ELECTRICAL ENGINEERING SERVICES SPECIFICATION

Transcription

1 ELECTRICAL ENGINEERING SERVICES SPECIFICATION Standard Material & Workmanship Clauses WESTWOOD PRIMARY SCHOOL Maple Grove, March Cambridgeshire, PE15 8JT May 2017 Issue Date : May /1

2 INDEX 1 CONTENTS ELECTRICAL SERVICES Introduction... 3 General Design... 3 Engineering Philosophy ELECTRICAL ENGINEERING SERVICES... 8 SECTION 2: STANDARD MATERIAL & WORKMANSHIP CLAUSES LIGHTING LEVELS IN SCHOOL AREAS ADDENDUM STANDARD SYMBOLS & NOTATIONS FOR ELECTRICAL ENGINEERING SERVICES Issue Date : May /2

3 ELECTRICAL SERVICES 2 INTRODUCTION General The building services shall be designed to: Provide all materials and works in accordance with the current Building Regulations, Building Bulletins, British Standards and Codes of Practice. Ensure all equipment and systems are designed and installed in accordance with the relevant standards and that operational compatibility exists between the systems and any other system installed at the same location. Supply plant and equipment to achieve the specified design conditions and to provide stable control. Comply with the requirements of the local Building Control office. Allow easy access for maintenance of the equipment. Minimise health and safety risks to maintenance operatives and others. 3 DESIGN Engineering Philosophy The engineering services design approach shall focus on a number of key design goals. These have been identified and summarised below (although are not limited to). These design goals shall be used during the design development in order to provide a building that can: Meet the current and future functional needs of the building and its occupants Offer a high quality internal environment Considers the school s teaching needs Be safe and secure Be flexible in its usage and operation Respond to future change (e.g. teaching, operational, layout and technological change etc.) Make creative and maximum use of natural light Minimise energy usage Maximise use of passive environmental control (daylight, natural ventilation, good thermal insulation etc.) Minimise maintenance requirements and costs Offer value for money Issue Date : May /3

4 The design of the engineering services will be in accordance with the client brief and associated technical design guidance notes (e.g. DFES Building Bulletins). Issue Date : May /4

5 1.1.1 Incoming LV Service The existing incoming low voltage electrical supply to the school is provided by UK Power Networks. The threephase and neutral (TPN) service head and supplier s metering equipment are located in the existing main electrical switch-room, adjacent to the stage. The existing main electrical supply cable to the school is in poor condition, with its insulation deteriorating, and needs to be replaced and the electrical service to the school needs to be upgraded to support the anticipated additional electrical load required. The existing maximum demand of the school has been recorded on the supplier s bills as being 67kVA, against the available service capacity of 75kVA, over the peak months October to March. Preliminary calculations indicate the additional maximum demand on the electrical load of the building as a result of this project will be approximately 35-50kVA, i.e. the load additional to the existing maximum demand. This additional load does not allow for any further spare capacity to accommodate future expansion of the school beyond that envisaged by this project and additional capacity will be required on the incoming LV electrical service to such future expansion. An upgraded LV supply is required and new incoming electrical service cable will be derived from the local Regional Electricity Company s LV network and will be a 3-phase, 4-wire, 400V/230Vac and provided by an underground cable LV Distribution The existing main electrical LV distribution switchgear to the school is located in the main electrical intake-room, adjacent to the stage. LV distribution around the site is currently provided by moulded case circuit breaker (MCCB) distribution panels. There are insufficient spare ways on the existing MCCB panels for the new circuits required. Therefore, a new TPN MCCB distribution panel will be required for new sub-main distribution. New distribution boards will be provided for final circuit distribution to new extension areas and the upgraded kitchen. Due to the proposed layout some existing circuits to areas outside of project scope will require extending to new distribution board positions and some circuits will need to be reconnected to the existing board. New MCB distribution boards will be surface mounted, with steel casings and hinged lockable covers. All new distribution boards shall come complete with their own integral isolator, integral electric meter and will be installed in new extension corridor area to provide reasonable, quick and adequate access for maintenance, inspection and testing purposes.. New distribution boards shall be provided with a spare capacity of 20-25% for future additional circuits. To comply with Part L Building Regulations all distribution boards shall be metered to monitor lighting and small power usage. Ideally with two separate integral meters in one distribution board for separate metering of lighting and small power usage. All outgoing supplies from the MCCB panel will be metered either integrally to the distribution board or within the MCCB panel. All meters will be digital using standard pulse outputs to connect to any future building management system. All final circuits will be installed with MCB s and residual current devices via single-pole RCBOs Small Power General power is to be provided throughout the new areas of the building to meet the need for small power in each of the proposed teaching areas. Socket outlets and accessories are to be provided for ICT use, general purpose use, cleaning purposes, specialist equipment and machinery (if any). Electrical accessories are to be installed flush, in conduit, DADO trunking, surface mounted or incorporated into fixed furniture dependant on client requirements. Accessories within general teaching areas are to be white plastic pattern type finish. Issue Date : May /5

6 Emergency power off buttons are to be provided to the kitchen. Provision is to be made for the installation of interactive whiteboards in teaching areas, to include sockets, switched at low level, for the installation of a projection unit. Power supplies are to be provided for miscellaneous mechanical equipment, hand dryers in toilet areas, urinal systemiser flush units and any other fixed electrical appliances required. In areas of refurbishment the existing small power installation is to be modified or replaced with new to suit the proposed layouts. The number of socket outlets and dedicated power supplies to be provided in each area are indicated by the room data sheets Lighting Change of use and layout requires that new lighting installations are to be provided in all areas of the refurbishment. Lighting is to be provided to the new and refurbished areas of school by energy efficient LED panels (600mm x 600mm) to fit seamlessly into the new ceiling grid. As LED lighting produces high current jump during switching consideration should be given during design stage to the number of panels installed on each circuit, to avoid nuisance tripping as lights are switched. The new LED lamp sources are to generally be of a colour temperature of 4000 K from colour rendering range. LEDs in general teaching areas will be compliant to CIBSE Code of Lighting Part 2 and Building Bulletin 90. All new lighting is to be controlled by an absence detection lighting control system and photocell daylight sensors are to be included such that lighting remains off when there is sufficient natural light to achieve the design illumination levels, which are indicated by the room data sheets Emergency Lighting Emergency lighting is to be provided to required areas of school to comply with BS: Generally non-maintained emergency lighting is to be provided by battery packs fitted integrally to general lighting luminaires and non-maintained, self contained, miniature luminaires utilising white high efficiency 3W LED lamps. The emergency lighting luminaires are to operate in event of power failure to relevant lighting circuit and batteries are to provide power to emergency lamps for a minimum duration of three hours.. Emergency lighting is to incorporate self-testing fittings. Within school buildings, the emergency lighting system will provide a minimum of 1 lux at floor level for the following: - escape routes, including changes of direction and external exits from the building - fire-fighting equipment points - fire alarm call points - directional or other emergency signage - any generally unoccupied area without natural daylight, including plant and switch rooms - Toilets exceeding 8sqm. Issue Date : May /6

7 1.1.6 External Lighting External lighting will be provided to standards specified by CIBSE Lighting Guide to illuminate the new building entrance canopy, extended building perimeter and any areas where illumination may be required for security and safety. New external lighting will be provided by wall mounted LED lamp sources, controlled by photocell daylight sensor units to prevent external lighting from operating during daylight. The sensors will in turn be controlled by a seven-day programmable time clock with an integral override switch Data and Telecommunications New data points are to be provided throughout the new areas as indicated by the room data sheets. It is anticipated that new data cabinet(s) will be required to serve the extension and refurbished areas, which are to be linked to existing network via a new fibre optic cable. The existing telephone system will be extended throughout the new areas to serve telephony to be provided as indicated by the room data sheets Fire Alarm System The existing fire alarm system installed to the school is an analogue addressable system and is to be extended to serve the new and remodelled areas of the building. The extension of the existing system requires that the number of fire zones will increase and a new fire alarm panel is required to accommodate a minimum of 8 fire zones. All existing circuits, some of which may need to be expanded, are to be reconnected to the new panel. The new installation shall conform to British Standard BS5839 Part 1, P2/L2 standard. Additions to the fire alarm system will consist of manual call points to all new exits from the building, automatic smoke and heat detection devices, electronic sounders and visual indicators. Interface units are to be provided to control mechanical plant, door retaining devices, gas valves as required. Automatic fire detection is to generally be provided by combined optical/heat type detectors to suit the differing types of area. Visual alarms (beacons) are to be provided to toilet areas and any other areas where the hearing impaired may be alone Security The existing site wide intruder detection system (IDS) is controlled by a control panel located in the reception office within existing building. The IDS is to be extended throughout the new and remodelled areas of the building. Social areas, kitchen areas and exit routes are to be zoned to allow the IDS to be controlled at different settings in different areas to suit the requirements of the school s activities. The existing keypad, located in the school reception area, and all existing system devices are to be retained except in areas of demolition, where devices are to be disconnected from system prior to demolition works commencing. New intruder alarm devices, connected to the existing system, are to be provided as necessary to protect all points of access to the new building and other high risk areas within the new building (to be agreed with the school). Issue Date : May /7

8 New system devices are to consist of expansion panels, keypads for zones to be set/unset, proximity detectors of the dual technology type, door contacts and internal alarm sounders. Alarms will generally operate as a sequentially confirmed alarm by operation of two or more alarm devices to conform to BS EN The existing CCTV system is to be upgraded and extended with new cameras are to be installed into extension areas, including additional cameras to cover areas of potential bullying or conflict (to be agreed with the school). 4 ELECTRICAL ENGINEERING SERVICES SECTION 2: STANDARD MATERIAL & WORKMANSHIP CLAUSES 2.01 GENERAL The Electrical Engineering Services Standard Material & Workmanship Clauses shall be applicable to all electrical engineering works, unless otherwise stated in the Particular Specification, or on the drawings. It shall be read in conjunction with any preliminary clauses, any Particular Specification and/or drawings applicable to the works. Where discrepancies arise between these documents the order of precedence shall be as follows: Drawings. Particular Specification. Standard Material & Workmanship Clauses. The symbols used on drawings shall be in accordance with those appended to this specification COMPLIANCE WITH REGULATIONS & CODES OF PRACTICE The works shall be carried out in accordance with all relevant statutory requirements, the current edition of BS 7671: Requirements for Electrical Installations (complete with Amendments and Guidance Notes), the requirements of the Regional Electricity Company, British Standard Codes of Practice, Approved Documents of the Building Regulations and recognised trade association and professional institution practices. BS 7671 shall henceforth be referred to as the Wiring Regulations. All regulations, standards etc., referred to shall be deemed to incorporate all current amendments and guidance notes in force. Where applicable, the recommendations of the Building Services Research and Information Association (BSRIA) shall be complied with. Where an interpretation or a recommendation concerning any of these requirements has been published by the National Inspection Council for Electrical Installation Contracting (NICEIC) this shall be taken as the definitive version MATERIALS & WORKMANSHIP All materials used shall be new and unused, and shall both before installation and on completion, be free from rust, scale, deformation or discolouration and be of the type and manufacture specified. They shall conform to the requirements of any appropriate British Standard Specification and be CE marked. All materials shall be selected to withstand the external influences they will be subjected to, be compatible with their surroundings and be capable of being maintained. No materials generally known to be deleterious shall be used. Any materials which show deterioration due to neglect in storage or installation will not be accepted. Issue Date : May /8

9 The specific instructions of original equipment manufacturers shall be adhered to in every respect. Workmanship shall conform to the standard of first class engineering practice. Equipment shall be erected plumb and true with fixings capable of sustaining a minimum weight of 40kg or three times the weight of the item, whichever is the greater. No item shall rely on one fixing only. The work area shall be kept clean and tidy with all rubbish etc. removed upon completion of the task TENDER DOCUMENTATION The contract documents shall be deemed to include those drawings and specifications on which the contract for the works is based. Drawings may include Sketch Drawings, Schematic Drawings or Detailed Design Drawings. The determination of unspecified parameters may form part of the works. This could include the production of Co-ordination Drawings and Schedules where these are not included as part of the Tender Documentation or stated as to be produced during the Production Information Stage. The Particulars of Contract shall state whether the Construction (Design and Management) Regulations (CDM) apply in full. In such instances the Planning Supervisor's pre-contract Health and Safety plan will accompany the tender documents. Where a tender summary and schedule of rates are included in the Particular Specification these shall be completed fully and submitted with the tender to be used for pricing any variations, additions, omissions etc., 2.05 INSTALLATION DRAWINGS & BUILDERS WORK DETAILS Installation Drawings, Shop Drawings, and Builders Work Details shall be produced by the Contractor as required for the construction of the works, and/or if called for in the Particular Specification. These shall be submitted for examination prior to any installation and/or manufacture taking place. Two sets of drawings shall be required showing details of plant rooms, general arrangements of the installation, wiring diagrams for control circuits, layouts of panels etc., 2.06 HANDOVER INFORMATION Record Drawings Prior to Practical Completion a complete set of drawings showing the installation as installed shall be provided. They shall beforehand be submitted for comment for suitability of purpose (but not accuracy) and shall include all of the requirements detailed in BSRIA Technical Note 15/95. The drawings shall initially be prints for inclusion in the O & M Manual (inserted into clear PVC envelopes). Subsequently a set of CAD Drawings to BS EN ISO 7519: 1997 on disc shall be submitted within four weeks of Practical Completion Operating and Maintenance (O&M) Manuals Two copies of an Operating & Maintenance Manual shall be provided 14 days prior to Practical Completion as part of the works. It shall include all the information necessary to provide for the safe and efficient operation and maintenance of the engineering services which comprise these works. The manual shall meet the requirements of the following: BS EN BS 4940 AG1/87.1 BSRIA TN15/95 Specification for Technical Manuals Recommendations for the presentation of Technical Information etc. Applications Guide. Operating and Maintenance Manuals for Building Services Installations. Technical Note. Handover Information for Building Services. Issue Date : May /9

10 Health and Safety at Work Act 1974 (HSWA) Construction (Design and Management) Regulations 2007 (CDM) Control of Substances Hazardous to Health Regulations 2002 (COSHH) Any other relevant legislation. Manuals shall be either Class B or Class D as described in BSRIA AG1/87.1. The appropriate type of manual shall be specified in the Particular Specification or on the drawings. Where not so specified the manual shall be Class B. Class B manuals shall generally comprise: Record drawings and drawing symbols. Manufacturer's operating and maintenance instructions. Test and commissioning certificates. Warranties. Equipment inventories with manufacturers names and addresses. A Class B manual may be prepared by the Contractor. Class D manuals shall comprise the contents detailed in BSRIA TN 15/95, which shall generally be as follows: Record drawings, symbols, charts and schedules How to use the manual Emergency information Contractual and legal information Systems description and design intent Asset list/equipment schedule Parts identification and recommended spares Spares policy Commissioning data Operation Maintenance recommendations and records to date Fault finding Lubrication Modification information Disposal instructions Names and addresses of manufacturers Index of plans and drawings Manufacturer's literature A Class D manual shall be prepared by a specialist author as recommended by BSRIA or as approved by the Contract Administrator. Both classes of O & M manual shall clearly describe isolation procedures, and appropriate locations shall be marked on the record drawings. Copies of the distribution schedules shall be included within each class of manual. Manuals shall comprise loose-leaf A4 pages on good quality paper suitable for heavy usage, inserted in four-ring PVC covered hardback binders having stepped overlapping card dividers between sections. An information sheet shall be provided in the front of the manual listing the names and addresses of the installation, the author, the consulting engineer (KIER Services) & the installation Contractor. Manual details and the relevant information shall be provided on the front cover and the spine. The client shall have sole copyright. Practical Completion may be withheld until the O & M manual has been substantially provided Maintenance All systems shall be properly maintained in accordance with the manufacturer's requirements, and relevant British Standards etc., and trade practices to the date of Practical Completion (unless ongoing maintenance comprises part of the specified works). As part of the O & M manual, comprehensive maintenance recommendations and records of maintenance to date shall be provided. From the date of Issue Date : May /10

11 Practical Completion the client will assume the responsibility for maintenance (unless maintenance is part of the works). Where the O & M manual, record drawing or any other relevant maintenance information is not handed over prior to Practical Completion, the Contractor shall be responsible for the cost of maintenance and the consequences of a lack of proper maintenance during the period between Practical Completion and approval of the relevant documents, as detailed in BSRIA TN 15/ Health & Safety File The O & M manual inclusive of all record drawings shall comprise an integral part of the Health and Safety file as defined by the Construction (Design and Management) Regulations (CDM) irrespective of whether these regulations apply in full to the works. Where the CDM Regulations apply in full to the works, the CDM Co-ordinator shall approve the Health and Safety File and may not approve Practical Completion until such time as a suitable file is prepared Log Books Fire Alarm, Emergency Lighting and Lightning Protection systems where forming part of the works, shall be provided complete with a log book as detailed in the appropriate British Standard. Where any other system is supplied with a log book then this shall be provided. Log books shall accompany (but not form part of) the O&M Manual, and instructions on their use shall be contained in the O&M Manual DEMONSTRATION & INSTRUCTION At Practical Completion the building occupier shall have the whole of the works described and demonstrated to them. This shall include instruction in the use of all plant, operation of all equipment, systems, controls, isolation and minor maintenance procedures, etc., all as is necessary to enable the systems to be fully understood and correctly operated. It should be noted that the Instruction cannot properly take place until the Operation and Maintenance Manual has been provided and that the said Instruction is subject to those Health and Safety Implications detailed for O & M Manuals VISITS TO SITE Where the work involves the alteration, extension or modification of an existing installation in an existing building, the Contractor is advised to visit the site prior to submitting a tender in order to ascertain the full extent of the work. No claims for additional work, which should have been identified by a site visit, will be considered ASBESTOS OR OTHER SUBSTANCES HAZARDOUS TO HEALTH IN EXISTING BUILDINGS The Contract Administrator shall inform the Contractor where asbestos or other substances which are hazardous to health are known to exist. The Contractor shall inspect the premises' Health and Safety File for records of asbestos or other substances prior to commencing the works. The employer may have records additional to those in the Health and Safety File. Where the Health and Safety File is not present or in the opinion of the Contractor is not complete, the Contractor shall request additional records from the employer, and such records shall not unreasonably be withheld. Attention is drawn to the fact that works may be required in the vicinity of asbestos of one form or another. The Contractor will be required to inspect the Property Asbestos Log Book (for buildings where they exist) prior to carrying out any works on existing buildings, and must sign in the appropriate column to confirm he has done this. He will be required to follow the procedures set out in the Log Book. If the Log Book indicates that the area of works will disturb asbestos, the Contractor must inform the Contract Administrator and await instructions. If asbestos is specifically mentioned in the Particular Specification, then the specified instructions shall be executed. Where during the course of the works, asbestos or other substances are found, which in the opinion of the Contractor are hazardous to health, any work which involves the disturbance of such a substance shall be immediately stopped. If working within a ceiling void or duct, close the access covers, or if working in a boiler or plant room, close the door and put up a notice "NO ENTRY". Inform the Contract Administrator immediately and await further instructions. Issue Date : May /11

12 If an accident occurs whereby asbestos or other substances are inadvertently disturbed in no circumstances attempt to sweep up or dispose of it but report to the Contract Administrator after complying with the above requirements ELECTRICITY SUPPLY & METERING EQUIPMENT Where the provision of an electricity supply cable from the UK Power Networks is required, this shall be separately detailed elsewhere. The application for the provision of metering equipment (other than for a Contractor s temporary supply) shall be carried out by the Client. The prospective short circuit current and the external earth loop impedance shall be stated in the Particular Specification where known EARTHING ARRANGEMENTS Unless otherwise detailed the provision of an earthing terminal will be by the Regional Electricity Company, and connected to a Protective Multiple Earthed (PME) network. The earthing arrangements shall comprise the TN-C-S/TN-S system, & protection against indirect contact shall be by earthed equipotential bonding & automatic disconnection of supply unless an alternative system is detailed. Circuit protective conductors (CPC) shall comprise those contained within (or the sheath of) composite cables unless otherwise detailed. Where separate or supplementary protective conductors are required these will be detailed in the particular documents. Where required by the Wiring Regulations main equipotential bonding conductors shall be installed connecting the main earthing terminal to extraneous conductive parts. These parts include gas, water or any other service or part that may be specified in the Particular Specification or on the drawings. Where main equipotential bonding conductors are connected to a main earthing terminal they shall be fitted with a label designating their function. Equipotential bonding conductors shall be connected to localised extraneous conductive parts. Such parts shall be deemed to include the peripheral grids of suspended ceilings. Local supplementary bonding connections shall be installed where required by the Wiring Regulations, and additionally between exposed conductive parts having a resistance in excess of 0.05 ohm MOUNTING HEIGHTS Equipment shall be mounted at the following heights above finished floor level (AFL) to the centre of the item unless otherwise detailed in the particular documents. ITEM LOCATION HEIGHT (mm) Lighting Switches 200mm to any adjacent door 1100 Socket Outlets Generally 450 Socket Outlets Above working plane 150 over working plane TV Points Generally 450 Telephone Points Generally 450 Telephone Points Wall Telephone 1400 Fire Alarm Contacts 1100 Fire Alarm Bells 2200 Thermostats 1500 Control Devices & Switchgear Indicators Where items of equipment are to be installed immediately adjacent to each other, but detailed to be at different mounting heights as indicated in the above table, then the Contract Administrator shall be consulted to facilitate an aesthetic solution Switches, outlets & controls (Extract from Building regulations Part-M) Design considerations The key factors that affect the use of switches, outlets and controls are ease of operation, visibility, height and freedom from obstruction. However, there will be exceptions to height requirements for some outlets, e.g. those set into the floor in open plan offices. Issue Date : May /12

13 2.14 A consistent relationship with doorways and corners will further reinforce the ease with which people manipulate switches and controls All users should be able to locate a control, know which setting it is on and use it without inadvertently changing its setting Controls that contrast visually with their surroundings are more convenient for visually impaired people, as are light switches that are activated by a large push pad. The colours red and green should not be used in combination as indicators of on and off for switches and controls. It may be useful to use text or a pictogram to clarify the purpose and status of multiple switches & controls It is also an advantage if individual switches on panels and on multiple socket outlets are well separated, or in the form of large touch plates, to avoid the inadvertent selection of an adjacent control by visually impaired people and people with limited dexterity. Provisions 2.18 Switches, outlets and controls will satisfy Requirement M1 if: a. wall-mounted socket outlets, telephone points and TV sockets are located between 400mm and 1000mm above the floor, with a preference for the lower end of the range; b. switches for permanently wired appliances are located between 400mm & 1200mm above the floor, unless needed at a higher level for particular appliances; c. all switches and controls that require precise hand movements are located between 750mm and 1200mm above the floor; d. simple push button controls that require limited dexterity are not more than 1200mm above the floor; e. pull cords for emergency alarm systems are coloured red, located as close to a wall as possible and have two red 50mm diameter bangles, one set at 100mm and the other set between 800mm and 1000mm above the floor; Issue Date : May /13

14 f. controls that need close vision are located between 1200mm & 1400mm above the floor so that readings may be taken by a person sitting or standing (with thermostats at the top of the range); g. socket outlets are located consistently in relation to doorways and room corners, but in any case no nearer than 350mm from room corners; h. light switches for use by the general public have large push pads and align horizontally with door handles within the range 900 to 1100mm, for ease of location when entering a room; i. where switches described in 4.30(h) cannot be provided, lighting pull cords are set between 900mm & 1100mm above floor level, & fitted with a 50mm diameter bangle visually contrasting with its background & distinguishable visually from any emergency assistance pull cord; j the operation of switches, outlets & controls does not require the simultaneous use of both hands, except where this mode of operation is necessary for safety reasons; k. switched socket outlets indicate whether they are on ; l. mains and circuit isolator switches clearly indicate that they are on or off; m. front plates contrast visually with their backgrounds IDENTIFICATION LABELS & NOTICES Each item of switchgear (including MCCBs), control gear, distribution equipment and joints shall be labelled or engraved unless there is no possible confusion over its purpose. Where specialist labelling or engraving is required this will be detailed in the particular documents. Unless otherwise detailed labels shall be traffolyte with black lettering on a white ground, of a size appropriate and proportional to their application. Labels shall generally be screw fixed unless adhesive fixing is agreed with the Contract Administrator. Every item of equipment or enclosure within which 400V exists shall have a black on yellow label (to BS 5378) label reading "DANGER volts". Where separate enclosures (within 2m of each other) house terminations having 400V between them, each item shall have a black on yellow label affixed internally reading "DANGER volts between adjacent equipment". Each distribution board shall have its protective devices sequentially numbered. Single phase boards shall be numbered commencing at 1. Three phase boards shall be numbered using the notation 1/L1, 1/L2, 1/L3, 2/L1, 2/L2 etc. Distribution equipment shall be equipped with a typewritten distribution schedule installed within a clear PVC pocket fitted to the inside of the hinged lid. Where there is insufficient space inside the equipment, or where there is no hinged lid, then the schedule shall be mounted within a glazed frame screw fixed adjacent to the equipment. The schedule shall identify the utilisation, area served, current rating, and size of conductors for each protective device. (Note that copies of these schedules are required for the O&M Manuals). At the origin of very installation a periodic inspection and test notice as prescribed in the Wiring Regulations shall be affixed. Note shall be taken that it may not be deemed safe to authorise Practical Completion without the proper identification notices and labels MAIN SWITCHGEAR Issue Date : May /14

15 Main switchgear shall generally comprise either HRC fusegear or moulded case circuit breaker panels mounted directly on to brick or block walls, and interconnected with steel cable trunking. All switchgear shall be complete with locking-off facilities to enable secure isolation. An installation drawing of the switchgear shall be submitted to the Contract Administrator, or alternatively the equipment shall be laid out on site for approval before erection commences. A suitable chart giving instructions for dealing with electric shock shall be installed adjacent to each switchboard. The chart shall be a waterproof type as provided by Electrical Review, the British Safety Council or similar DISTRIBUTION BOARDS Distribution boards shall be installed at heights agreed on site, and connected to suitable steel cable trunking to house outgoing cables. The distribution boards shall be fitted with the rating and types of protective devices detailed, blank covers or fuse bridges for spare ways, adequate earthing terminals, hinged lids and locking off facilities. Where RCBOs or RCDs are specified these shall be 30mA unless otherwise detailed. 1 dolly locking device shall be provided with each MCB distribution board. Distribution schedules shall be fitted as previously detailed CABLES Generally The types of cables to be installed shall be detailed in the particular documents. Cables shall not be installed under tension, they shall be installed parallel or at right angles to walls and floors, under no circumstances shall diagonal runs be permitted. The fixing centres, bending radii and identification of conductors shall accord with the Wiring Regulations. Proprietary fixing clips shall be used. Cables with reduced neutrals shall not be installed unless detailed elsewhere. Cables shall not be installed when the ambient temperature is below 0 o C. Joints shall not be permitted unless by prior agreement with the Contract Administrator. Unless otherwise stated the minimum size of cable used shall be 1.5mm 2 In all cases cables shall have BASEC approval, unless an approval system is not in force for the particular cable type. Cables and their enclosures passing through fire barriers (i.e. Walls and floors) shall be internally and externally sealed against the propagation of fire. Small holes shall be sealed with a PVE foam aerosol, larger holes and trunking etc. shall be sealed with proprietary intumescent blanket material Electromagnetic Compatibility (EMC) Low voltage cable installations shall not cause damage, interference or malfunctions of other systems. To reduce electromagnetic interference (EMI), mains voltage and signal cables following parallel routes shall have minimum separation as detailed in the following table unless otherwise specified. MINIMUM SEPARATIONS IN mm FOR ALL TYPES OF INTERFERENCE SIGNAL CABLES (RECEPTOR) Twin & Earth MAINS VOLTAGE CABLES (SOURCE) Earthed Earthed Steel Wire Conduit Trunking Armoured MICC Twin PVC Sheathed Unscreened Twisted Pair Screened Twisted Pair Aluminium Foil Screened Issue Date : May /15

16 Steel Wire Armoured MICC Coaxial Acknowledgement is made to the ECA for the use of the above table. Unless specifically stated single core cables shall not be installed (with the one exception of short 'tails' at meter connections). Lighting circuits shall employ 2 and 3 core cables using the '3 plate' method. Where single and 3 phase circuits installed in conduit or trunking comprise separate unsheathed cables, the cables for each separate circuit shall be taped together to minimise EMI. Where screened cable is specified, unless otherwise detailed, its screen shall be earthed at the supply end only and insulated at the remote end Underground Cables Underground cables or ducts shall be installed at a minimum depth of 450mm, on a bed, and with a cover, of sifted soil or sand. A continuous length of proprietary yellow marker tape labelled "CAUTION ELECTRIC CABLE BELOW" shall be installed over the complete length of the cable at 400mm below ground level. Where ducts are specified they shall be from the 'Rigiduct' range of twin walled, high density polyethylene ducting, as manufactured by B&H (Leics) Limited. Underground ducting shall be in accordance with the National Colour Coding System for buried services as follows: Colour Black Red Blue Yellow Grey/White Green Service LV Electricity HV Electricity Water Gas Communication and Alarms Cable and Closed Circuit Television Where underground cables surface they shall be in an area where damage is unlikely, or they shall be enclosed in conduit, or covered with capping for a height of 1.8m. Cable ducts terminating in a building shall be sealed to prevent entry of vermin etc. As an alternative to excavation, and where specified, ducts may be installed by the thrust-boring technique. In this case the ducts shall have the words "DANGER ELECTRICITY CABLE" printed on them. Underground cables shall be installed segregated by a minimum horizontal distance of 400mm from other services. Where cables cross other services they shall be installed within ducts. Where supplementary protective conductors are specified they shall be installed immediately BELOW the main cable. Reinstatement shall be equal to the existing surrounds and shall include re-tarmacing or re-turfing Multicore Armoured Cables Unless otherwise detailed these cables shall comprise:- 1. PVC insulation, Single Wire Armour and PVC sheath (PVC/SWA/LS0H) to BS for conductors up to 10mm 2 2. Thermosetting insulation (XLPE), Single Wire Armour and LS0H sheath to BS 5467, for conductors of 16mm 2 and above or 3. XLPE insulated, Single Wire Armoured, Low Smoke and Zero Halogen (LS0H) sheathed to BS 6724 and 4. Conductors shall be copper (cu) unless aluminium (al) is specified. The cables shall be 600/1000V grade, with the armouring used for earthing purposes unless otherwise detailed. The termination of the armouring shall generally be by a mechanical cable gland to BS 6121, a proprietary earth tag washer (fixed with brass nut and bolt), and a PVC or LS0H shroud. Issue Date : May /16

17 The gland shall be either dry indoor, weatherproof or flameproof as required for the environment. If armoured cables are recessed into wet plastered walls termination shall be made without using a cable gland, the armouring being terminated directly onto an earth terminal. Alternatively an additional cable core shall be used for the protective conductor. In non-industrial interiors where groups of wiring cables enter distribution boards in cable trunking, the armoured cables shall take the same route. The armour shall be terminated with an earthing clamp to BS 951, and connected to an equivalent size copper tail. Terminations for copper conductors connecting to stud terminals shall be with crimped lug terminations. Terminations for aluminium conductors shall be crimped, lug type for stud terminals, and pin type for tunnel terminals, or alternatively aluminium to copper tail connectors shall be used. The 'swaging' method of termination shall NOT be used. All crimping shall be with proprietary crimping tools and dies. The treatment of aluminium conductors and armouring shall be as follows. Mating surfaces shall be cleaned bright with wire wool then coated with a proprietary jointing compound. This shall be carried out immediately prior to crimping to prevent surface oxidisation Mineral Insulated Cables Mineral Insulated cables (MI) shall be to BS They shall have copper conductors and sheath, be light or heavy duty, with or without PVC or LS0H oversheath as specified. Fittings shall be to BS Cables shall be installed exactly in accordance with the manufacturer s instructions using proprietary tools. The cable shall generally be terminated using an earth tail seal and gland. Where termination boxes will not accept a male gland and locknut, a female pattern gland and male bush shall be used (steel conduit couplers shall not be permitted). Where proprietary MICC cable wiring accessories are specified, glands shall not be installed, and earth tail pots are not essential. For flameproof applications cables shall be heavy duty and BASEEFA approved flameproof glands and 'increased safety' seals shall be used. Cable cores shall have identification ferrules affixed PVC Insulated & Sheathed (Non-Armoured) Cables Unless otherwise detailed these cables shall comprise: 1. Flat 2 or 3 core cables with circuit protective conductor to BS 6004 Table 5. (6242Y or 6243Y). 2. Flat 2 core cables (with or without CPC) 1.5 or 2.5 mm 2 with stranded conductors to BS 6004 Table 6. (6242Y) 3. Single core, flat 2 or 3 core cables without CPC to BS 6004 Table 4. (6181Y, 6192Y or 6193Y). 4. Circular twin, 3 or 4 core cables to BS 6004 Table 3 (6182Y, 6183Y or 6184Y). 5. Circular twin, 3 or 4 core cables with CPC and heavy duty sheath (e.g. 'Hituf'). All cables shall be 300/500V grade with copper conductors. Unless otherwise stated all cables shall be multicore and complete with an integral circuit protective conductor. Single core cables shall NOT be in general use. Due to EMI problems, they shall be restricted to short lengths used for interconnecting switchgear and metering equipment. These cables shall not be installed surface clipped unless otherwise detailed. They shall be installed within cavities of ceilings, floors and partitions (but not in the cavities of external walls). Where cables drop from the ceiling (or rise form the floor) to wall mounted points, or are cast into concrete, they shall be completely enclosed within conduit or trunking. The conduit (or trunking) may be surface or recessed as specified in the particular document, and shall comply with the respective standard clauses. For cables installed in accordance with these methods glands/clamps are not generally required Fire Resistant Silicone Rubber Insulated Aluminium Foil & LS0H Sheathed Cable complete with CPC Fire Resistant Cables shall comply with BS 6387 and BS 7629, and have a BASEC Certificate of Approval. They shall be multicore cables having copper conductors. Issue Date : May /17

18 The methods of installation shall be exactly in accordance with the requirements for non-armoured PVC insulated and sheathed cables. For the prevention of mutual detrimental influence these cables shall be regarded (i.e. segregated) in accordance with the requirements for mineral insulated cables, for EMC separation the table in this specification is applicable. Cables shall be installed exactly in accordance with the manufacturer s requirements. For terminations where space is limited, such as a circular conduit box, the conduit box shall be fitted with an extension ring sufficiently deep to avoid the cores being forced against the box. Cable glands shall be installed in all cases other than where cables are enclosed within conduit or trunking. Where the cable is reliant on its clipping to retain its integrity in the event of a fire, fire resisting (i.e. metallic) clips shall be used Special Cables for Extra-Low Voltage Applications These cables shall include telecommunication, bell, call, sound distribution, data transmission, alarm, radio and television cables. The cable shall be as specified in the Particular Specification. The methods of installation shall be exactly in accordance with the requirements for non-armoured PVC insulated and sheathed cables, unless otherwise detailed. In some cases these cables will be installed by others (e.g. British Telecom). Conduits provided for these cables shall be left with a draw wire installed Single Core PVC & LS0H Insulated Cables These cables shall be 300/500V grade, have solid or stranded copper conductors and be in accordance with BS 6004 Table 1(a), (6491X and 6491B). They shall be installed completely enclosed within conduit and/or trunking which shall comply with the relevant sections of this specification. The type of conduit or trunking shall be specified in the Particular Specification. All wiring systems comprising single core PVC insulated cables shall have a separate circuit protective conductor installed unless otherwise specified. The size of the CPC shall be specified within the particular documents, and installed irrespective of the type of conduit systems. If not so specified the CPC shall comply with table 54G of the Wiring Regulations. The spacing factor shall be in accordance with the Wiring Regulations CONDUIT, CABLE TRUNKING & CABLE TRAY SYSTEMS Generally The types of conduit or cable trunking to be installed shall be detailed in the particular documents, installed surface or recessed as specified. Conduit and trunking shall be installed vertical or horizontal and parallel to walls. Diagonal runs may be permitted in floors, ceilings and in some special circumstances such as a cooker final connection, subject to the approval of the Contract Administrator and where steel conduit is used. Recessed conduit shall not be installed in walls less than 100mm thick without prior instructions from the Contract Administrator. The fixing centres for conduits and cable trunking shall not exceed HALF the distances tabulated in the Wiring Regulations. Each conduit/accessory box shall be fixed independently of the conduit system. Bending radii of conduit shall be not less than the values stipulated in the Wiring Regulations. Conduit and trunking systems shall be either continuous, for the installation of unsheathed cables, or isolated sections for the protection and enclosure of sheathed or armoured cables. In both instances metallic conduit/trunking shall be bonded to the earthing terminal, but shall not in itself be used as a protective conductor, a separate CPC shall be installed. This requirement shall not apply to isolated lengths of conduit used as communication and data wireways etc. The use of inspection pattern conduit fittings shall not be permitted, all fittings shall comprise circular, square or rectangular boxes. Where groups of cables enter distribution boards, or to alleviate multiple conduit runs, trunking shall be installed, steel or PVC, to be compatible with the wiring system in use. Where surface conduit or trunking is installed, all the installation components shall be suitable for the type of wiring, including the provision of surface patresses where these are required Circular Steel Conduit Steel conduit shall be of metric dimensions to BS The sizes used shall be 20, 25 and 32mm. Steel conduit shall be heavy gauge welded, generally finished stove enamelled black (Class 2). Issue Date : May /18

19 For external applications, within boiler rooms, ducts and other damp situations, conduit shall be hot dipped galvanised (Class 4). For flameproof applications solid drawn conduit shall be installed. All conduit accessories shall match the type of conduit used. Where steel conduit is installed surface mounted, screwed accessories shall be used, any exposed thread lengths shall be treated with a compatible paint. Where steel conduit is recessed, 'pinch-grip' accessories may be used. Fixing of surface steel conduit shall be with distance saddles, and recessed conduit with pipe hooks (crampets). No other methods shall be used unless with the prior consent of the Contract Administrator. The terminations of steel conduit into enclosures and boxes not fitted with spouts shall be with a coupler & male bush Circular PVC Conduit PVC conduit shall be to BS 4607 and BS The size used shall be 20mm and 25mm, and the conduit shall be of the super high impact heavy gauge grade. The colour shall generally be white, unless black is specified, and all accessories shall match the conduit. The fixing of surface PVC conduit shall generally be by spacer bar saddles, recessed conduit shall be secured with pipe hooks (crampets), and connections made with proprietary solvent cement. Where bends are required proprietary bending springs shall be used. In straight runs exceeding 6m an expansion coupling shall be installed Steel Cable Trunking Steel cable trunking shall be to BS 4678 where applicable. It may comprise square, rectangular, floor, skirting or bench trunking as specified. It shall generally comprise standard gauge finished stove enamelled dark grey, but for installations within boiler rooms and other damp situations trunking shall be hot dip galvanised pattern. For each change of direction, and at every joint or 'T', the trunking manufacturers accessories shall be used unless by prior arrangement with the Contract Administrator. Unless otherwise detailed bends and 'T's shall be radius pattern, and any reducers bellmouth pattern PVC or GRP Trunking PVC cable trunking shall be to BS 4678 where applicable. It may comprise square, rectangular, mini, cornice, architrave, dado, skirting, floor or bench trunking as specified. The finish shall generally be white. For each change of direction and at each joint or 'T' the respective trunking manufacturer s accessories shall be installed. Where situations require butt or mitre joints the prior approval of the Contract Administrator shall be obtained PVC Screeded Floor Ducting This shall be as specified complete with the manufacturer s proprietary accessories and installed exactly in accordance with the manufacturers requirements. Each length of trunking shall be covered with an overlapping (100mm each side) expanded metal mesh prior to screeding. This metal mesh shall be earthed to an adjacent service box by a fixed earth terminal (brass nut and bolt), and a similar nut and bolt fixed through the metal mesh. The precise location of outlets shall be confirmed with the Contract Administrator prior to screeding Cable Tray or Basket Unless detailed otherwise, internal cable tray shall be heavy duty return flange pattern of 1.5mm gauge minimum. It shall be hot dip galvanised steel to BS 729, and installed complete with the manufacturer s accessories. Cable basket shall be installed complete with the manufacturer s accessories and installed exactly in accordance with the manufacturer s requirements Cable Ladder This shall be alloy or GRP as specified, complete with the manufacturer s accessories and installed exactly in accordance with manufacturers requirements FLEXIBLE TERMINATIONS Flexible terminations shall be as detailed in the Particular Specification and shall generally be one of the following methods. Issue Date : May /19