Document Number: EDS 07-1119 Version: 1.0 Date: 24/05/2017 THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE ENGINEERING DESIGN STANDARD EDS 07-1119 SUBSTATION ELECTRICAL SERVICES Network(s): EPN, LPN, SPN Summary: This standard specifies the electrical services requirements including lighting, socket outlets and power circuits for other electrical equipment for substations at all voltages. Author: Stephen Tucker Date: 24/05/2017 Approver: Barry Hatton Date: 09/06/2017 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. Applicable To 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
Transcript
Document Number: EDS 07-1119
Version: 1.0
Date: 24/05/2017
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ENGINEERING DESIGN STANDARD
EDS 07-1119
SUBSTATION ELECTRICAL SERVICES
Network(s): EPN, LPN, SPN
Summary: This standard specifies the electrical services requirements including lighting, socket outlets and power circuits for other electrical equipment for substations at all voltages.
Author: Stephen Tucker Date: 24/05/2017
Approver: Barry Hatton Date: 09/06/2017
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.
New standard to cover the electrical services requirements in all substations. The electrical services requirements from EDS 07-0102, EDS 07-0105 and EDS 07-0020 have included. The testing and recording requirements from EDS 07-0027 (now withdrawn) have also been included in this document.
This standard specifies the electrical services requirements including lighting, socket outlets and power circuits for substations at all voltages.
Typical equipment layouts and associated drawing notes are included in Appendix A; however this document should be read in conjunction with the following civil design standards which include further details:
EDS 07-3102 – secondary substations.
EDS 07-0105 – grid and primary substations.
EDS 07-0020 – customer supplies and generation connections.
2 Scope
This standard applies to the installation, repair, replacement, extension and testing of internal electrical services in all grid, primary and secondary substations and includes:
Installation from the point of supply i.e. cut-out.
Lighting and power circuits.
Other equipment e.g. heating, dehumidifiers etc.
Other power circuits e.g. battery chargers, fans, pumps etc.
Testing and records.
The installation of the LV supply is excluded. Refer to EDS 08-1112 for the approved options.
3 Glossary and Abbreviations
Term Definition
Consumer Unit1 A particular type of distribution board comprising a type-tested co-ordinated assembly for the control and distribution of electrical energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming circuit(s) and an assembly of one or more fuses, circuit-breakers, residual current operated devices or signalling and other devices proven during the type-test of the assembly as suitable for such use.
Disconnector1 A mechanical switching device which, in the open position, complies with the requirements specified for the isolating function. A disconnector is otherwise known as an isolator.
Distribution Board1 An assembly containing switching or protective devices (e.g. fuses, circuit-breakers, residual current operated devices) associated with one or more outgoing circuits fed from one or more incoming circuits, together with terminals for the neutral and circuit protective conductors. It may also include signalling and other control devices. Means of isolation may be included in the board or may be provided separately
Grid/Primary Substation Any substation 132kV, 66kV or 33kV
Hazardous Area Zone 1 An area in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas or vapour is likely to occur in normal operation occasionally (BS EN 60079-10-1)
Secondary Substation Any substation operating at 20kV, 11kV or 6.6kV
SWA Steel Wire Armoured cable
UK Power Networks UK Power Networks (Operations) Ltd consists of three electricity distribution networks:
Eastern Power Networks plc (EPN).
London Power Network plc (LPN).
South Eastern Power Networks plc (SPN).
4 General Requirements
All new and replacement electrical services shall be designed and constructed in accordance with BS 7671 including the latest amendments.
All electrical services shall be designed and constructed having due regard for the requirements of the CDM Regulations.
All equipment shall be located to enable easy dismantling of switchgear after erection for maintenance purposes.
Switchgear shall be positioned to allow adequate and safe operating space in front and where necessary at the rear.
Only approved equipment and fittings shall be used within a UK Power Networks substation.
All grid and primary substations shall use minimum IP20 rated (to BS EN 60529) corrosion resistant, metalclad, surface mounted accessories.
All secondary and GRP substations shall use IP56 rated (to BS EN 60529) surface mounted accessories from the MK Masterseal range or equivalent. Where specific accessories are not available (e.g. fuse connection unit) they can be assembled using the modular grid accessories and suitable enclosures.
All surface mounted accessories and outlets shall be mounted on boxes from the same manufacturer and range as the accessory or outlet.
All accessories with more than two switches shall be grid pattern with cover plates to match the power accessories.
Metal boxes shall be of the type without knockouts. Conduit entries shall be cut on site.
Battery rooms with vented batteries shall use intrinsically safe light fittings and accessories suitable for a zone 1 hazardous area. Further information on hazardous area classification and the selection and use of appropriate electrical equipment can be found in BS EN 60079-10-1 and BS EN 60079-14.
The provision of an LV supplies to substations at all voltages is detailed in EDS 08-1112. The LV supply shall be terminated in an appropriate cut-out as detailed in EDS 08-1112.
6 LVAC Panel
All new grid and primary substations shall include a purpose built cubicle type LVAC board located in the auxiliary room. The LVAC board shall contain a distribution board with integral disconnector (Section 7), fuse switches and control devices etc. and shall supply all the low voltage equipment associated with the building services installation throughout the substation.
The LVAC panel shall be sized to suit the substation; a full LVAC panel is unlikely to be required at small primary substations and 33kV switching sites where a distribution board would be suffice.
The LVAC panel shall be constructed of cast metal and/or sheet steel (not less than 1.25mm thick).
The external loop impedance of supply at the LVAC panel is assumed will be no greater than 0.35 ohms for design purposes.
The LVAC panel shall be bonded to earth in accordance with ECS 06-0022.
A minimum clearance of 1000mm shall be maintained in front of the LVAC panel.
A typical LVAC panel layout is shown in Appendix A. Refer to EDS 07-0105 for further details.
7 Distribution Board
7.1 General
All distribution boards shall be rated at 500V and comply with BS EN 61439-3; substation specific requirements are detailed in Section 7.2 (secondary) and Section 7.3 (grid and primary).
All distribution boards shall include:
A 100A/125A double-pole (phase and neutral) or 125A 4-pole (three-phase and neutral) disconnector with 15kA breaking capacity to BS EN 60947.
Relevant RCBOs to BS EN 61009-1 or MCBs to BS EN 60898-2 with a minimum 15kA breaking capacity as follows:
16A/20A RCBO Type B for each circuit supplying 13A socket outlets.
32A MCB for each test equipment 3-phase and earth socket outlet.
16A MCB for each test equipment 13A socket outlet.
20A RCBO Type C for each item of fixed equipment.
6A/10A MCB for each lighting circuit.
6A MCB for each RTU or PLTU.
A separate MCB for each battery charger.
A separate MCB for all other circuits e.g. fans, pumps, intruder alarm etc.
RCBO/MCBs selected as appropriate based on the load characteristics. Type B shall be used for socket outlets for portable equipment and Type C shall be used for fixed equipment (e.g. pumps, fans, battery charger etc.).
25% spare ways for future requirements complete with blanking plates.
Provision shall be allowed for padlocking off individual RCBOs/MCBs.
All distribution boards shall be arranged for conduit entry.
7.2 Secondary Substations
All secondary substations shall use a phase and neutral insulated distribution board (consumer unit) rated at 500V to BS EN 61439-3.
The distribution board shall be installed within 3 metres of the cut-out and mounted at a height of 1350mm to 1450mm above finished floor level2.
If the secondary substation requires a three-phase supply for a test equipment socket (e.g. secondary substation with multi-panel switchgear) the distribution board shall comply with Section 7.3.
7.3 Grid and Primary Substations
All grid and primary substations shall use a three-phase and neutral metalclad heavy gauge steel distribution board(s) rated at 500V to BS EN 61439-3. The number and size of distribution boards shall be suitable for the size of the site.
The distribution board should be installed within 3 metres of the cut-out at a suitable height and location to allow operation from ground level. The distribution board shall also be positioned to allow adequate space for termination of the incoming and outgoing cables, etc.
Note: If distance between the distribution board and cut-out is greater than 3 metres an additional isolator is required to comply with BS 7671.
2 Based on Building Regulations Approved Document P.
Consideration shall be given to the accessibility of all lighting fittings for lamp changing and maintenance both inside and outside the buildings.
All luminance (Lux) levels are based on the guidance in HSE HSG38.
8.2 Internal Lighting
8.2.1 General
General purpose light fittings shall be of the fluorescent impact resistant type with a polycarbonate prismatic diffuser to BS EN 60598-1. The preferred size is 1500mm twin fitting.
Light fittings shall be fitted 35W or 49W T5 or T16 linear fluorescent tubes of the high frequency energy efficient type to BS EN 60081 (or equivalent LED).
All lamps shall have caps of the ‘bi’ pin type and shall have a minimum colour temperature of 3500K (a white appearance).
Light fittings shall have a minimum degree of protection of IP42 (to BS EN 60529). All secondary substations and other substations susceptible to water ingress (e.g. underground, vault, basement etc.), shall use IP56 (to BS EN 60529) rated light switches and corrosion resistant light fittings to BS EN 60598-1.
Light fittings should be connected via a plug in rose or similar arrangement with the same degree of protection (to BS EN 60529) as the light fitting to aid future maintenance. A protective conductor shall be connected to the earth terminal of each fitting.
A surface mounted light switch with back box to BS EN 60669-1 shall be positioned adjacent to the substation or room access. Substation or rooms with two or more points of access shall have a light switch adjacent to each room access wired using a 2-way lighting configuration.
Surface mounted light switches shall contain neon indicators to assist in their location.
All light switches shall be mounted at 1400mm above finished floor level.
8.2.2 Secondary Substations
Secondary substations shall have a minimum luminance of 300 Lux. This can generally be achieved with one light fitting per 10m2
. If required additional light fittings shall be installed to provide adequate luminance to all areas. The light fittings shall be positioned to avoid shadows when equipment doors are open.
A GRP substation shall have a minimum of one light fitting above the door.
A brick-built substations shall have a minimum of two light fittings on opposite sides of the substation.
All light fittings shall be mounted at a maximum height of 2200mm above finished floor level and be positioned to aid future maintenance. Light fittings shall not be installed above an LV board.
Switchrooms shall have a minimum luminance of 300 Lux with a uniform light loss factor of 0.8 across the front and rear elevation of all the switchgear, including spare bays.
The light fittings shall be installed around the perimeter of the switchroom with equidistant spacing and at a height of 2250mm from finished floor level to the centre line of the fitting. Additionally light fittings may be suspended from the ceiling where required to achieve the specified luminance and uniform factor levels.
8.2.4 Auxiliary Rooms
Auxiliary rooms shall have a minimum luminance of 300 Lux with a uniform light loss factor of 0.8 across any island panel suites and wall mounted equipment.
The light fittings shall be installed on the ceiling with equidistant spacing.
8.2.5 Cable Basement
Cable basements shall have a minimum luminance of 100 Lux with a uniform light loss factor of 0.7 across the entire floor area.
The light fittings shall be installed on the ceiling with equidistant spacing.
8.3 Emergency Lighting
Emergency lighting shall comply with BS EN 1838 and BS 5266.
All brick-built substations shall include a minimum of one emergency light. An additional emergency light shall be installed where there is an open LV board.
Emergency lights shall have a minimum luminance of 1 Lux and shall be the integral, self-contained type to BS EN 60598-2-22 incorporating a fluorescent lamp (or equivalent LED) and a polycarbonate diffuser. The rated duration of emergency lights shall be 3 hours.
Emergency lighting may be tested by turning off the appropriate RCBO/MCB therefore dedicated test points are not required but may be installed if deemed necessary by the project manager.
Above door emergency lights shall include an exit legend plate.
8.4 External Lighting
8.4.1 General
All building exit doors (including basement door) shall have a light fitting above the external landing, mounted just above the transom level of the door.
All light fittings mounted on the external walls of a building shall be wired from inside of the building using the same wiring method as internal lighting.
External light fittings shall be IP65 (to BS EN 60529) heavy duty 26W TC-T (or equivalent LED) bulkhead type constructed in polycarbonate with an impact resistant polycarbonate cover, sealed to the body with a silicon rubber gasket and stainless steel captive fixing screws.
All wiring to be installed in conduit in accordance with Section 13 and 14.
All external lighting shall generally be controlled by photoelectric control units (complying with BS 5972) and PIR movement detectors.
8.4.2 Secondary Substations
External lighting is not required at secondary substations.
8.4.3 Compounds
External compounds shall have floodlights to provide a minimum luminance of 100 Lux.
Transformer bays shall have floodlights to provide a minimum luminance of 300 Lux and a ground illumination level of 50 Lux with a uniform light loss factor of 0.5 across the compound. Where transformers are enclosed the floodlights should be installed on surrounding building structures providing there is a clearance of at least 3.5m from all live parts of the adjacent transformer.
Floodlighting fittings shall have a minimum degree of protection of IP65 (to BS EN 60529) and shall be secured to an existing structure wherever practical or mounted on 5m lighting galvanised steel raise and lower columns. Floodlights shall be fitted with 500W metal halide lamps or equivalent LED. Floodlighting fittings shall be complete with high purity anodised aluminium reflectors, galvanised steel mounting brackets and shall be vandal resistant.
All covers shall be made of impact resistant polycarbonate and sealed to the body with a silicon rubber gasket and stainless steel captive fixing screws.
SWA cable shall be used throughout and routed through the cable ducts supplied from LVAC panel.
All floodlights shall be supplied via a designated ‘floodlight’ contactor in the LVAC panel and a 1-gang 1-way switch.
Radial circuits shall be used for all power circuits.
All socket outlets and fused connection units shall be surface mounted double-pole switched and shall comply with BS 1363.
If a substation is susceptible to water ingress (underground, vault, basement, etc.) all fittings shall be IP56 rated (to BS EN 60529) and conform to BS 1363. In external areas or in areas subject to dust or splashing water accessories shall be IP65 rated (to BS EN 60529).
All small power accessories should be mounted at 1000mm above finished floor level.
9.2 Socket Outlets
9.2.1 Secondary Substations
A double 13A socket outlet shall be installed in a GRP substation in addition any socket provided in the LV cabinet.
A minimum of two double 13A socket outlets shall be installed in a brick-built substation on opposite sides of the substation.
Secondary substations with ring main unit switchgear shall include an additional single 13A socket outlet designated and labelled as a ‘Test Equipment Socket’ and supplied via a separate MCB (refer to Section 7).
Secondary substations with multi-panel switchgear shall include a 32A 3-phase and earth socket outlet (to BS EN 60309-1) for test equipment and supplied via a separate MCB (refer to Section 7).
9.2.2 Switchrooms
Double 13A socket outlets shall be positioned every 6 metres around the perimeter of the switchroom.
A 32A 3-phase and earth socket outlet (to BS EN 60309-1) for test equipment shall be installed in the switchroom. The location shall be agreed with the project manager.
9.2.3 Auxiliary Rooms
Double 13A socket outlets shall be positioned every 6 metres around the perimeter of the auxiliary room.
A 32A 3-phase and earth socket outlet (to BS EN 60309-1) for test equipment shall be installed in the auxiliary room. The location shall be agreed with the project manager.
Battery chargers, sump pumps etc shall be supplied via a 20A lockable rotary disconnector.
All other low voltage fixed equipment (e.g. RTU, PLTU, heaters, dehumidifiers, water heater, warm air hand dryer etc.) shall be supplied via a fused connection unit. The fused connection unit shall be installed adjacent to the equipment and supplied from the power circuit or wired directly to the distribution board and allocated a separate circuit and MCB. Fused connection unit requirements are detailed in Table 9-1.
Any wall mounted extract fan shall be supplied via the local light circuit and switched by an integral PIR.
Heaters or dehumidifiers shall not be installed in secondary substations designed in accordance with EDS 07-3102.
Heaters and dehumidifiers shall be installed in other substations as detailed in Sections 10.2 and 10.3.
10.2 Heaters
All heaters shall comply with BS EN 60335-2-30 and BS EN 442.
Where required, convector or heavy duty finned tubular heaters with wire guards (where space is an issue) shall be installed with the capability of maintaining an internal temperature of 21ºC.
Heaters shall be controlled via a thermostat set at 15ºC and locked off against tampering. An override switch with a four-hour timer shall be installed to allow the ambient temperature to be increased to 21°C during occupation. The thermostat shall be mounted at 1400mm above finished floor level.
Heaters or a bank of heaters shall be supplied via a fused connection unit.
Heaters shall be mounted at approximately 400mm above finished floor level. The final position of all heaters shall be agreed with the project manager.
10.3 Dehumidifiers
Where required dehumidifiers shall be installed to maintain the relative humidity in the switchroom below 60% (measured in accordance with BS 1339-3).
Dehumidifiers shall only be controlled by a local humidistat. The humidistat shall be mounted at 1400mm above finished floor level.
Dehumidifiers shall be supplied via a fused connection unit.
Dehumidifiers shall be mounted at the height specified in the manufacturer’s installation instructions.
Each dehumidifier shall include a drain pipe routed directly through the wall into the rainwater gulley and each drain shall be installed complete with trace heating cable, which shall be installed in accordance with the manufacturer’s instructions. All condensate drains shall be neatly clipped to the wall and exit the building at a height which enables the end of the drain to be neatly fixed to the outside wall with a minimum protrusion.
Each dehumidifier shall include a set of humidity alarm contacts which shall be wired using 2 x 1.5mm2 single cores within separate conduit/trunking from each unit to an adaptable box at the mains position.
The intruder alarm system shall be supplied, installed, testing and commissioned by a specialist UK Power Networks approved contractor utilising equipment approved for use and compatible with current security standards.
Refer to UK Power Networks Company Security for further details.
12 Cabling
All cables shall be 6491B LS0H to BS EN 50525-3-41 and shall comply with BASEC. All insulation shall use phase or neutral colours in accordance with BS 7671 throughout the length of the conductor. Note: The use of coloured sleeves to mark conductors is not acceptable.
Multicore flexible LS0H cables to BS EN 50525-3-21 may be used for flex outlet wiring accessories, providing that the voltage is a nominal 230V or below. Flexible cables and cords shall be shall be finished in white unless otherwise specified.
Steel wired armoured LS0H cables to BS 6724 shall be used in external situations and other areas where the environment is considered unsuitable for conduit/trunking enclosed cables and shall be:
Secured adequately using proprietary clips and non-ferrous screws.
Installed with galvanised steel guards where mechanical damage is likely.
Installed with moisture-poof connection to fittings using sealed glands and PVC shrouds.
All cables shall use stranded copper conductors with the following minimum cross sectional area:
Cut-out tails 25mm2 (the cut-out should be suitably fused to the distribution board rating).
All cables, except external armoured cables and distribution board/consumer unit tails, shall be enclosed in conduit or trunking. The types and sizes shall be suitable for the operating conditions.
All cables shall be installed without joints other than at equipment and terminal fittings.
Cables of differing voltages and of varying electrical services shall be segregated from each other by a minimum of 150mm unless stated otherwise in BS 7671 and other relevant standards applicable to the services involved.
Cables shall be installed and fixed to manufacturers’ recommendations and in accordance with BS 7671.
Sufficient slack shall be left at all cable terminations to permit two future stripping and reconnections without causing undue stress in the cable.
All final connections shall allow sufficient length of cable for equipment removal and maintenance.
13.2 Underground Cables
All underground cable routes shall be agreed before the work commences.
Unless otherwise stated, all underground cables shall be LS0H sheathed and steel wire armoured (see Section 12).
All underground cables shall be installed in accordance with ECS 02-0019.
All auxiliary cables shall be installed in ducts or troughs where practicable to afford maximum mechanical protection.
Steel and PVC conduit shall comply with BS EN 61386-1. All conduit shall be sized in accordance with the latest edition of BS 7671 with a minimum size of 20mm diameter.
Plastic conduit (in accordance with Section 14.1.2) shall be used in all general applications. Steel conduit (in accordance with Section 14.1.3) shall only be used in areas of impact high potential.
There shall be sufficient junction boxes, draw-in boxes and inspection fittings installed to allow cables to be inspected, withdrawn and replaced if necessary. Purpose made bends may be used providing the cable bending radius is maintained. All adaptable boxes and accessories shall have the same finish as the conduit and shall be fitted with earthing terminals. The adaptable boxes and accessories shall be of the raised back type to maintain an even spacing behind the conduit when used with distance saddles.
Joints between conduits may be push-fit, compression, mechanical locking or socket-end sealed with PVC adhesive. Where a weatherproof or watertight connection is required push-fit arrangement alone is not acceptable.
Distance saddles shall be used to fix surface-mounted conduit to provide a minimum clearance of 6mm. Saddles shall be placed at intervals of no more than 1200mm for steel or 750mm for plastic and not more than 200mm from any bend, joint or accessory. The finish shall match the conduit.
The conduit shall be installed in horizontal and vertical runs. Where several conduits follow similar routes they shall be grouped into neat, closely spaced runs.
Adaptable boxes shall be used to collect conduits from multi-directional runs or wherever the appearance of the conduit system may be improved by their use, e.g. where multiple runs change direction through 90 degrees.
The complete installation shall be arranged using a loop-in type system with joints being carried out at switches, isolators or appliance fittings.
All boxes and accessories shall be secured independently.
14.1.2 Plastic Conduit
All conduit, boxes and fittings shall be high impact, non-flame propagating, self-extinguishing, heavy-duty PVC conduit to BS EN 61386-1. Dimensions shall comply with BS EN 60423.
All conduit boxes and fittings shall comply with BS EN 61386-1 and the finish shall match the conduit.
All steel conduit shall comprise heavy grade, welded seam conduit and be provided with screwed ends. Dimensions shall comply with BS EN 60423. The conduit shall be a class 4 galvanised finish.
Conduit and adaptable boxes shall be constructed of malleable iron with threaded entries or bush entry looping boxes in accordance with BS EN 61386-1 and the finish shall match the conduit. Adaptable boxes shall be a minimum size of 100 x 100 x 50mm.
All accessories and fittings shall comply with BS EN 61386-1. The finish is to match the conduit.
The conduit system shall be completely installed and swabbed-through before any wiring commences. Cables shall not be pulled around any box, burr or other source of abrasion.
Bends shall be made using a bending machine.
The steel conduit installation shall be electrically and mechanically continuous throughout.
Running couplers shall only be used where no other form of coupling is accessible; their use shall be kept to an absolute minimum. Couplers shall be locked in position with milled edge locking rings.
File, ream and terminate all conduit ends in either:
Threaded spout entries.
Clearance holes in adaptable boxes, switch boxes and the enclosures of electrical equipment by means of a flange coupling, brass compression washers and a brass smooth bore male bush.
Clearance holes in adaptable boxes, switch boxes and the enclosures of electrical equipment by means of a coupler, shake proof washer and brass smooth bore bush.
14.2 Trunking
Surface steel and PVC trunking shall comply with BS EN 50085-1 and BS EN 50085-2-1. The finish of steel trunking shall be painted or galvanised as required. Trunking shall have a removable cover throughout its length with centre turnbuckle type latch fixings. Trunking bends shall be gusseted and of factory manufacture unless otherwise agreed.
Trunking shall be sized to comply with the requirements of BS 7671 with 25% spare capacity.
Cable trunking shall be installed either vertically or horizontally using manufacturer’s standard bends, elbows and tees with expansion joints fitted at all structural expansion points (where applicable).
Trunking shall be supported at intervals of no more than 2 metres horizontally or 2.5 metres vertically.
Where any trunking passes through a fire wall, the integrity of the fire compartment shall be maintained using suitable fire barriers both inside and outside the trunking.
Where the cable trunking passes through the building structure (e.g. walls or ceilings) the cover plate shall be fixed to the trunking before installation and be arranged to project 150mm each side of the hole.
Holes in trunking shall be made only by hole saw or other approved method.
Conductors of differing voltages may be installed in a common trunking, providing full compliance with the segregation requirements of BS 7671 are maintained throughout.
14.3 Cable Trays
Cable trays shall comply with BS EN 61537.
15 Earthing and Bonding
All equipment shall be bonded to earth in accordance with the relevant UK Power Networks earthing construction standard ECS 06-0022 (primary and grid substations) or ECS 06-0023 (secondary substations) or BS 7671.
No earth terminal shall be provided from the incoming service (i.e. TT earthing); all earthing and bonding shall use the substation earthing system.
The resistance of all protective conductors shall comply with BS 7671.
Earth terminals shall be provided at all light points, switch positions, sockets and fused connection units.
A protective conductor shall be connected between the earth terminal of each accessory and the earth terminal in the conduit box. All earth wires within boxes shall be sheathed with green/yellow PVC sleeving.
16 Labelling
All labelling shall comply with BS 7671.
All items of isolation and distribution equipment shall be labelled for ease of identification by means of the specified and/or detailed engraved labels.
All distribution board ways shall be permanently labelled to identify circuit function, cable size and protective device rating.
All switch/fuse isolators, busbar chambers and distribution boards containing 400V shall be clearly labelled ‘DANGER 400 VOLTS’, in red letters.
All 230V socket outlets without RCD protection shall be labelled ‘This socket outlet is not suitable for outdoor equipment’.
17 Hot Sites
All LV supplies to primary and grid HOT sites shall be provided in accordance with EDS 08-2108.
All sockets shall be disconnected or removed from any secondary substation designated as a HOT site. All lighting and RTU supplies from auxiliary terminals shall be via an isolation transformer.
Refer to ECS 06-0022 and ECS 06-0023 for further information on HOT sites.
Any defective wiring and equipment shall be replaced using the specification in this standard.
The whole installation shall be replaced where:
It is more cost effective,
It is not to the latest acceptable standards,
The luminance is insufficient for the area serviced.
If the existing distribution board/consumer unit is fed via a sub-main originating from an LVAC board, the cable shall be tested to ascertain if it can be retained and utilised as the main supply cable. If the cable is found to be defective it shall be replaced in accordance with Section 12.
Where a tariff meter has been installed, provision should be made for the metering to be refitted.
19 Testing, Certification and Records
All work shall be conducted and installed in accordance with BS 7671.
On completion of any works, the installation shall be tested in accordance with BS 7671 and an electrical installation certificate produced together with a schedule of test results as detailed in BS 7671.
The electrical system shall be recorded in the asset register and be setup with a routine test and inspection in accordance with EMS 10-0002 and EMS 10-6501.
The certificate and results using the relevant filename3 convention shall be sent to UK Power Networks for uploading into the asset register as follows:
1. UK Power Networks’ field staff – send a copy to the UK Power Networks Asset Registration Team (ART) via the appropriate mailbox below.
2. ICP – send a copy to UK Power Networks’ Competition-in-Connections Delivery Project Manager as part of the adoption acceptance processes.
3 The file name should contain the 7-digit site number (EPN: PowerOn number staring with a 3; LPN: 20 and 5-digit site number; SPN: 1 and 6-digit SPENS) followed by either ‘_eic’ or ‘_eic_results’ e.g. 1008488 _eic.pdf and 1008488 _eic_results.pdf for South Hove in SPN.
EDS 07-0020 Civil Requirements for New Customer Supplies and Generation Connections
EDS 07-0105 Grid and Primary Substation Civil Design Standards
EDS 08-1112 LVAC Supplies (future issue)
EDS 08-0121 Supplies to HOT Sites and National Grid Sites
EMS 10-0002 Inspection and Maintenance Frequency Schedule
EMS 10-6501 Inspection and Maintenance of Civil Assets
20.2 National Standards
Construction (Design and Management) Regulations 2015
BS 1339-3:2004 Humidity. Guide to the measurement of humidity
BS 1363-2:2016 13 A plugs, socket-outlets, adaptors and connection units. Specification for 13 A switched and unswitched socket-outlets
BS 1363-4:2016 13 A plugs, socket-outlets, adaptors and connection units. Specification for 13 A fused connection units switched and unswitched
BS 5266-1:2016 Emergency lighting. Code of practice for the emergency lighting of premises
BS 5467:2016
Electric cables. Thermosetting insulated, armoured cables of rated voltages of 600/1000V and 1900/3300V for fixed installations. Specification
BS 5972:1980 Specification for photoelectric control units for road lighting
BS 6724 Electric cables – Thermosetting insulated, armoured cables of rated voltages of 600/1 000 V and 1 900/3 300 V for fixed installations, having low emission of smoke and corrosive gases when affected by fire – Specification
BS 7211:2012 Electric cables. Thermosetting insulated and thermoplastic sheathed cables for voltages up to and including 450/750V for electric power and lighting and having low emission of smoke and corrosive gases when affected by fire.
BS EN 50085-2-1:2006+A1:2011 Cable trunking systems and cable ducting systems for electrical installations. Cable trunking systems and cable ducting systems intended for mounting on walls and ceilings
BS EN 50525-3-21:2011 Electric cables. Low voltage energy cables of rated voltages up to and including 450/750 V (U0/U). Cables with special fire performance. Flexible cables with halogen-free crosslinked insulation, and low emission of smoke
BS EN 50525-3-41:2011 Electric cables – Low voltage energy cables of rated voltages up to and including 450/750 V(U0/U) – Part 3-41: Cables with special fire performance – Single core non-sheathed cables with halogen-free crosslinked insulation, and low emission of smoke
BS EN 60079-10-1:2015 Explosive atmospheres. Classification of areas. Explosive gas atmospheres
BS EN 60079-14:2014 Explosive atmospheres. Electrical installations design, selection and erection
BS EN 60081:1998+A5:2013 Double-capped fluorescent lamps. Performance specifications.
BS EN 60309-1:1999+A2:2012 Plugs, socket outlets and couplers for industrial purposes. General requirements
BS EN 60423:2007 Conduit systems for cable management. Outside diameters of conduits for electrical installations and threads for conduits and fittings.
BS EN 60529:1992+A2:2013 Degrees of protection provided by enclosures (IP code).
BS EN 60598-1:2015 Luminaires. General requirements and tests
BS EN 60598-2-22:2014 Luminaires. Particular requirements. Luminaires for emergency lighting
BS EN 60335-2-30:2009+A11:2012
Household and similar electrical appliances. Safety. Particular requirements for room heaters
BS EN 60669-1:1999+A2:2008 Switches for household and similar fixed-electrical installations. General requirements
BS EN 60898-2:2006
Electrical accessories. Circuit-breakers for overcurrent protection for household and similar installations. Circuit-breakers for a.c and d.c. operation
BS EN 60947-1:2007+A2:2014 Specification for low-voltage switchgear and controlgear. General rules
BS EN 61009-1:2012+A12:2016 Residual current operated circuit-breakers with integral overcurrent protection for household and similar uses (RCBOs). General rules
BS EN 61386-1:2008 Conduit systems for cable management. General requirements
BS EN 61439-3:2012 Low-voltage switchgear and controlgear assemblies. Distribution boards intended to be operated by ordinary persons (DBO)
BS EN 61537:2007 Cable management. Cable tray systems and cable ladder systems
IEC 61950 Cable management systems - Specifications for conduit fittings and accessories for cable installations for extra heavy duty electrical steel conduit
Typical lighting and power layouts for GRP and brick-built secondary substations are shown in Figure A-1 and Figure A-2 respectively. Refer to EDS 07-3102 for further details.
Figure A-1 – GRP Secondary Substation Typical Lighting and Power Layout
Figure A-2 – Brick-built Secondary Substation Typical Lighting and Power Layout
Typical lighting and power layouts for brick-built 33kV customer connection substations are shown in Figure A-3. Refer to EDS 07-0020 for further details.
Figure A-3 – Brick-built 33kV Customer Connection Substation Typical Lighting and Power Layout
