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Document Ref: EI 07-0105 Civil COP Rev D 1

EDS 07-0105 Grid & Primary Substation Design Guide

Mark Dunk Revision D

Engineering Standards

Grid & Primary Substation Design Guide Revision D

Document Ref: EDS 07-0105 Civil Design Guide Rev D 2

Originated by: Name M R Balaie

Role Civil Design Manager

Signature M R Balaie

Date 20/11/2006

Revised to Revision D Name Mark Dunk

Role Civil Standards Manager

Signature

Date




CONTENTS Page No. 1.0 INTRODUCTION 6 2.0 DESIGN CONSIDERATIONS 7 2.1 Functional Requirements 7 2.2 Life Span 7 2.3 Future Maintenance 7 2.4 Legislation 7 2.5 Environment 8 2.6 Operational 9 2.7 Health and Safety 9 2.8 Electrical Apparatus 9 2.9 Cable Entries 9 2.10 Security 9 2.11 Flooding 10 2.12 Fire Risk Assessment 11 3.0 STANDARDIZATION AND GENERIC CIVIL DESIGN 12 4.0 SITE LAYOUTS AND BUILDING CONFIGURATION 13

5.0 GENERAL LAYOUTS & REQUIREMENTS OF BUILDINGS, SWITCH HOUSES, CONTROL ROOMS & RELAY ROOMS 14

5.1 General 14 5.2 Switch Houses – General 14 5.3 Switchroom 15 5.4 Cable Trench & Switchgear Support 15 5.5 Cable Basement 16 5.6 Auxiliary Room 17 5.7 L.V.A.C. & Telecom Room 17 5.8 Battery Room 18 5.9 Washroom / Toilet 19 5.10 Store Room 20 5.11 Mess Room 20 6.0 SWITCH HOUSE ELEMENTS AND MATERIALS 21 6.1 General 21 6.2 Foundations 21 6.3 Walls 21




6.4 Roofs 23 6.5 Finishes 23 6.6 Doors 24 6.7 Internal and External Stairs 25 6.8 Thermal Insulation 25 6.9 Building Services 25

7.0 TRANSFORMER BAYS 26 7.1 General 26 7.2 Noise and Acoustic Housings 27 7.3 Segregation of Transformers 29 7.4 Oil Containment of Transformers 29 8.0 ALUMINIUM AND STEEL SUPPORT STRUCTURES & FOUNDATIONS 32 8.1 Structure Design 32 8.2 Serviceability 32 8.3 Finishes 32 8.4 Foundation Design 32 9.0 EXTERNAL WORKS 34 9.1 Site 34 9.2 Roadways / Pedestrian Access 34 9.3 Fencing 35 9.4 Drainage 38 9.5 Transformer Delivery 39 9.6 Switchgear Delivery 40 9.7 Combined Services 40 9.8 Ground Finishes 40 10.0 EXISTING SITES 41 11.0 EARTHING 41 12.0 FURNITURE 42 13.0 HEALTH AND SAFETY AND ENVIRONMENT 42 14.0 REFERENCE DOCUMENTS 45

APPENDIX A – BUILDING SERVICES SPECIFICATION

48




1.0 INTRODUCTION

This document outlines the principal requirements to be incorporated within a civil design of a 33kV/11kV Primary Substation, a 132/33kV Grid Substation, a direct transformation 132/11kV Grid site and a separate 33kV Switchouse where control equipment can be or already is housed within other buildings on the site. Whilst standardisation of civil design aspects is preferable, it is accepted that each project is specific. It is essential therefore that the civil design, whilst incorporating the requirements of this document, assesses each project design on its merits. The designer must have due regard at all times to designing a substation that complies with all current UK Power Networks legislation and legal requirements. Third party considerations, developers, local authorities etc., may influence the adopted design together with specific designers risk assessments, but it is essential that the requirements of this document are embedded within the final design.




2.0 DESIGN CONSIDERATIONS

Whilst this document covers the key civil engineering design requirements of an electrical substation, the designer must have due regard for basic design elements.

2.1 Functional Requirements

The principal function of the civil design is to provide buildings, structures and infrastructure to house and support the electrical equipment and ensure a safe environment for operational staff that work within the substation and general public safety.

2.2 Life Span

Design principles adopted and materials specified shall ensure buildings and structures have a life expectancy equal to or greater than the electrical equipment housed.

2.3 Future Maintenance

The designer shall consider all future maintenance requirements to ensure future maintenance will be minimal and access restrictions and future risk to operational engineers is considered. In accordance with Construction (Design and Management) Regulations 2007 (CDM 2007) the designer shall consider the safe construction, maintenance, operation and demolition of the structure in addition to the installation and removal/replacement of all plant.

2.4 Legislation

The substation must be designed to the current UK Power Networks standards and European and British legislation. The design must also comply, where possible, with current British Standards, Building Regulations and Town and Country Planning Act. It may be possible to claim general permitted development rights for substation development under the Class G, Section 17 of the Town & Country




Planning (General Permitted Development) Order 1995 where a similar site or building already exists.

Exemption from Building Regulations may be claimed under Section 4 of the Building Act 1984 and, where space permits, Schedule 2, Regulation 9 of The Building Regulations 2000 for Class II buildings except where the building is to be used as an office or dwelling. It is understood that Section 5 of the Sustainable & Secure Buildings Act 2004 removing this exemption for works carried out by Statutory Undertakers has yet to be implemented by the Secretary of State.

2.5 Environment 2.5.1 The designer must have due consideration for the local environment, both in

rural and urban environments. Consultations must be sought with the Environment Agency, the Local Authority and, where appropriate, local wildlife or environmental groups to ensure the design is compatible with current legislation.

2.5.2 It is also advised that a noise survey and assessment of noise impact be carried out as part of the planning of the substation. This will allow the establishment of a baseline noise level from which to measure any future noise increases and the assessment of noise impact from the installation prior to construction will help establish whether noise suppression in the form of transformer enclosures or screening is required.

2.5.3 In order to ensure that foundations suitable for the ground conditions are designed fully a full and suitably extensive ground investigation of the site shall be carried out; this will also identify any soil contaminants that will need to be dealt with as part of the substation construction process.

2.5.4 As part of the process of assessing environmental issues the designer must consider any potential impact historic structures or ecologically sensitive areas. These include Scheduled Ancient Monuments, Sites of Special Scientific Interest (SSSI), Areas of outstanding Natural Beauty (ANOB), nature reserves and protected areas for birds. For a full list of environmentally sensitive areas see UK Power Networks policy HSS 01 027 “Protection of the Natural and Built Environment, Including Wildlife, Water and Historic Features”.




2.6 Operational

The civil designer must ensure the design is in accordance with all the UK Power Networks operational requirements.

2.7 Health and Safety

The designer must comply with the Construction Design Management (CDM) Regulations 2007 and all other relevant Health and Safety Legislation.

2.8 Electrical Apparatus

The design shall comply with all the technical and safety requirements of the apparatus to be housed. All LV electrical installations shall comply with BS 7671 IEE Regulations and a compliance certificate must be obtained. The compliance certificate shall be retained on file, recorded on the Ellipse database and, where possible, a copy displayed on site. The Civil designer must consider the installation of the electrical apparatus within the layout and design of the buildings and structures.

2.9 Cable Entries and Routes

Due regard and co-ordination of cable entries must be considered within the design, which can affect setting out and orientation of the proposed substation.

2.10 Security Prior to the commencement of any design work EDS 07-0101 Security

Specification for UK Power Networks Operational Sites and UK Power Networks Company Security should consulted in order to assess the degree and specification of security equipment required on site during both construction and operational periods.

2.10.1 Site security is imperative to safeguard the building and its equipment from

damages, theft, vandalism and also to safeguard against unauthorised




access to high voltage equipment. In order to ensure that adequate security is planned for and designed in it is important to liaise with UK Power Networks Company Security as early as possible during the project.

Where possible and safe to implement the substation shall be designed with a single point of entry; all other doors and emergency exits shall be opened from the inside only with panic bars and shall have no external locking mechanism.

2.11 Flooding

When considering the location of a new substation site it is essential, as well as considering the ecological impact and design suitability, that the risk from future flooding is assessed. Flooding can be caused by the rise of watercourses, breaches of Coastal defences and from surface water run-off and these factors need to be investigated as part of the design process. When assessing flood risk the all of following steps should be taken as a minimum:

Consider local and historical information about the site. Is the site known to

be in a flood risk area, has the site been flooded before? Investigate the surrounding area. Is the site close to a watercourse, however

small? Is the surrounding land higher than the site? This could cause flooding from surface water run-off. Is the surrounding area likely to be developed / redeveloped in the future? This again could impact on the degree of surface water run-off that could affect the site; hardstanding / hard landscaping in place of grassed/ soft landscaped areas will reduce the time and in which surface water reaches the site and is also likely to increase the volume affecting the site.

Establish whether the site is within a known flood risk area from major watercourses. As part of the initial investigation the Environment Agency website provides maps indicating areas and degree of flood risk. The flood maps site can be accessed via www.environment-agency.gov.uk and typing in the post code of the potential site (or a nearby road) into the search box under the Flood Maps section.

If it found that the proposed site is affected by flooding from any of these potential causes then ideally an alternative site should be sourced. In real terms, however, this can not always be achieved and it therefore becomes




essential that measures are put in place within the design in order to provide mitigation against the effects of flooding. Reference shall be made to EDS 07-0106 Substation Flood Protection for additional information regarding flood assessment and protection. The mitigation of the effects of flooding shall be included in the Substation design process. The local government policy PPS25 should be consulted for guidance on the rules governing the construction of new substations within flood plain areas. Information regarding flood risk and levels can be obtained from the local Environment Agency office which can be contacted for all UK Power Networks licensed areas as detailed in EDS 07-0106.

2.12 FIRE RISK ASSESSMENT In compliance with the Regulatory Reform (Fire Safety) Order 2005, for all

Grid and Primary Substation buildings, a competent and responsible person must make a suitable and sufficient Fire Risk Assessment of the risks to which relevant persons are exposed for the purpose of identifying the general fire precautions he needs to take to comply with the requirements and prohibitions imposed on him by or under the Regulatory Reform (Fire Safety) Order 2005. It is essential that the Fire Risk Assessment and the Fire Plan mentioned below are developed in conjunction with the local Fire Brigade representative.

Information concerning current legislation and minimising fire risk is

available in EDS 07-0116 Fire Protection Standard for Operational Sites, HSS 01 055 shall be consulted for guidance regarding the completion of Fire Risk Assessments (FRA).




3.0 STANDARDIZATION AND GENERIC CIVIL DESIGN

Where possible the UK Power Networks generic design must be adopted on all civil design projects. Specific design considerations or risk assessments may determine alternative designs or variations to the Standard layout. In order to comply with UK Power Networks’ Design Assurance and Audit processes these alternative designs or variations shall be documented and justified. The drawings pertinent to the design and construction of 132/33kV Grid or 33/11kV Primary Substations are listed in the relevant drawing lists issued in conjunction with this document. Above ground 132/11kV Substations will require the use of a combination of Grid and Primary Substation drawings. Drawings referring to the Building Services layouts of Grid (33kV) and Primary (11kV) Switchouses detailed in Appendix A are listed relevant drawing lists issued in conjunction with this document.




4.0 SITE LAYOUTS AND BUILDING CONFIGURATION

132/33kV, 132/11kV and 33/11kV substations comprise of the combination of a Switch House with Transformer Bay(s), complete with, where required fire separation wall(s) and security fencing. An access road, together with pedestrian circulation areas and a general finish of chippings externally. The design shall provide for small-bore foul and surface water drainage, electrical and plumbing services. The combination of buildings and structures will be project specific and variable depending on the electrical requirements of the site. In addition the land area and land shape available may dictate the site layout and building configuration. Switch Houses and Transformers can be separated by distance, mainly for fire separation or be together divided by physical fire barriers. The civil generic design drawings show examples of different site layouts and building configurations to be considered at the option-engineering phase of the project. Future electrical requirements are to be considered and the civil designer may need to allow for additional electrical equipment within the design, i.e. space for future switchgear or transformers.




5.0 GENERAL LAYOUTS AND REQUIREMENTS OF BUILDINGS, SWITCH HOUSES, CONTROL

ROOMS AND RELAY ROOMS

5.1 General

The primary function of any building within an electrical substation is to house electrical equipment. It will be the specification of the electrical apparatus that dictates the basic size and parameters of the building design. UK Power Networks procures various manufacturers of switchgear and relay panels etc. each with their own requirements that the civil designer shall accommodate. The following sections highlight the general design principles of the many substation buildings.

5.2 Switch Houses – General

A typical 11kV or Replacement 33kV Switch House shall house 2 principal rooms:-

Switchgear Room Auxiliary Room (including room for batteries)

A stand alone 33kV Switch House (where there are no other buildings

on site within which the control equipment is / can be housed and there are no existing welfare facilities), normally associated with 132kV/33kV or 132/11kV Grid sites, will require an L.V.A.C. and telecom room, mess room, washroom, toilet and store room in addition to the rooms outlined above. Where Plante cell batteries have been specified it will be necessary to specify a separate battery room details of which are given in Section 5.8. Where VRLA batteries have been specified a separate Battery Room is not required.

Certain 11kV and 33kV switchgear will dictate a cable basement requirement under the switchgear room. Refer to Section 5.5. All switch houses shall be designed to a minimum 1 hour fire rating but a fire assessment shall be undertaken on each project.




5.3 Switchroom

5.3.1 The switchgear type and number of panels will dictate the size of the switchroom.

5.3.2 The minimum clearances for various switchgear types are highlighted in the

manufacturers’ literature and accommodated on the generic layout drawings. 5.3.3 Standard construction is either a screeded pre-cast concrete panel floor,

brick/block cavity wall portal frame and insulated steel cladded roof or insulated steel cladding fixed to the portal frame with insulated steel clad roof.

5.3.4 The entire switchgear room must be designed to support the weight of the

switchgear such that equipment can be manoeuvred into the final position.

5.4 Cable Trench and Switchgear Support

5.4.1 All switchgear is to be fully supported on an independent galvanised steel frame separate from the concrete floor slab. Alternative system is to fix switchgear onto unistrut system set in the floor slab.

5.4.2 Different cable entry techniques into the procured switchgear will have an

effect on the cable trench design. The cable trench shall be reinforced concrete of sufficient density and water tightness to prevent dampness on the internal surfaces. Using the Elevated and clad switchouse option the basement can be above ground and open to the air; in using this option the Designer must ensure that the underside of the switchgear is sealed against ingress of moisture and dust.

5.4.3 Cable trench to be 1350mm minimum depth. It may be necessary to increase this depth to suit the cable radius or cable connection to switchgear (see Section 5.5 also).

5.4.4 Cable trench to house slab to be laid to falls and have an externally accessed

sump.

5.4.5 Cable entry points shall be plastic walled ducts to suit cable size and number.




5.4.6 Trench covers to be 25mm anti-slip GRP, flame retardant, on galvanised mild

steel frame. Covers shall be fitted such as they are easily lifted without binding against adjacent covers and individually located.

5.4.7 Switchgear support framework must be constructed and installed to the

electrical equipment manufacturers recommended level line and flatness tolerances. Cable cleating to be considered within frame design, together with possible effects of eddy currents.

5.5 Cable Basement 5.5.1 Certain 11kV and 33kV switchgear dictate that a full cable basement shall be provided over the full area of the switch room in lieu of a cable trench.

5.5.2 Basement headroom is dictated by cable entries, but a minimum of 2100mm

clear headroom shall be achieved.

5.5.3 Below ground cable basements to be designed as water excluding structures.

5.5.4 Entry to below cable basement to be a permanent staircase with additional escape route to minimum escape distances, in accordance with the Building Regulations. Where possible basement access/egress to be via external doors. Ground level cable basements are to be enclosed with an open mesh security fence with access gates diametrically opposite each other.

5.5.5 Floor to be finished to falls to perimeter drainage channels, to intercept

ground water infiltration. Drainage channels to discharge into externally accessed sump.

5.5.6 Cable basements shall be assessed for compliance with Confined Space

Regulations. UK Power Networks’ Confined Space entry procedures shall be adhered to when accessing a cable basement.

5.5.7 All cables and unused ducts passing through the external walls to be sealed

using a UK Power Networks Approved Sealing System.

5.5.8 Cable basements to have natural ventilation where possible otherwise forced ventilation is to be considered.




5.6 Auxiliary Room

A separate ‘Auxiliary Room’ is preferred for three principal reasons. a) Provides a safer working environment. b) Permits access to control panels if the switchgear is in fault conditions.

c) Protects UK Power Networks Engineers in the event of switchgear failure.

5.6.1 A full height solid blockwork wall shall separate the Auxiliary Room from the Switchgear Room with a single 1 hour fire-rated access door, with vision panel, between the rooms.

5.6.2 External access to the Auxiliary Room shall be incorporated within the design

with a single access door.

5.6.3 The Auxiliary Room is to be provided with an anti-static raised computer floor of 600mm x 600mm modular panels, supported 600-900mm above the structural floor. Pedestals to be mechanically and resin fixed to sub floor slab and inter-linked at top level.

5.7 L.V.A.C. and Telecom Room (Stand alone 33kV Switchouse Only) 5.7.1 Within a 33kV Switchouse a separate room shall be allocated for L.V.A.C. and telecom. 5.7.2 External access to the room shall be incorporated into the design.

5.7.3 Floor to be provided with an anti-static raised computer floor of 600 x 600mm modular panels, supported up to 900mm above the structural floor. Pedestals to be mechanically and resin fixed to sub floor slab and inter- linked at top and bottom levels.




5.8 Battery Room (*not generally required with VRLA sealed batteries) Only where sealed VRLA batteries are not used a separate battery room shall be required: 5.8.1 Batteries shall be segregated from other equipment in a separate room of fire resisting construction with a full height wall to the underside of the switch house roof. 5.8.2 If at all possible battery rooms shall be sited adjacent to an outside wall so

as to facilitate the provision of natural ventilation and the room to be bunded to contain any spillage, including raised door threshold.

5.8.3 Ceilings shall not have unventilated recesses in which hydrogen may

accumulate, e.g. between ceiling beams. Ceilings shall therefore be flush and preferably sloped upwards toward the point of ventilation outlets especially if wall mounted.

5.8.4 The use of false ceilings is not permitted.

5.8.5 Ventilation to be in accordance with the battery manufacturers

recommendations. Forced ventilation is not recommended, due to possible failure of system. Therefore, natural ventilation is preferred.

5.8.6 Ventilation outlets shall either be installed in the ceiling or where this is not

practicable, immediately below ceiling level and communicate as directly as possible with the open air. Openings shall be large enough to ensure adequate air movement and where practicable be terminated in an extractor cowl. Louvre vents are preferred to air brick openings to provide an unrestricted path for air or gases.

5.8.7 No holes shall be left in inside walls, particularly at ceiling level which would

allow hydrogen to escape into other rooms. Trunking shall not pass through inner walls at a height greater than 1.25m from the ceiling and then only if unavoidable.

5.8.8 Low level inlets shall be installed such as to aid a cross flow of air over the

batteries; thus dispersing any hydrogen evolved. It may be appropriate to install low level louvres in internal walls or doors.




5.8.9 Batteries shall be positioned either below high level outlets or in the air path between air inlets and outlets.

5.8.10 Ventilation ducts, if required, shall be designed to prevent the accumulation

of hydrogen, e.g. avoid “U” bends in the vertical plane. Ducts shall be non-combustible and acid resistant. If metal ducts are used they shall be acid resistant lined.

5.8.11 Natural ventilation shall be the first consideration but if mechanical

ventilation is necessary, intrinsically safe fan motors shall be situated in a safe atmosphere with no risk of hydrogen infiltration.

5.8.12 All electrical installations and switches within the battery room are to be

intrinsically safe

5.8.13 Floors shall have an acid resistant floor finish.

5.8.14 A hand basin shall be provided within the battery room for emergency use. Size to suit site requirement.

5.9 Washroom / Toilet The requirement for a toilet and washbasin is to be carefully considered prior to designing into the installation. Toilet and washing facilities have to be inspected regularly and water tanks are a potential source of Legionella particularly if infrequently used. If the site has an existing facility or another site within 20 minutes drive has toilet and hand washing facilities then the provision of a new toilet and basin do not need to be considered in the design. If it is found that the site does require toilet and handwashing facilities to make it complaint with the Workplace (Health, Safety & Welfare) Regulations 1992 then the following specification shall be complied with: 5.9.1 A single washroom is to be provided with either an external steel security door or, if the washroom is to be accessed from the Auxiliary Room, an internal minimum ½ hour fire-rated timber or steel door. 5.9.2 The washroom to comprise of a stainless steel hand wash basin with ‘cold’

pillar tap and a low-level glazed pedestal w.c.

5.9.3 Install 110mm internal soil stack with air admittance valve.




5.9.4 7.5 Litre, 3kW storage water heater plumbed to cold water service.

5.9.5 Provide white ceramic tiled splash back behind basin, min. 300mm high above sink and extending min, 150mm either side of basin.

5.9.6 All cold water service pipes to be fitted with isolating valves and shall be

earthed.

5.9.7 Ventilation to washroom to be ventilated to comply with the current Building Regulations.

5.10 Store Room (Stand alone 33kV Switchouse Only) 5.10.1 Store room is to be provided to house general equipment used by the operational engineers, e.g. barriers, signs etc. Approximate area 10m2. 5.10.2 Access via external steel security door.

5.11 Mess Room (Stand alone 33kV Switchouse Only)

5.11.1 Mess Room to be provided for maintenance and commissioning teams. 5.11.2 Fitted with plumbing, sink unit and other services to enable preparation of food and beverages.

5.11.3 Fitted with table and chairs for a minimum of four people.

5.11.4 Provide white ceramic tiled splash back behind basin, min. 300mm high

above sink and extending min, 150mm either side of basin.

5.11.5 All cold water service pipes to be earthed and fitted with isolating valves.

5.11.6 Ventilation to mess room to comply with current Building Regulations




6.0 SWITCH HOUSE ELEMENTS AND MATERIALS

6.1 General

The design and specification of materials for the key building elements could be dictated by third party influences, such as developers or the Local Authority. The generic design drawings depict the preferred construction techniques of UK power Networks. This section specifies the preferred construction materials to be used when designing a switch house.

6.2 Foundations

6.2.1 Reinforced concrete raft foundations and walls below ground level shall be

designed to suit the formation level of the cable trench or basement.

6.2.2 The foundations to be designed to suit the local ground conditions and building loads applied.

6.3 Walls 6.3.1 All external walls to be:

a) brick/block cavity walls with approved rigid cavity insulation built- in during construction. 100mm facing brick to suit developer or L.A. planning conditions or to match adjacent buildings and structures. Internal walls to be 7 N/mm2 blocks with fair face finish. Thermal “U” value to meet the current Building Regulation requirements. Lightweight air-entrained concrete thermal blockwork is not acceptable. or

b) Cladding matching that of the roof and where thermal properties and security equivalent to the brick / block construction can be maintained. Rails or other fixings must be provided internally to facilitate the installation of heating lighting and other wall mounted units.




6.3.3 No windows allowed. 6.3.4 No projecting corners of brickwork or climbing aids to be incorporated into

the design.




6.4 Roofs 6.4.1 The roof construction shall be insulated profiled colour coated cladding,

composite or built up, supported on a portal frame, at a nominal pitch of 10 degrees, subject to design and cladding type. No roof lights allowed.

6.4.2 Flat roofs should only be used on brick/block acoustic housings to

transformers, when extending existing flat roof buildings or when Local Authority planning requirements stipulate.

6.5 Finishes

Basic finishes are to be applied as follows- 6.5.1 Floors

Switchgear Room Floor

-

Concrete screeded, sealed and painted with heavy duty floor paint.

Auxiliary Room

-

Anti-Static Raised Access Floor

LVAC & Telecom Room (33kV Switchouse only)

-

Anti-Static Raised Access Floor

Battery Room (see Section 5.8)

-

Acid resistant floor finish with 150mm skirting and raised threshold.

Washroom / Toilet (see section 5.9)

- Sealed and painted with heavy duty floor paint.

Mess Room - Vinyl floor or heavy duty floor paint

6.5.2 Walls – Decoration internally, vinyl matt emulsion – Magnolia (1 No.

thinned mist coat, 2 No. neat coats). 6.5.3 Ceilings –vinyl matt emulsion – White (1 No. thinned mist coat, 2 No.

neat coat).




6.5.4 Doors – depending on any planning conditions or developer requests, external door colour to be sympathetic to external brickwork or cladding.

6.6 Doors

External doors – all double and single leaf egress doors to be insulated steel security, double skin doors. The preferred construction shall be assessed to ensure that, as a minimum, all items within Clause 6.6.2 are considered. 6.6.1 External substation doors to switch houses shall be constructed to

provide a minimum 1 hour fire rating, with panic exit furniture. 6.6.2 Reference shall be made to the following criteria:-

(a) Escape from fire; provision of doors, maximum escape distances (b) Planning or developers considerations (if applicable).

(c) Security of Buildings.

(d) Emergency Exit.

6.6.3 Double doors for switchgear. Doors are to be of sufficient width and

height to accommodate installation of switchgear panels. Hinged transom over panels are permitted but must not be removable.

6.6.4 Security doors to be compliant with appropriate government SEAP or

Loss Prevention Certification Board LPS 1175 standards.

6.6.5 Internal doors are to be minimum 1 hour fire rated steel doors with a viewing panel with the exception of the internal toilet door (where required) where the viewing panel shall be omitted.

6.6.6 Where possible and safe to implement the Switchouse shall be

designed with a single point of entry; all other doors and emergency exits shall be opened from the inside only with panic bars and shall have no external locking mechanism (see also Sections 2.10.1 & 2.10.2).




6.6.7 All steel doors are to be connected to the main substation Earth in accordance with UK Power Networks’ Earthing Manual.

6.7 Internal and External Stairs Internal and external stair rises, goings and pitches should be dimensioned in accordance with BS 5395-1:2000, Table 1, Stair Category A. All stairs and walkways to be designed in accordance with BS 5395-1:2000. 6.8 Thermal Insulation

Thermal insulation shall be incorporated to ensure minimum “U” values as recommended within the current Building Regulations.

6.9 Building Services 6.9.1 For the required Building Services within the 33kV/11kV Primary and

132/33kV Grid substation refer to the UK power Networks Building Services Specification in Appendix B of this Code of Practice. All LV electrical installations shall comply with BS 7671 IEE Wiring Regulations. The Building Services Specification document in Appendix A includes the following items:-

(a) Distribution boards and associated equipment/cabling.

(b) Internal lighting scheme together with all lamps to all areas.

(c) Emergency lighting installation.

(d) General power distribution.

(e) Space and water heating installation including equipment.

(f) Dehumidification installation.

(g) External amenity lighting.

(h) Floodlighting to transformer bays.




(i) Earthing, bonding, testing and commissioning.

(j) Provision of installed drawings, manuals and test certificates.

7.0 TRANSFORMER BAYS

7.1 General 7.1.1 Reference shall be made to the UK Power Networks generic drawings

for the fundamental design philosophy of a transformer bay. 7.1.2 In principle, a transformer shall be sited on a concrete plinth within

an integral concrete bunded area designed to contain the oil within the transformer in the event of a spillage or disruptive failure.

7.1.3 The area of a transformer bay will be dictated by the minimum

acceptable clearances around the transformer and coolers or to the distances of possible future acoustic walls located to avoid standing waves, whichever is the greater.

7.1.4 Bund walls to be a minimum 250mm thick although this may need to

be widened to allow a palisade fence to be surface fixed if required. It may be necessary to widen the wall locally where removable palisade fencing is to be used or where there is a possibility of a future requirement for an acoustic housing (see 7.1.7).

7.1.5 Bunded area to be finished with 20-40mm graded, clean washed

rounded natural stone. For oil containment calculations it can be assumed that 1m3 of this stone will contain 300 litres of oil (see also Section 7.4 Oil Containment of Transformers).

7.1.6 Cables to enter into a cable pit via cable duct penetrations. Cable pit

to be designed to retain sand fill in the event of excavating for cables and to receive lean mix concrete cover slab.

7.1.7 Where site conditions dictate Transformer bays may have to be

designed to accommodate future construction of an acoustic enclosure (see section 7.2).




7.1.8 Transformer bay sump to house discriminator pump to remove surface water from bunded area and to detect presence of oil.

7.1.9 Transformer bay design to allow for forces exerted by temporary

pulling eyes to assist the delivery of the transformer. Fixed to either the transformer plinth or the bund walls. Maximum pulling forces to be within S.W.L. of the transformer turfer.

7.1.10 Fenced transformer bays shall have two pedestrian gates for

access/egress.

7.2 Noise and Acoustic Housings

7.2.1 All transformers generate noise, the principle component being a continuous tone of 100Hz. After considering minimum safe clearances for operation and maintenance of plant the transformer bay should be designed to avoid constructive wavelengths (λ) for frequencies of 100, 200, 400 and 800Hz. Constructive wavelength distances that can contribute to the noise level are considered to be λ/2, λ and 2λ or multiples thereafter.

Generally, in order to avoid constructive waves, the distance between the transformer tank, walls and any roof soffit should fall between the following figures:

0.915-1.040m, 1.345-1.600m, 1.750- 1.980m and multiples thereafter.

7.2.2 The more irritating rattles due to loose nameplates, loose valve

locking pins, tap changes, etc., are be easily eliminated by tightening.

7.2.3 Noise can only be airborne, but it must be remembered that ground-

borne vibrations may be re-radiated as noise by some other structure.

7.2.4 It is current practice to design transformer bays with the provision for future noise reducing housings for electrical plant.




7.2.5 Each site shall be assessed for noise pollution and agreed with the Engineer and where applicable the Local Authority, if provision for a transformer housing is required.

7.2.6 Pre and post construction noise surveys shall be considered for all

substation developments, particularly those being carried out adjacent or within view of residential areas.

7.2.7 Noise reducing housings/enclosures – if after a risk analysis a noise

reducing housing is required; consideration must be made to its construction. Typical construction method being either traditional built brickwork or a proprietary prefabricated acoustic enclosure.

Enclosures are generally required in residential areas and therefore subject to planning constraints/conditions and required to be sympathetic with surrounding structures. Walls shall be located to avoid standing waves and minimum clearances constructed of dense masonry. Roofs shall be constructed in a suitable dense material eg proprietary PCC flooring / roofing system.

Consideration must be given to a removable panel within the housing to remove the transformer and coolers without the need to demolish the full housing. All housings or enclosures are to be designed to a minimum 1 hour fire rating. Where a transformer is to be located within another building or where it is within close proximity to vulnerable buildings and places of public assembly (not including footpaths) the enclosure shall be designed to a 4hr fire resistance rating. Minimum separation distances for specifying “close proximity” and the fire resisting requirements of any roof to the enclosure shall be determined using the guidance in EDS 07-0116. Two sound attenuating doors are required per enclosure, opening outwards with panic bars and to the appropriate fire rating (1 or 4 hours as applicable), diagonally opposed. Acoustic weatherproof ventilators are required in the housings located at high level and low level diagonally opposed.




7.3 Segregation of Transformers

7.3.1 Where applicable a minimum clear distance of 8m between transformers or a transformer and any other oil-containing equipment and/or a control room shall be incorporated into the design.

The minimum separation between items of equipment and equipment and building shall be determined using the information contained in EDS 07-0116 Fire Protection Standard.

7.3.2 Where clear distance between transformer and other essential

equipment and/or buildings cannot be achieved, a firewall separation barrier and/or fire quenching system shall be constructed.

7.3.3 Each site shall be assessed to determine the extent of works required

regarding fire separation.

7.3.4 The height of a fire separation wall shall be at least 1m higher than any oil containing equipment, i.e. conservator tank or radiator and extend 2m in length past the end of the transformer and cooler.

7.3.5 Firewall construction shall be a 4 hr barrier solid brick, concrete or

flameproof partition.

7.3.6 In order to minimise the possibility of the spread of fire there is to be no opening or duct route between the transformer bays.

7.3.7 The routing of control cables and multicore services though one

transformer bund from another is not permitted.

7.4 Oil Containment of Transformers

7.4.1 Scope

The Water Resources Act 1991 states that it is an offence to cause or knowingly permit the discharge of poisonous, noxious or polluting matter into relevant waters or into any underground strata (clause 85(1)). This is applicable regardless of the size of the container or the purpose of the polluting substance and the fines and possible




custodial sentences set in this Act, The Environmental Protection Act 1990 and The Environment Act 1995 can be imposed for any polluting incident. Bearing in mind the statutory requirements, this document lays down the practical steps which shall be taken to contain the accidental leakage or spillage of significant quantities of oil in a substation.

7.4.2 Principles of Oil Containment

An assessment of oil containment shall be made of all oil filled equipment, including the decommissioning of existing and delivery of new, particularly if there is a risk of oil leakage into the ground or added protection is needed for local water courses. The principle is that all plant containing oil shall be contained within a completely bunded area.

7.4.3 Measures for Containment of Oil

In accordance with Control of Pollution (Oil Storage) (England) Regulations 2001 and the Environment Agency guideline PPG2 a continuous bund wall shall surround the oil filled equipment and shall be sealed by means of an impervious base set at such a depth as to retain 110% of the total quantity of oil present in plant. For calculation purposes one cubic metre of 20-40mm sized shingle retains 300 litres of oil.

7.4.4 Discriminator Pump to Remove Accumulated Rainwater

An oil discriminating pump within a sump is to be supplied with 1.8-2.1 l/s capacity. This shall discharge into an oil interceptor (see below) installed of suitable size for the drained area and pump discharge rate before a local soakaway or watercourse subject to approval of the Water Authority/Environmental Agency. Oil discriminator pump facility alarms are to be connected to UK Power Networks remote monitored control SCADA systems.




7.4.5 Oil Interceptor The choice of Full Retention oil interceptor is to be in line with Environment Agency policy document PPG 3. Of the two Classes of Oil Interceptor, Class 1 Interceptors are required when discharging into surface or controlled waters, Class 2 Interceptors are required when discharging into foul sewers.




8.0 ALUMINIUM AND STEEL SUPPORT STRUCTURES AND FOUNDATION 8.1 Structure Design

The structures shall be delivered to site complete with all pre-drilled holes for fixing of earth tapes, cables and all other relevant attachments. In addition, where required, they shall be supplied with suitable drain holes. Site drilling after erection shall not be permitted.

Structures shall be used for bonding of electrical equipment to an earth mat and evidence shall be provided which demonstrates that the structure is capable of withstanding the rated short time current. The design of support structures shall comply also with the requirements of all UK Power Networks relevant Codes of Practice and British and European Standards.

8.2 Serviceability

When considering the serviceability of the supporting structures, the contractor shall ensure that deflections are appropriate for the proper function of the structure and for the plant and equipment supported by the structure but in any case, shall not be greater than that recommended in the appropriate British and European Standards.

8.3 Finishes The finishes applied to structural steelwork elements shall have a uniform appearance and shall be appropriate for the level of corrosion protection for the required 40 year design life of the substation. The holes drilled in the structure to accommodate the galvanising process shall be fitted with suitable plugs.

8.4 Foundation Design

The foundations to support structures shall be designed to adequately transfer the moments and horizontal and vertical forces generated by the structures to the ground at formation level. Forces and moments generated




at the base of the support structure shall be provided to the civil designer for the purpose by the support structure manufacturer.

The foundations shall be sufficiently large in plan area and depth to accommodate the structure holding down bolts, and shall be designed to ensure that overall and differential settlement of the ground below the structure foundation lies within the tolerances specified either by the electrical designer, the support structure manufacturer and/or the electrical equipment manufacturer. The foundations shall be designed to provide adequate strength, stability and durability for the anticipated service life of the substation and for the site conditions in accordance with the appropriate design standards and Codes of Practice.




9 EXTERNAL WORKS

9.1 Site A substation site must satisfy the following requirements: (a) Provide sufficient space for the ultimate envisaged number, size and

layout of plant and buildings. (b) Provide adequate access for the largest indivisible loads envisaged

and adequate and safe personnel access and exit. This includes assessing service roads and highways not controlled by UK Power Networks providing an access route to the site boundary gate.

(c) Provide adequate space for the maximum envisaged number and size

of overhead line and/or underground cable entries.

(d) Must be capable of complying with the detailed planning requirements of the Local Authority, including amenity aspects. At the same time it must not be so large, beyond the substation requirements, as to require expensive treatment of the unused portion of the land.

(e) Consideration shall be given to the environmental impact of

developing each particular site.

9.2 Roadways/Pedestrian Access

9.2.1 A suitable access roadway for plant delivery and for general access into the site will be required. This access will need to accommodate:

(a) Delivery / removal of Transformers. (b) Delivery / removal of Switchgear.

(c) The use of articulated vehicles must be allowed for within the

design. Co-ordination with haulage companies delivering transformers is recommended.




(d) Maintenance and operational use of substation.

9.2.2 Roadway is to be constructed from a material suitable for purpose with a nominal width of 4500mm.

9.2.3 Road layout to include provision for turning area for maintenance

vehicle.

9.2.4 A 1200mm wide pedestrian paved footpath to be laid from roadway to main doors of switchroom.

9.3 Fencing

It is essential, in order to be effective, that boundary and compound fencing or wall is designed and constructed without any external climbing aids.

9.3.1 Application

9.3.1.1 Wherever possible the site shall be surrounded by fencing which presents a clear view of the enclosed space as a deterrent to unauthorised interference.

9.3.1.2 Where high voltage conductors are exposed in a

substation, a security fence of types as shown in Table 1, constructed to UK Power Networks specification and in accordance with the Electricity Safety, Quality and Continuity (ESQC) Regulations 2002 shall be installed.

9.3.1.3 Consideration shall be given to the use of removable

posts and panels in place of gates where access is only required for transit of fixed plant.

9.3.1.3 A 2m clear zone external to the site security fencing line

shall be maintained to minimise third party compromising the statutory fence height. The site boundary, which shall include the 2m clear zone, shall be permanently and clearly defined.

9.3.1.4 All fencing and enclosure of substations shall be in

accordance with Part III Substations (Clause 11) of the




Electricity Safety, Quality and Continuity (ESQC) Regulations 2002.

9.3.1.5 External boundary and internal compound fencing shall

be constructed so as not to provide any climbing aids.

9.3.2 Amenity Fencing

9.3.2.1 Fencing provided to meet covenants or planning authorities’ requirements shall:

a) Be the minimum standard to meet those

requirements, having due regard to maintenance costs.

b) Provide minimum screening effects to discourage

unauthorised interference, combined with reasonable resistance to vandalism. Graffiti proof surfaces are preferable.

9.3.2.2 In view of the varying requirements of planning

authorities and the desirability of avoiding a clash of appearance with the surrounds no standard is set.

9.3.3 Security fencing

9.3.3.1 The minimum acceptable specification shall be based on risk assessments of the proposed site using one of the following fence types, with a minimum height of 2.4m in accordance with Electricity Supply Quality and Continuity (ESQC) Regulations 2002.

(a) Steel palisade security fence to UK Power Networks standard. (b) Weldmesh single skin 358 mesh.




Drawings EDS 07-0105-3001 Sheets 1 to 5 and EDS 07-0105-3002 Sheets 1 to 5 provide details of the agreed standards for fencing used by UK Power Networks. (c) Fencing is to be designed and constructed such that there are no external climbing aids that could assist unauthorised entry into the site or compound areas.

9.3.3.2 There are three possible categories of site in relation to

fencing specifications (refer to Table 1), but the transformer compound must always have palisade fencing:

Ref Risk Transformer

Bund Fencing Open Terminal Compound Perimeter Fencing*

Boundary Fencing*

1 Low 2.4 high palisade fencing

2.4 high palisade fencing / 358 Weldmesh

Demarcation fence

2 Medium 2.4 high palisade fencing


Weldmesh

3 High 2.4 high palisade fencing


Palisade

Table 1 : Fencing Specification * For clarification the Site Perimeter is considered to be the outer boundary of the site within which all equipment /plant to be protected from Public interference is to be housed, the Boundary is




the edge of the 2m clear strip of land (Clear Zone) beyond the Compound Perimeter (see 9.3.1.3). 9.3.3.3 Each site shall receive its own Risk Assessment during

design to ascertain appropriate security fencing. 9.3.3.4 In addition to the risk assessment of the fence panel type,

the kerb construction can also vary to increase security, as referenced within Table 2.

REF RISK KERB* CONSTRUCTION

1 Low Concrete Kerb laid and haunched as per

Highway specification.

2 Medium Kerb laid as above with additional 600mm wide x 100mm deep R.C. anti intruder strip.

3 High Kerb laid as above with additional 750mm deep R.C. beam.

Table 2 : Fence Kerb Specification *For clarification the term Kerb refers to an HB2; 125x255x914mm PCC Straight Half Batter kerb.

9.4 Drainage

See also Section 7.4 regarding oil containment and HSS 01 007 for UK Power Networks policy on Site Drainage Systems.

9.4.1 Each substation site shall be considered on its own merits regarding

drainage design. 9.4.2 The selected site shall be thoroughly investigated to prove the

presence of drains or otherwise.

9.4.3 Where drains exist every effort shall be made to utilise same. The outfall from the Substation may be subject to permissions and




discharge consent conditions; the Discharge Consent flowchart in Section 11 of EDS 07-0110 can be consulted in determining which, if any, consents are required.

9.4.4 A system of land drainage may be installed adjacent to the building

at an invert level below cable entry level and connected into the existing surface water drainage system.

9.4.5 Surface water drainage shall include roof and road surface water plus

water pumped out of the bunded areas. A Class 1 interceptor must be used on sump discharge and road gully drainage. The Oil interceptor shall be provided with remote monitored oil alarm.

9.4.6 In the absence of any form of existing drainage the following courses

shall be adopted:

(a) Surface water shall be collected into its own system and directed into a soakaway as far removed from buildings and structures, as the site will allow.

(b) Foul drainage shall be direct into a septic tank.

(c) Surface water from the switchouse roof may be directed into a

proprietary rainwater recycling system (eg Klargester Envireau rainwater harvesting system) for use within washroom.

9.5 Transformer Delivery

9.5.1 Net transport weight of transformers can be up to 40 tonnes for

Primary 33/11kV transformers and 90 tonnes for 132/33kV or 132/11kV Grid transformers. To cater for this load haulage vehicles of the articulated type up to 18m long are used, and access roads must be constructed accordingly. Co-ordination with the haulage company employed to deliver the transformers is recommended.

9.5.2 Care shall be taken to ensure that the position of any overhead

equipment near or over the access road does not impede the passage of the loaded haulage vehicle.




9.5.3 Consideration shall be made within the design to ensure plant and equipment can be installed in a safe and satisfactory manner. The designer is advised to seek advice from the plant manufacturer and installation company.

9.5.4 Transformer plinths are preferably sited alongside a road or

temporary hardstanding. Where this is not possible the use of a crane shall be considered. If this is not practical it may be necessary to provide temporary skidways of sufficient bearing ability to carry the transformer in transit from the road to its plinth.

9.6 Switchgear Delivery

Delivery of switchgear will require off-loading and landing platforms at the building entrance. Co-ordination with the Electrical Engineer to ascertain actual requirements is recommended.

9.7 Combined Services

Due to the extent of services located within a site, drainage, cables, earthmat, building services, multicores etc., it is imperative that the setting out of all underground services are co-ordinated and recorded as installed. Where possible, services shall be routed away from areas that may be used for heavy equipment during the construction phase. If this is not possible suitable protection shall be provided. Cable routes shall be located to avoid the undermining of the sub-base to the site roads when excavated.

9.8 Ground Finishes

9.8.1 All ground surfaces within the substation perimeter fence to be covered with 100mm depth of 20mm down, clean washed natural, (rounded where possible), shingle on porous geo-textile membrane.

9.8.2 Within the 2m clear zone external to the site security fencing light

weight clinker, pea shingle or similar to be used.




10 EXISTING SITES

10.1 When carrying out alterations and modification works within existing substation buildings where some or all existing plant and cables remain LIVE, careful consideration must be given to:-

(i) Creating a safe working area (temporary partitions); (ii) Protection of plant and cables against damage; (iii) Preventing the existing environment in the ‘Operational’ portion of sites from

deteriorating; (iv) Vibration damage (mal-operation of Relays, etc); and (v) Continuous safe and easy Operational Access to UK Power Networks and

other authorised staff. 10.2 Alterations to existing structures and buildings will be carried out to match

existing finishes and details, unless a significant improvement to the performance of the structure can be achieved by utilising alternative or improved construction techniques and materials.

10.3 When carrying out works at existing sites, an assessment of the

condition of the entire site and existing structures shall be made with respect to continued site life span. Any works over and above the project requirements identified shall be presented to the UK Power Networks Project Manager or Senior Project Manager for consideration.

11 EARTHING

11.1 Reference shall be made to the Earthing Standard Manual and ENA Engineering Recommendation C55/4. Design by a specialist consultant may be required.

11.2 The Earthing system is to be installed at the same time as the foundation

construction works by the Civils contractor or by a specialist sub-contractor. The Earth tape and rods are to be protected from damage at all times.




11.3 In accordance with IEEE 80 and Section 3 of the Earthing Standard Manual the steel reinforcement in the structure foundations is to the bonded to the Substation Earthing system.

11.4 A Lightning Protection System (LPS) must be designed and installed in

accordance with BS EN 62305-1:2006 Protection against lightning. The LPS must be linked to the main building Earth in order to prevent arcing during lightning strike conditions but is to have its own dedicated Earth rods.

11.5 40x4mm Copper tape or 70mm2 stranded copper to be utilised unless

otherwise stated. Tape to be fixed to structures with 8mm Ø x 40mm stainless steel fixing pins at 300mm centres.

11.6 In high risk areas or sites considered likely to be vulnerable to unauthorised

entry and theft shields to protect the Earth tape from theft or unauthorised interference are to be considered subject to a security assessment. “Guardian” shields and the fixings are available from Alcomet Ltd, Unit 5, Gibbons Industrial Park, Dudley Road, Kingswinford, West Midlands. DY6 8XF Tel 01384 404488 www.alcomet.net

12 FURNITURE

Allowance in design to be made for an engineer’s desk with chair and a 4-drawer filing cabinet.

13 HEALTH AND SAFETY AND ENVIRONMENT

13.1 The designer’s role in Health and Safety throughout the Project

All designers shall undertake their duties in accordance with current Health and Safety legislation and CDM 2007, including: (a) Making clients aware of their duties. (b) Giving due regard to health and safety in the design work.

(c) Providing adequate information about the residual health and safety

risks associated with carrying out and completing the project and any operational risks e.g. confined spaces.




13.2 Designer’s Risk Assessments / Hazard Elimination and Management List

(HEML) Site Specific Hazard Risk Assessments must be completed for all elements of design and included as part of the CDM H&S documentation to be retained on site. For a blank template HEML see EDS 00-0002.

13.3 The designer must have due consideration for the local environment both in

rural and urban environments. Consultation must be sought with the Environment Agency and Local Authority to ensure the design is compatible with current legislation.

13.4 Since 1st July 2007 it is a requirement by law that smoking is banned in,

amongst other areas, all enclosed work places in accordance with the Health Act 2006. It is therefore a requirement for signage to be displayed at all substations in accordance with Statutory Instruments 2007 No. 923 Smoke-free (Signs) Regulations 2007 and Section 7.6 of the associated explanatory memorandum.

In summary: At least one entrance to the Switchroom and any separate ancillary buildings must display a sign with the international No Smoking symbol and the words “No Smoking. It is against the law to smoke in these premises.” All other entrances must display at least a sign showing the international No Smoking symbol. All signs must be at least the equivalent of A5 in area. The international No Smoking symbol must be at least 70mm in diameter. For UK Power Networks substations the “No Smoking. It is against the law to smoke in these premises.” sign is to be displayed on the main entrance door of each building. International No Smoking symbol signs are to be prominently displayed in each room (switchroom, auxiliary room, toilet, LVAC room etc.) within each building and enclosed area.

13.5 Health and Safety File and As-built Information Generic and site specific hazard risk assessments must be completed for all design elements and included in the final Health and Safety documentation for the substation.




Full as-built records shall be produced and shall be available at the time of hand over of the project. The Principal Contractor shall provide all information available necessary for the CDM Co-ordinator to be able to complete the Health & Safety file in accordance with CDM 2007 Regulations. Records are to include:

a) Fully marked up as-built drawings detailing all structural and dimensional details.

b) Cables and circuits within the substation are to be clearly recorded and marked on the plans.

c) Feeds relevant but external to the substation are to be also recorded. d) Maintenance periods and procedures and equipment supplier

information are to be provided for all equipment and plant. e) Hard-copy of the Health & Safety file to be made available on site.

The handover process of the project must include representatives from Network Operations and provide details of maintenance and operational requirements essential to the safe and efficient operation of the site and/or facilities.




14 REFERFENCE DOCUMENTS Ref No Document Title EDS 00-0002 Hazard Elimination and Management List EDS 07-0101 Security Specification for UK Power Networks Operational Sites EDS 07-0105 Grid and Primary Substation Civil Standards EDS 07-0106 Substation Flood Protection EDS 07-0116 Fire Protection Standard for Operational Sites HSS 01 007 Site Drainage Systems HSS 01 055 Fire Risk Assessment HSS 01 027 Protection of the Natural and Built Environment, Including Wildlife, Water

and Historic Features Earthing Standards Manual Town & Country Planning (General Permitted Development) Order 1995 Building Act 1984 Building Regulations 2000 Sustainable and Secure Buildings Act 2004 The Water Resources Act 1991 The Environmental Protection Act 1990 The Environment Act 1995 Electricity Supply Quality and Continuity (ESQC) Regulations 2002 Construction (Design and Management) Regulations 2007 Regulatory Reform (Fire Safety Order 2005 Control of Pollution (Oil Storage) (England) Regulations 2001 Health Act 2006 Loss Prevention Certification Board LPS 1175 Statutory Instruments 2007 No. 923

Smoke-free (Signs) Regulations 2007

BS 5395-1:2000 Stairs, ladders and walkways – Design Code of Practice BS 7671:2008 Requirements for Electrical Installations BS EN 62305-1:2006

Protection against lightning

PPS25 Development and Flood Risk PPG2 Above Ground Oil Storage Tanks PPG3 Use and design of oil separators in surface water drainage systems IEEE 80 Guide for Safety in AC Substation Grounding




APPENDIX A

BUILDING SERVICES SPECIFICATION




BUILDING SERVICES SPECIFICATION

FOR 33kV & 11kV SWITCHOUSES

Reviewed and Approved by:

Name Role Signature Date Mark Dunk Civil Standards Manager M. Dunk




CONTENTS 1.0 GENERAL SPECIFICATION 50 1.1 INTRODUCTION 50 1.2 SCOPE 50 2.0 TECHNICAL SPECIFICATION 52 2.1. FINAL DISTRIBUTION BOARDS AND EQUIPMENT 52 2.2 CONDUIT SYSTEMS IN GENERAL 52 2.3 STEEL CONDUIT 53 2.4 CABLE TRUNKING 54 2.5 WIRING CABLES AND FLEXES 55 2.6 ACCESSORIES AND OUTLETS 56 2.7 INTERNAL LIGHTING 56 2.8 EMERGENCY LIGHTING 57 2.9 EXTERNAL LIGHTING 57 2.10 UNDERGROUND CABLES 57 2.11 EARTHING AND BONDING 59 2.12 LABELLING AND IDENTIFICATION 59 2.13 INTRUDER ALARM 59 2.14 METERING 59 2.15 TESTING AND COMPLETION 60 3.0 PARTICULAR SPECIFICATION 61 3.1 DISTRIBUTION BOARD/LVAC PANEL 61 3.2 CIRCUIT CONTAINMENT/WIRING 61 3.3 SMALL POWER 61 3.4 INTERNAL LIGHTING 62 3.5 EMERGENCY LIGHTING 63 3.6 EXTERNAL LIGHTING 63 3.7 SPARE LAMPS 64 3.8 HEATING 64 3.9 DEHUMIDIFIERS 65 3.10 SUMP PUMPS 66 3.11 INTRUDER ALARM SYSTEM 66 4.0 APPENDICES 67




1.0 GENERAL SPECIFICATION 1.1 Introduction

This document specifies the general electrical requirement for the building services installation within an 11kV (Primary Substation site) Switchouse and a 33kV (Grid Substation site) Switchouse. The extent of the works comprises of the supply, delivery, handling, installation, testing and commissioning of all equipment associated with building. All works carried out shall be undertaken by a contractor who is registered with the NICEIC and/or ECA to carry out the whole of the works as described in this document and set out on layout drawings. The electrical installation shall be installed and tested to BS 7671 IEE Wiring Regulations. Any operative working on the electrical installation in connection with the building services of the 11kV or 33kV Switchouses shall be qualified to a minimum standard of C&G 236, Part 2 and C&G 2381 or similar. The client reserves the right to check all operative’s qualifications prior to commencing any works on site. If the contractor has reason to believe that anything described in this document or shown on the layout drawings is inconsistent with his guarantee and responsibilities, he shall draw attention to such matters at the time of tendering. The words “complete installation” shall mean not only the major items of plant and equipment conveyed by this document, but all the incidental sundry components necessary for the complete execution of the works and for the proper operation of the installation. If any queries arise out of the specification of drawings, the contractor shall obtain the client representative decision before submitting his tender.

1.2 Scope The works shall allow for the complete heating and lighting electrical services installation. The scope of the work shall include the following, together with all other works necessary to provide a complete installation:




Distribution boards and associated equipment/cabling.

(a) Internal lighting scheme together with all lamps to all areas.

(b) Emergency lighting installation.

(c) General power distribution.

(d) Space and water heating installation including equipment.

(e) Dehumidification installation.

(f) External amenity lighting.

(g) Floodlighting to transformer bays.

(h) Earthing, bonding, testing and commissioning.

(j) Provision of installed drawings, manuals and test certificates.

1.2.1 Standardization and Generic Civil Design

Where possible the UK Power Networks generic design must be adopted on all civil design projects. Specific design considerations or risk assessments may determine alternate designs. The following Building Services specifications and drawings listed in the drawing list issued in conjunction with this document detail the preferred generic design for Grid and Primary Switchrooms to be adopted within the UK Power Networks network.




2.0 TECHNICAL SPECIFICATION 2.1. Final Distribution Boards and Equipment 2.1.2 All distribution boards shall be totally enclosed, metal clad, heavy gauge sheet steel,

arranged for conduit entry, 500 volts rating, to BS5490. All distribution boards shall have the facility for adding additional equipment (i.e. spare ways etc., typically 25%).

2.1.3 Distribution boards for three phase distribution shall be BS5486 Type B, of a pattern

able to house multi-pole MCB’s. MCB’s shall be selected as appropriate based on the load characteristics, i.e. battery charger Type D, lighting Type B, etc.

All distribution boards shall be positioned to allow adequate space for termination of

the incoming and outgoing cables etc. 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. Also provision shall be allowed for padlocking off individual MCB’s.

The enclosures for all switchgear and distribution boards shall be constructed in cast

metal and/or sheet steel (not less than 1.25mm thick). 2.2 Conduit Systems in General 2.2.1 Conduits shall be sized in accordance with the latest edition of BS 7671 with a

minimum size of 20mm diameter. 2.2.2 Conduit can be either PVC or galvanised steel. PVC is conduit is to be used in all

general applications; galvanised conduit is only be used in areas of impact high potential.

2.2.3 Use circular BESA boxes for drawing-in points, generally at two lengths of straight

conduit or after two 90o sets, but without prejudice to BS 7671. 2.2.4 Install completely and swab-through the whole conduit system before any wiring

commences. Do not pull cables round any box, burr or other source of abrasion. 2.2.5 Spacer bar type saddles shall generally be used throughout all installations. Finish

to match conduit.




2.2.6 Maximum distances between conduit fixings are to be as follows:-

Conduit size Steel PVC 20mm 1200mm 750mm 25mm 1200mm 750mm Over 25mm 1500mm 900mm

In addition, fix conduits at points 250mm either side of a bend or set and 300mm from a switch, outlet box or any other termination.

2.2.7 Where distance saddles are used, the conduit boxes must be of the raised back type to maintain an even spacing behind the conduit.

2.2.8 Use adaptable boxes 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 90o.

2.2.9 Adaptable boxes shall be to BS 4568, Part 2, minimum size 100 x 100 x 50mm.

Finish to match conduit. 2.2.10 Install surface conduit throughout in horizontal and vertical runs. Where several

conduits follow similar routes, group them into neat closely spaced runs. Do not form ‘U’ sets without an outlet.

2.3 Steel Conduit The following information applies to the specific use of galvanised conduit only for

use in high potential impact areas; 2.3.1 Steel conduit shall be heavy gauge screwed to BS 4568 part 1, either welded seam

or solid drawn, and manufactured by a member of the British Electrical Systems Association. The protective finish shall be either Class 2 – black stove enamelled or Class 4 – galvanised, as required elsewhere.

2.3.2 Earthing wires for conduit fittings shall be used throughout. 2.3.3 Conduit boxes shall be constructed of malleable iron with threaded entries or bush

entry looping boxes in accordance with BS 4568 part 2.




2.3.4 All accessories and fittings shall comply with BS 4568 part 2. The finish is to match the conduit.

2.3.5 Make bends and sets in a bending machine. Make good any damage to either the

enamelling or galvanising, together with all threads, with zinc phosphate primer as the work proceeds. Finish with galvanised or black enamel paint as appropriate.

The whole of each thread must be painted before screwing on a conduit box, coupler

or locknut. The installation is to be electrically and mechanically continuous throughout.

2.3.6 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. Bare thread shall be painted as stated elsewhere in this Specification.

2.3.7 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, shakeproof washer and brass smooth bore bush.

The correct size spanner or special tool shall be used to tighten smooth bore bushes.

2.4 Cable Trunking 2.4.1 Steel cable trunking shall be manufactured to BS 4678 Part 1 for surface trunking

and BS 4678 part 2 for underfloor trunking. The finish of the trunking in both cases is to be to class 3, painted or galvanised as required elsewhere.

2.4.2 All fittings are to be purpose made and generally of the ‘gusset’ type, unless stated

elsewhere. 2.4.3 Size the trunking in accordance with BS 7671 where sizes are not given elsewhere.




2.4.4 Where a trunking passes through a hole in the building structure, fix the cover plate

to the trunking before installation, arranged to project for 150mm each side of the hole.

2.4.5 Where any trunking passes through a fire wall, the integrity of the fire compartment

shall be maintained with suitable fire barriers. This shall be done both inside and outside the trunking.

2.4.6 Conductors of differing voltages may be installed in a common trunking, providing

full compliance with the segregation requirements of BS 7671 are maintained throughout.

2.5 Wiring Cables and Flexes 2.5.1 Colour(s) of cables shall be in accordance with BS 7671 to denote phases and

neutral. 3-phase circuits must be wired with different colour cables. 2.5.2 All cables shall be BASEC certified. 2.5.3 Cables of differing voltages and of varying electrical services shall be segregated

from each other in accordance with the requirements of BS7671 and all other Standards applicable to the services involved.

2.5.4 Minimum sizes of cables and flexible cords shall be as follows unless otherwise

detailed elsewhere: 2.5.5 Minimum conductor size for cables on lighting circuits 1.5mm2

Minimum conductor size for cables on power circuits 2.5 mm2 Minimum conductor size for flexible cords on lighting circuits 0.75mm2 Minimum conductor size for flexible cords on power circuits 1.5 mm2

2.5.6 Conduit wiring cables shall be either XLPE (90OC) insulated, non-sheathed stranded

copper cables 450/750V grade in accordance with BS 7211, as detailed elsewhere. 2.5.7 PVC insulated and sheathed single core cable shall be to BS6004, 300/500 volt

grade. Use double insulated No.618Y where no mechanical protection is afforded. 2.5.8 Flexible cables and cords shall be 85OC PVC insulated, 85OC PVC Sheathed, to

BS6141: 300/500V grade finished white unless otherwise specified elsewhere.




2.5.9 Cables shall be installed and fixed to manufacturers’ recommendations and in

accordance with the relevant sections and tables of BS7671. 2.5.10 Determine the number of cables to be drawn into each size of trunking and conduit

by reference to BS7671. 2.5.11 Leave sufficient slack at all cable terminations to permit 2 no future stripping and

reconnections to the terminal without causing undue stress in the cable. 2.6 Accessories and Outlets 2.6.1 All socket outlets are to be surface mounted double pole switched sockets and in

accordance with BS 1363:1995 unless otherwise stated elsewhere. 2.6.2 Surface mounted accessories and outlets shall be mounted on boxes from the same

manufacturer and range as the accessory or outlet.

Metal boxes shall be of the type without knockouts. Conduit entries shall be cut on site.

Moulded boxes are not to be used for conduit entry.

2.7 Internal Lighting 2.7.1 All luminaries shall incorporate 3 Amp fused terminal blocks for their mains

connection. The Contractor shall provide fused blocks to those luminaries that do not have them fitted as standard.

2.7.2 All switches shall be grid pattern with cover plates to match the power accessories.

Multi gang switches shall be used where appropriate and switches are to be mounted in a logical order.




2.8 Emergency Lighting 2.8.1 Emergency lighting system will be designed to meet BS 5266 Part 1 & 7: 1999 and so

achieve compliance with legislation. 2.8.2 The class of system is non-maintained 3 hours duration. 2.8.3 All emergency luminaries shall be connected so as to provide protection against

failure of the local circuit. 2.8.4 Above door emergency lights shall have exit legend plates over the luminaries. 2.8.5 In order to carry out periodic testing of the emergency lighting system, emergency

lighting key switches shall be installed. 2.9 External Lighting 2.9.1 Luminaires mounted on the external walls of a building shall be wired from inside

the building. The wiring method used shall be the same as for the internal lighting as stated elsewhere and controlled via an external photocell.

2.9.2 The transformer compound lighting shall be provided by 500w metal halide

floodlights mounted on 5m lighting galvanised steel raise and lower columns. Install sufficient columns to achieve a ground illumination level of 50Lux maintained illuminance with a uniformity factor of 0.5 across the compound. All luminaries to be controlled from a wall switch mounted inside the control room via suitably rated contactor. Final location will vary from site to site, client to confirm the final location.

2.10 Underground Cables 2.10.1 Cables laid underground shall be at a minimum depth of 450mm below finished

ground level. The cables shall be laid on a sand bed 75mm deep, free of stones, rubbish or decaying vegetation and unless otherwise stated covered with cable tiles complying with BS 2484, the hole shall then be covered with a further 75mm depth of sand. Under certain circumstances identification plastic tapes may be allowed in place of cable tiles at a minimum depth of 300mm. Also all Auxiliary cables are to be installed in ducts where practicable to afford maximum mechanical protection.




2.10.2 Unless otherwise stated, all underground cables shall be PVC sheathed/steel wire armoured.

2.10.3 All cable routes shall be agreed with the Client’s Representative before work

commences. 2.10.4 Care shall be taken not to damage the PVC sheath during installation. Cables

damaged during the installation shall be replaced upon instruction at no extra cost. 2.10.5 Where cables cross roads, footpaths etc., they shall do so via minimum size of

100mm diameter glazed earthenware ducts or PVC pipe or duct.




2.11 Earthing and Bonding 2.11.1 Bond all conduits, trunking, metal enclosures, the metallic sheaths of cables and

continuity wires of sheathed cables so as to be directly connected to the earth point. Earthing arrangements and the resistance of the protective conductors shall comply with BS7671.

2.11.2 Ensure that earth terminals are provided at all light points, switch positions, switch-

sockets and Connection Unit boxes. Earth wires within boxes shall be sheathed with green/yellow PVC sleeving.

2.12 Labelling and Identification 2.11.1 All labelling shall conform, where appropriate, to the requirements of BS7671 and

the following requirements. 2.11.2 Label all items of isolation and distribution equipment for ease of identification by

means of the specified and/or detailed engraved labels. 2.11.3 Clearly labelled “DANGER 400 VOLTS”, in red letters, each Switch/Fuse Isolator, Bus-

bar chamber and Distribution Board in which 3 phase 400 Volts is present. 2.13 Intruder Alarm 2.13.1 The intruder alarm system must be supplied, installed, testing and commissioned by

a specialist UK Power Networks approved contractors. 2.13.2 Intruder alarm multi-core cables shall be enclosed within a segregated cable

containment system. 2.13.3 Each entry/exit door to be protected by door contacts. 2.13.4 External bell box to be installed, location to be agreed with client representative. 2.14 Metering

2.14.1 In order to monitor Operational electricity usage within Substation sites it is required that a smart meter be installed.




2.15 Testing and Completion 2.14.1 Immediately upon completion of the electrical works complete, sign and date in

Installation Inspection Certificate. This shall be the ECA or NICEIC Certificate. The operative carrying out this work shall be qualified to C&G 2391 or equivalent.

2.14.2 All test results/readings shall be noted and attached on separate sheets. Each set of

test results shall clearly indicate the distribution board reference and the circuit tested.

2.14.3 The client reserves the right to witness all on-site testing and commissioning of the

electrical installation. 2.14.4 The contractor must be aware of the potential of possible high earth loop and PSC

readings equipment must be specified equipment accordingly.




3.0 PARTICULAR SPECIFICATION 3.1 Distribution Board/LVAC Panel The contractor shall allow for the design, supply and erection of a purpose built switch panel, which will house a 24 way TP&N distribution board c/w 125A TP&N integral disconnector, fuse switches and control devices for use in the 11kV (Primary) Switchouse and both 33kV (Grid) Switchouses. The above switch panel will be located within the auxiliary room and will supply all the low voltage equipment associated with the building services installation. The incoming LV mains supplies shall be supplied and installed by others, emanating from remote off-site LV transformers. Assume external loop impedance of supply at the LVAC panel will be no greater than 0.35 ohm for design purposes. Include for the installation of an earthing conductor connected from the LVAC switch panel main earth bar to the main earth tape installed within the basement, size to be determined at design stage. 3.2 Circuit Containment/Wiring All final/sub-circuits will be wired in 6491B (BS 7211) PVC single LS0H cables installed in galvanised steel trunking and conduit of a suitable size to maintain a spacing factor as the requirements of BS7671 including latest amendments. 3.3 Small Power 3.3.1 Install twin switched metal clad sockets wired on final ring circuits, protected by 30mA RCD units, with less than 40ms with a test current of 5 times In. 3.3.2 Socket Locations (exact positions can be agreed on site):

Socket fixes along perimeter walls of the switch room to suit equipment layout (minimum of 8 off). Final number to be confirmed by client representative.

Socket fixed along perimeter of auxiliary room to suit equipment layout (minimum of

3 off). Final number to be confirmed by client representative.




40A DP switch for 7kW instantaneous over sink water heater (Redring 7kW).

13A switched fused connection unit supplied for electric panel heaters and warm air

hand dryer.

Wall mounted extract fan powered from a local light circuit, switched by a integral PIR.

Mount all small power accessories at 1200mm from finished floor level.

3.4 Internal Lighting 3.4.1 All switches shall be grid pattern with cover plates to match the power accessories with all surface boxes without knockouts. Multi gang switches shall be used where appropriate mounted at 1400mm from floor level. 3.4.2 Switchroom internal lighting to comprise of wall mounted 2 x 58w 1500mm fluorescent fittings with sealed diffusers installed at 2250mm from floor level to the centre line of the fitting. Auxiliary Room internal lighting to comprise of ceiling mounted 2 x 58w 1500mm fluorescent fittings with sealed diffusers installed at 2700mm from floor level to the underside of the fitting. 3.4.3 Calculate at the tender stage the quantity of internal fittings required to achieve the following levels of illumination in accordance with HSG 38 Lighting at Work and CIBSE Code for Lighting:

In switch houses, 500 lux maintained luminance with a uniform factor of 0.8 across the front and rear elevation of all the switchgear, including spare bays.

In auxiliary rooms, 500 lux maintained luminance with a uniform factor of 0.8 across

the front and rear elevation of island panel suites and wall mounted equipment. In cable basement, 100 lux maintained luminance lux with a uniform factor of 0.7

across the entire floor area. 3.4.4 Luminary location of exact positions can be agreed on site with the client’s

representative.




Twin fluorescent fittings around the perimeter of the switch room at equidistant spacing. Provide single gang switch adjacent to outside doorway and doorway from relay room (two way working).

Twin fluorescent fittings on ceiling of the auxiliary room at equidistant spacing.

Provide single gang switch adjacent to outside doorway. 3.4.5 Basement lighting to switch house to comprise of twin 1500mm fluorescent fittings

c/w sealed diffusers positioned at equidistant spacing across the ceiling. Provide single gang watertight switch inside basement across door.

3.4.6 The relay panel interior lighting supply will be installed by others following building

completion.

3.5 Emergency Lighting 3.5.1 Provide non-maintenance emergency lights, with exit legends, above each exit door

from the switch house. 3.5.2 Periodic testing of the emergency lighting installation shall be carried out by key

switches mounted adjacent to general purpose light switch in the auxiliary room. 3.5.3 Emergency lighting shall consist of 3hr self contained non-maintained battery

conversion kits housed within general purpose luminaries and emergency exit signs. 3.5.4 Emergency luminaries shall conform to the latest recommendation; the design of the

luminaries shall have been tested and approved in accordance with the ICEL Scheme.

3.5.5 Emergency luminaries that are exit signs shall have legends, which conform to the

European Sign Directive Format. 3.6 External Lighting 3.6.1 The external lighting to comprise of wall mounted amenity style vandal resistant

bulkhead luminaries fitted with 28w 2D lamps. 3.6.2 The required number and mounting height of the external luminaries is that every

exit door (including basement door) has a fitting above the external landing mounted




just above the transom level of the door. Exact positions can be agreed on site with the client representative.

3.6.3 The wall lights shall be wired in PVC singles contained in conduit fed back entry into

the light fittings. 3.6.4 External building lighting to be switched via an external photocell which will switch

on at dusk and then off at midnight. 3.6.5 Provide internal switch within auxiliary room for manual control of all external lights,

when required. 3.6.6 The transformer external compound lighting consists of 2 number 500w “TH”

floodlight per transformer mounted on 5m high-galvanised steel lighting columns complete with raise and lower mechanism. Where transformers are enclosed the floodlights can be installed on surrounding building structures in agreement with the client’s representative. This will remove maintenance access requirements for columns although lights fixed to building structures must be at least 3.5 meters from all live parts of the adjacent transformer.

3.6.7 In accordance with CIBSE Code for Lighting the level of lighting in transformer bays

will need to be increased to 300 lux maintained illuminance. This can be achieved by the use of temporary lights during periods where work is to be carried out. The lights are to be positioned to suit the work being carried out.

3.6.8 Designated XLPE/SWA cable routed through cable ducts supplied from LVAC power

housed in the auxiliary room. 3.6.9 The transformer compound lighting shall be switched via designated ‘floodlighting’

contactor and manual one gang one switch incorporating within the LVAC panel. 3.7 Spare Lamps 3.7.1 Provide spare lamps of each type installed within the completed building. Supply a

quantity of two lamps of each type installed except for 1500mm fluorescent, five spare tubes are required.

3.8 Heating 3.8.1 All switchouse heaters to be in accordance with BS EN 60335-2-30:2003.




3.8.2 Heating to be provided by wall mounted panel convector heaters rated at minimum 2

kW. The heating is background only with an occupancy boast required from a central controller.

3.8.3 Install wall mounted heaters in Auxiliary room (final position to be agreed) controlled

by a central electronic programmable thermostat located in the Switchroom and connected to common heating circuit via dedicated switched fused connection unit.

3.8.4 Install wall mounted heaters in Switchroom (positions to be agreed) controlled by

central electronic programmable thermostat and connected to common heating circuit by dedicated switched fused connection units.

3.8.5 The thermostat controlling the heaters shall be set at 5°C and locked off against

tampering. An override switch with a 4 hour maximum timer shall be fitted to allow an increase in ambient temperature to 21°C during occupation.

3.9 Dehumidifiers 3.9.1 The switch hall requires the installation of two permanently fixed dehumidifiers to

maintain the relative humidity within the space to below 60%. 3.9.2 The contractor shall install and connect dehumidifiers generally as indicated on the

layout drawings and in accordance with the appropriate manufacturer’s Operation & Maintenance Manual.

3.9.3 The units are to be mounted at approximately 200mm above floor level, final

positioning shall be agreed on site prior to installation. 3.9.4 Include for drain pipes routed directly through the wall into the rainwater gulley.

Each drain is to be installed complete with trace heating cable, which shall be installed in accordance with the manufacturer’s instructions. The contractor shall take care when installed the units to ensure that the condensate drains are 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.

3.9.5 Each dehumidifier incorporates a set of humidity alarm contacts. The Contractor

shall wire 2 x 1.5mm2 single cores within separate conduit/trunking from each unit to an adaptable box at the mains position. Final connection to the alarm panel will be by others.




3.9.6 Provide a dedicated radial circuit to each dehumidifier complete with switched fused

connection unit mounted adjacent to dehumidifiers. 3.10 Sump Pumps 3.10.1 If required the contractor shall allow for the supply, installation and commissioning

of two single phase submersible pumps at each end of the basement. The pumps will draw water from the grated sumps and discharge through the basement wall into the rainwater gulley at each end of the building. Details on the exact installation requirements for the pumps and associated controls to be agreed on site.

3.10.2 Provide a high level watertight connection unit at each end of the basement for the

supply to the pumps to be installed below. Each sump pump control unit to have a dedicated radial circuit back to the distribution board.

3.11 Intruder Alarm System 3.11.1 The contractor shall employ the services of specialist UK Power Networks current

approved Security contractor to supply, install and commission the intruder Alarm system for the switch house utilising equipment approved for use and compatible with current UK Power Networks Company Security standards.

3.11.2 The Alarm repeat keypad shall be mounted as indicated on the layout drawing and

be capable of accepting a designated security number. 3.11.3 Perimeter protection shall be provided within the substation with the use of door

contacts only (PIR’s are not to be used). 3.11.4 The Alarm control panel shall be fitted with a repeat auxiliary relay facility with a pair

of volt free contacts (normally open) that will close upon alarm initiation and that will carry 10mA dc.

3.11.5 The contractor shall supply and install and terminate a 4 core cable between the

Intruder Alarm panel auxiliary relay and a third party remote call centre, if required. 3.11.6 The contractor shall install all necessary power supplies, location to be agreed with

specialist contractor.




4.0 APPENDICES 4.1 Schedule of Equipment Type Distribution Equipment MEM, Dorman Smith Merlin Gerin or similar approved

Surface metalclad type B, 125A rating c/w integral isolator housed within LVAC panel

Accessories MK, MEM, Crabtree or similar approved

Surface Metalclad on boxes without knockouts. Light Switches – Grid Pattern. Surface Metalclad Sockets – Twin Switched Connection Units – Switch Fused.

Dehumidifiers Ebac or similar approved

Nominal airflow 90m3/hr desiccant dehumidifier with air cooled condenser with wall installation kit and pump drain, c/w wall mounted humidstat (RH15) or similar approved.

Heaters and Controls All Heaters:- PLX/NC wall mounted convector panel heater with no in-built control except safety cut-out. Rating 2.0 kW.

Switchroom Control:- PX010eCentral control unit / thermostat – configures for comfort boost of 21°C for 4 hours (repeatable) and setback to 5°C when unoccupied.

Provide 63A heating contactor with enclosure between controller and heater circuit in switch hall.




Schedule of Luminaires

AREA/TYPE

MODEL/RANGE LAMP TYPE

Internal ‘A & AE’

Surface mounted, high impact resistance, fluorescent luminaire and proof diffuser to IP65 AE as above c/w maintained 3 hr emergency battery pack

2 x 1600mm 58w T8: 3500K

A1 & A1E Surface mounted, high impact resistance, fluorescent luminaire and proof diffuser to IP65 AE as above c/w maintained 3 hr emergency battery pack

1 x 1500mm 58W T8 : 3500k

B Surface mounted compact luminaire c/w HF control gear and optical diffuser

28W, 2D 4 PIN

External

Vandal resistant, corrosion resistant wall mounted luminaire c/w control gear

70W SON

Transformer Compound

250w Metal Halide Luminaire mounted on 5m steel column to suit application i.e. raise and lower mechanism.

1 x 500w 240v, CAP R7

Emergency E & E1

Self contained luminaire with 3 hr non-maintained operation to IP65. E1 fitted with escape legend to current building regulations requirements.

1 x 300mm 8w, T16

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