single service cable to replace the loop connection. UK Power Networks 2018 All rights reserved 12 of 18

13 6.5 Existing Unmetered Three-phase Supplies Previously, a number of 60A three-phase and neutral supplies have been provided within the UK Power Networks distribution network areas. Unmetered three-phase supplies shall be replaced on request on a like for like basis at the same location as the original asset. However, unmetered three-phase supplies shall not be relocated, transferred, increased or decreased in capacity. Furthermore, no new unmetered three-phase supplies shall be accepted within the UK Power Networks distribution network areas. 6.6 Existing Fifth Core and Switched Supplies There are a significant number of historic, dedicated lighting supply networks within the UK Power Networks distribution network areas. These may be fifth core networks, switch supply networks or other dedicated lighting networks directly supplied by a network distribution substation that were not designed or intended for the purpose of distributing domestic metered LV supplies. These should not be confused with existing looped supplies (refer to Section 6.4) Where existing dedicated lighting network supplied assets are to be replaced on an individual basis, these assets shall be removed from the existing fifth core network, supplied directly by the LV distribution network and connected directly to a phase core and not a smaller sized core in accordance with Section 5.2. Where looped assets are supplied by a dedicated lighting network, the loops shall be removed from the dedicated lighting network and supplied directly from the LV distribution network in accordance with Section 6.4. For guidance on the removal of LV distribution substations that supply dedicated lighting networks refer to EDS UK Power Networks 2018 All rights reserved 13 of 18

14 6.7 Historic Cables and Cut-outs with Operational Concerns This includes VIR insulated, lead sheathed, service cables, fused neutral cut-outs, lead pot terminations and general condition based concerns. VIR Insulated SWA service cables to unmetered assets are assumed to be under the ownership of the local authority (Borough or County Council) or an IDNO and are not owned by UK Power Networks unless ownership can be demonstrated. UK Power Networks ownership can be identified by either: A cable is demonstrated to be directly connected to the UK Power Networks LV distribution network, not looped supplied, supplied from a lighting pillar or similar indirect connection. Production of a valid adoption certificate by the local authority, showing that the cable has been adopted by UK Power Networks or the previous Distribution Network Operator. UK Power Networks shall provide assistance to a local authority to determine the source of supply for all historic cables. If adoption cannot be agreed, VIR insulated unmetered service cables shall be permanently disconnected in accordance with Section 7.5 and replaced in accordance with Section 4. If UK Power Networks ownership is demonstrated then VIR insulated cables may be worked upon live if the exposed insulation is found to be good condition with no visible breaks or cracks. If the insulation is found to be damaged, all works shall be conducted dead. All cut-outs with fused neutrals shall be replaced. Cut-outs found to be damaged or in poor condition shall be replaced and fused in accordance with the existing fuse. Lead pot type terminations in a serviceable condition will not be replaced unless other work is being carried out to the service cable or cut-out. UK Power Networks 2018 All rights reserved 14 of 18

15 7 General Requirements 7.1 Earthing All unmetered supplies shall be PME, supplied by a combined neutral earth cable. Separate neutral earth or split concentric cables shall not be used for unmetered supplies, refer to EDS All unmetered supplies shall be fused in accordance with Table 7-1 to ensure sufficient fuse clearance under fault conditions. Table Maximum Earth Fault Loop Impedance for fuse selection Fuse Rating (A) Maximum Earth Fault Loop Impedance () Earth loop impedance values outside this range shall not be accepted for unmetered supplies; additional work shall be required if an acceptable earth loop impedance cannot be achieved. If this is not feasible the unmetered supply shall be rejected at or removed from that location. 7.2 Intake Position The intake position for an approved cut-out shall, prior to a connection being undertaken, be: Electrically safe to allow for the termination of the approved cut-out. Provided with a BS 7671 electrical test certificate. Watertight and secured with the appropriate tool. If a cut-out cannot be installed or operated in a safe manner within an unmetered asset the customer shall be required to either: Replace the asset with a suitable asset capable of accepting an approved 25A cut-out. Install an alternate asset at an adjacent location to which a connection can be made. Install an LV mini pillar supplied by the customer or an ICP for the customer to install their own private network from the pillar to their asset. 7.3 Legal Requirements All necessary consents relating to the service cables and access arrangements shall be provided by the customer. If UK Power Networks equipment is to provide a strategic purpose additional to the function of a supply point for an unmetered supply customer, UK Power Networks shall ensure that its interests are adequately protected by the agreed tenancy arrangements. Necessary land rights shall be secured before starting construction as detailed in EDS UK Power Networks 2018 All rights reserved 15 of 18

16 7.4 Temporary Disconnection When a temporary removal of an unmetered supply is required for a maximum of 4 months, the service cable shall be cut and pot-ended before the cut-out. The pot-end shall be made secure and reburied at the location of the unmetered asset for use within 4 months. If the 4 month limit expires, UK Power Networks or the acting ICP shall immediately disconnect the service cable as per Section 7.5. De-energisation and energisation certificates shall be completed at each stage of the temporary process. Refer to Section Disconnection When disconnection of an unmetered supply is required the service cable should be traced back from the asset to the service joint. The service cable shall then be cut and pot ended towards the LV distribution network main cable as close as is practical to the service joint. Where safe and practicable, and subject to a risk assessment, the short length of service cable remaining live should be strapped to the LV distribution network main cable with cable ties. For any unmetered asset less than 3 metres from the supplying LV distribution network main cable; the unmetered service cable shall be fully exposed from the unmetered asset to the supplying LV distribution network main cable. For any unmetered asset greater than 3 metres from the supplying LV distribution network main cable, full exposure of the unmetered service cable shall only be considered if such work will not impact the public highway or if no other approved means of tracing the service cable is available. For any ground mounted unmetered asset supplied from an adjacent overhead LV distribution network, the descending cable shall be left intact and the service cable pot-ended within 1 metre of the supplying pole. For a pole-mounted asset the service cable feeding the asset shall be disconnected from the overhead line and removed completely. In all instances network records shall be updated to reflect the changes. In the event that the original service joint location cannot be located or it is impractical to expose the service joint (e.g. obstructed by other services or encased in concrete) the existing service should be cut and pot ended as near as possible to the LV distribution network main cable and the position of this pot end marked and identified on the operational network records. For all disconnected services that are to be abandoned, a continuity check shall be carried out on the disconnected cable to ensure that it is the correct cable. A further test shall be carried out to ensure that no other services have been affected by the disconnection. It is essential that the location of the pot ended service and any abandoned cable should be marked on the operational network records. On de-energisation, a certificate of de-energisation shall be completed, refer to Section UK Power Networks 2018 All rights reserved 16 of 18

17 7.6 Documentation Certificate to Confirm Unmetered Supply Energisation When any work to energise an unmetered supply is carried out, the appropriate notification of energised electricity apparatus certificate shall be completed in accordance with HSS Subject to agreement with the local customer, a copy of this document shall be returned to UK Power Networks or the acting ICP for forwarding to the customer upon request Certificate to Confirm Unmetered Supply De-Energisation When any work to de-energise an unmetered supply is carried out, the appropriate disconnection certificate shall be completed in accordance with HSS Subject to agreement with the customer, a copy of this document shall be retained by UK Power Networks or the acting ICP for forwarding to the customer upon request. UK Power Networks 2018 All rights reserved 17 of 18

18 8 References 8.1 UK Power Networks Standards EAS EAS EDS EDS EDS EDS EDS EDS EDS EDS HSS Approved Materials List Cables and Joints Approved Materials List LV Plant Materials List Customer Installation Earthing Design Pre-Design Requirements for Secondary Substations (internal only) Multi-Occupied Building Supplies LV Network Design LV Customer Supplies Above 100A Single-phase LV Customer Supplies up to 100A Single-phase HV Customer Demand and Generation Supplies EHV Customer Demand and Generation Supplies Energisation and Disconnection of Electrical Apparatus and Plant including all Cables 8.2 National and International Standards BS7671 BS (Amendment ) IET Wiring Regulations 9 Dependent Documents The documents below are dependent on the content of this document and may be affected by any changes. EDS EDS EDS EBP EDS EDS EDS EDS EDS Earth Fault Loop Impedance Requirements LV Network Earthing Design Customer Installation Earthing Design Pilot for Unmetered Live Connections to Overhead Lines Multi-Occupied Building Supplies LV Network Design LV Customer Supplies Above 100A Single-phase LV Customer Supplies up to 100A Single-phase Appendices to ENA ER G81 UK Power Networks 2018 All rights reserved 18 of 18