FA007 Stand Electrical

8/6/2019 FA007 Stand Electrical

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File: FA007; Addenbrookes NHS TrustStandards for Contractorselectricalg/users/northfir/standards for contractors/electrical / March 2004this document is subject to monitoring and review and thus will be updated on a regular basis

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ADDENBROOKE'S NHS TRUSTESTATES & FACILITIES MANAGEMENT

"Committed to Providing a Safe and Effective High QualityEnvironment for the Delivery of Healthcare"

ESTATES DOCUMENT

"STANDARDS FOR CONTRACTORS"

ELECTRICAL


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TABLE OF CONTENTS SITE RULES

Paragraph Page

1. GENERAL 32. SEQUENCE OF WORKS 33. MECHANICAL WORKS 34. BUILDERS WORKS 35. SEGREGATION OF SERVICES 36. CONDUIT AND FITTINGS 47. ADAPTABLE BOXES 48. STEEL TRUNKING 59. CABLES IN CONDUIT AND TRUNKING 510. TERMINATION OF CABLE CONDUCTORS 611. PVC CONDUITS 6

12. PVC CONDUIT RUNS 613. PVC CONDUIT JOINTS 714. PVC ELBOWS AND TEES 715. SUSPENSION OF HOT OR FULLY ENCLOSED LUMINAIRES 716. MECHANICAL CONTINUITY AND EARTHING 717. PVC DRAW IN BOXES 818. WIRING OF PVC CONDUITS 819. PVC TRUNKINGS 820. FLEXIBLE CABLES AND CORDS 921. PVC INSULATED AND ARMOURED CABLE 922. CABLE TRENCHES 1123. MINERAL INSULATED METAL SHEATHED CABLE 11

24. CABLE TRAYS 1225. LV SWITCHBOARD PANELS AND DISTRIBUTION FUSEBOARDS 1226. UNIT TYPE SWITCHBOARDS 1327. CUBICLE TYPE SWITCHBOARDS 1328. SWITCHBOARD CONNECTIONS AND TERMINATION OF CABLES 1329. DISTRIBUTION FUSEBOARDS 1430. LABELLING 1431. WIRING ACCESSORIES 1432. EARTHING GENERALLY 1533. AS FITTED DRAWINGS AND MAINTENAANCE MANUALS 1534. GUIDANCE FOR WORK WITH ASBESTOS INSULATION BOARD 1635. TESTING 16


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Electrical

1. General

This section includes standard clauses covering wiring systems and all PVC cables,LV switchboards and panels, distribution fuseboards, lamps, lighting switches,socket outlets, clocks, earthing and testing.

It shall be read in conjunction with the Contract Specification, NHS ModelEngineering Specification, current IEE or ICE wiring guidance, relevant HTMs inparticular HTM 2007 and with any drawings and schedules issued as part of acontract package.

The following sections define the minimum standard of installation that will beconsidered acceptable by Addenbrookes NHS Trust. Different i.e. higherstandards, may apply on a project specific basis and if required, they will befound in the electrical section of project specification.

2. Sequence of works

Except where a particular sequence of operation is specified, the work shall becarried out whole or in sections as the conditions or state of the building maydictate, or at the direction of the Supervising Officer.

The contractor shall carry out all of the required works to an agreed programmewith the Supervising Officer and within the contract period stated on the contractdocuments.

Quotations and tenders are to be based on the assumption that some work may

be required to be carried out outside normal working hours to facilitate thenormal running of the hospital and allowances for this must be made whensubmitting your return.

3. Mechanical works

All mechanical works associated with the electrical services shall be carried out bythe main contractor in accordance with the mechanical section of this document.

The electrical contractor shall supply the main contractor with duplicate copies of dimensioned mechanical work drawings, indicating all holes, supports, trenchesetc.

4. Builders works

All builders works associated with the electrical services shall be carried out bythe main contractor in accordance with the building section of this document.

The electrical contractor shall, supply the main contractor with duplicate copies of dimensioned builders work drawings, indicating all holes, supports, trenches etc.

5. Segregation of services

5.1 Conduit systems, conduits & cable trays

Independent conduit systems or separate compartments of a multi-


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compartment trunking system or separate cable trays shall be used for thefollowing items: Mains voltage lighting and power cables; Radio, alarm and call systems cables; Telephones/Telecommunication cables; Intercommunication systems cables; Patient monitoring cables; Fire alarm cables; and Data Transmission/Network cables, except where otherwise

specified .

5.2 Installation of Cabling

All cabling will be clipped at suitable intervals as dictated in Appendix 1 of this document.

5.3 Fire Stopping

All holes created through existing fire barriers whilst installing cable trays,trunking, etc. must be made good by the main contractor and fire stoppedby an approved fire barrier specialist.

5.4 Fixings (General)

All electrical equipment unless otherwise specified will be securely fitted tothe building fabric using rawl bolts, sleeve anchors or woodscrews andrawplugs. Where equipment is to be fitted to existing steelwork, theSupervising Officer's approval is required before any work commences.

6. Conduit and fittings

6.1 Conduit and Conduit fittings shall be:

6.1.1 To the requirements of Section C41, NHS Model EngineeringSpecification.

6.1.2 Of heavy galvanised weather proof type where installed externally,with mineral jelly between surface of joints or alternatively fittedwith proprietary gaskets.

6.1.3 Of heavy duty black enamel type where installed internally.

6.1.4 PVC conduit may only be used where specifically authorised.

7. Adaptable boxes

7.1 Adaptable boxes shall be:


7.1.2 Fitted with overlapping lids where used on flush installations.


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7.1.3 Heavily galvanised and firmly secured to the fabric of the building.

8. Steel Trunking

8.1 Steel trunking shall be:


8.1.2 Used where shown on the drawings or as called for in the particularspecification, where multiple conduits runs would otherwise occuror in approved positions as directed by the Supervising Officer.

8.1.3 Manufactured in the following gauges:

8.1.4 Up to 50mm x 50mm (2" x 2") or equivalent cross sectional area,

1.25mm U (18 swg).

8.1.5 Above 50mm x 50mm (2" x 2") and up to 100mm x 100mm (4" x4") or equivalent cross sectional area, 1.6mm U (16 swg).

8.1.6 Above 100mm x 100mm (4" x 4") or equivalent cross sectionalarea, 2mm U (14 swg).

8.1.7 Fitted with drip proof close fitting covers securely fixed to thetrunking by an approved means that will avoid damage to thecables.

8.1.8 Fitted with manufacturer's standard radiused or angled bends ortees as required.

8.1.9 Fitted with segregating bridging pieces at take off points to ensureseparation of services at all tee connections.

9. Cables in conduit and trunking

9.1 Cables shall be:

9.1.1 To the requirements of Section C41, NHS Model Engineering

Specification.9.1.2 Provided with copper conductors with LSOH insulation to 600/1000

volt grade, and shall be PVC insulated. Cables having insulation of XLPE, EPR rubber or silicone rubber or other heat resistant cablesshall be used in the positions and areas as indicated on thedrawings or as called for in this specification.

9.1.3 Coloured in accordance with the current edition of the IEERegulations. Coloured sleeves shall only be used with the writtenapproval of the Supervising Officer.

9.1.4 Installed without joints. Live conductors of lighting circuits shall betaken direct to switches; neutral conductors shall be looped at


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lighting points.

9.1.5 Segregated in accordance with the current edition of the IEERegulations and with the requirements of the particularspecification.

9.1.6 Fitted with shake-proof or spring washers on all bolted connections.

9.1.7 Of stranded or single core construction in the case of 2.5mm 2

cables as detailed in the specification.

9.1.8 No conductor used shall be smaller than 1.5mm 2 .

9.1.9 Only single cables are permitted, no multi core cables such as Twin and Earth are permitted unless specifically authorised.

10. Termination of cable conductors

10.1 Conductors shall be:


10.1.2 Terminated by one of the following methods unless otherwisestated.(a) Sweated lugs of the appropriate size of the cable used.(b) Compression type lugs.(c) Pinch screw type terminals that do not spread conductors.(d) Clamp type terminals.

10.1.3 Doubled back on themselves for all single connections of conductorsize up to and including 2.5mm 2 .

11. PVC Conduits

11.1 Shall be to the requirements of Section C41, NHS Model EngineeringSpecification. PVC conduit and accessories shall be coloured white unlessstated otherwise, and shall be installed so as to conform precisely to anyinstruction, recommendations or details given or suggested by the conduitmanufacturer.

11.2 All conduit boxes shall be white PVC, have steel insert clips, with coversfixed with brass screws, and of approved manufacture. Where PVCconduits are run on the surface or in ducts and creepways, they shall besecurely fixed by PVC distance saddles spaced not more than 725mmapart. Spacer bar saddles must not be used without prior authority inwriting by the Supervising Officer. Saddles shall be rigidly secured with50mm x No 8 BJRH screws in plastic rawlplugs.

11.3 Saddles shall be fixed at each change of direction and all boxes carryinglight fittings, switches, sockets and other accessories shall be rigidly andsecurely fixed independently of saddles. All other conduit boxes must besecurely fixed before cables are drawn in.


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12. PVC Conduit Runs

12.1 Conduit wherever possible shall be run in the roof space/ceiling void or, inscreed, or sunk below plaster depth when in walls. Full use shall be madeof any existing trenches, ducts or creepways provided for other services.

12.2 Conduit shall be run in such a manner so as to be perfectly smooth insideand out, free from any imperfection of any kind. When two or moreconduits run parallel with each other, the distance between them shall notbe more than 12.5mm and where such conduits run cross, use shall bemade of 150mm x 100mm x 40mm adaptable boxes. Not more than 3 x20mm conduits shall enter the smaller side of these boxes. Wheneverconduits are run it will be the responsibility of the contractor to firstascertain whether any other services, e.g. water, steam, gas or heating,affect the conduit run.

12.3 Any work along with any materials that are required to reduce or eliminatethe effect of such services or associated conditions including any highambient temperatures must be included by the contractor in his tender.

13 PVC Conduit Joints

13.1 Where PVC conduits are to be installed they must have their ends cutperfectly square and be deburred. After jointing, all adhesive must becare fully removed.

13.2 PVC conduit boxes having wherever possible, spout entries, shall be usedat the termination of all conduits, all lighting points and draw in boxes onconduit runs.

13.3 For 20mm conduits, round boxes shall be used at the draw-in points.

13.4 For 25mm or larger conduits, rectangular boxes shall be used. Wherespout entries are not possible conduits shall be finished off with machinedcouplings, and smooth bore bushes.

14. PVC Elbows and Tees

14.1 No tees or elbows except for tee and elbow boxes used as specified aboveshall be used in the installation, all bends and sets shall be made with abending machine using formers and springs of the correct size or asdirected by the conduit manufacturer. All bends shall be set in the conduitwithout indentation; the bore being full and free from burrs throughout.

15. Suspension of hot or fully enclosed luminaries

15.1 Conduits used to suspend hot or fully enclosed light fittings shall be heatresistant (at least to ANTS Certificate 78/2 Standard).


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16. Mechanical continuity and earthing in PVC conduits and trunkings

16.1 The whole of the PVC conduit system shall be mechanically continuousthroughout.

16.2 The contractor shall supply, install and connect separate earth continuityconductors to all final sub-circuits, which shall:-

16.3 Be installed in identical manner as other circuit conductors (radial or ring)Take the same route as other circuit conductorsHave a stranded cross sectional area equal to the largest circuit conductor,and not less than 1.0mm 2 (7/0.67).

17. PVC Draw in boxes

17.1 Sufficient draw-in boxes shall be installed to permit the re-wiring of theinstallation and to ensure this, no box shall be installed in an accessibleposition. The contractor shall minimise the use of draw-in boxes in roomsand corridors and shall check all proposed positions with the SupervisingOfficer before their installation, in the case of flush draw in boxes theelectrical contractor shall fit a break joint ring to cover joint betweenplaster and box.

17.2 Only draw tapes manufactured by the conduit manufacturer from nylonmaterials are to be used. The use of steel draw tapes is strictly prohibited.

18. Wiring of PVC conduits

18.1 Before any cables are installed, the conduit installation and the erection of fuseboards shall be completed and inspected by the Supervising Officer orhis appointed representative. Any conduit rejected by the SupervisingOfficer shall be changed at the contractors own expense.

18.2 A swab shall be drawn through each length of conduit to clean the interiorand remove any moisture or surplus adhesive and all boxes shall becleaned out.

18.3 All cables except where otherwise stated in this specification shall bethreaded into the conduit without undue tension or crossing. Themaximum number of cables bunched in any one conduit shall not exceedthat laid down in the current edition of the IEE Regulations. From time totime the electrical contractor will be required to withdraw cables containedin certain conduits at sundry selected points, to demonstrate that theserequirements have been recognised.

18.4 In the event of any protective insulation being damaged whilst cables arebeing threaded into conduit the whole of the particular length concernedmust be replaced and refixed by the contractor at his own expense.


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19. PVC Trunkings

19.1 Shall be to the requirements of Section C41, NHS Model EngineeringSpecification.

19.2 PVC trunking and fitting shall be super high impact heavy gauge, heavyduty, all insulated, clip-on lid, PVC trunking and accessories. Any non-standard trunking fittings shall be fabricated by the manufacturers.

19.3 Where moulded PVC accessory boxes are used in conjunction withminiature PVC trunking, these must accept the trunking into the mouldedbox by at least 5mm, and if it is required to remove any knockouts or anypart of the accessory, this shall be done such that the trunking forms atight fit into the accessory. Both trunking and accessory shall be free fromany kind of burr. Any accessory that is considered by the SupervisingOfficer or his representative not to be satisfactorily mounted or joined tothe trunking, shall be removed and replaced entirely at the contractor'sown expense.

19.4 All cable trunking shall be run neatly and fixed in contact with thehorizontal and vertical corners of the building, with switch drops run incontact with the vertical side of the door architrave. The completeinstallation shall be as inconspicuous as possible. Where changes of direction occur only approved pattern manufactured bends tees or blankends shall be used.

19.5 Conduit branch-offs shall be made with suitable clearance in the walls of the trunking and male PVC bushes fixed direct into couplings on the end of the outgoing conduit.

19.6 Trunking shall be rigidly fixed by round head wood screws and plastic wallplugs spaced no more than 600mm apart. In damp situations the trunkingshall be spaced off the wall by 20mm spacing collars.

19.7 Fire alarm wiring shall not be installed in the cable trunking.

19.8 Care shall be taken to ensure that the number and size of cables in anysection of trunking, does not exceed the 'Space Factor' stipulated in thecurrent edition of the IEE Regulations.

19.9 Due allowance shall be made for the expansion of PVC trunking at themaximum rate of 6.5mm per 3.5m run, and in this respect holes for fixing

screws shall be slotted.19.10 Joints in PVC trunking shall only be made using the internal, external or

flange couplings recommended by the manufacturer.

19.11 The termination or changes of direction in PVC trunking will be made usingthe preformed accessories recommended by the manufacturer.

20. Flexible cables and cords

20.1 Flexible cables and cords shall be:


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20.1.1 To the requirements of Section C41, NHS Model Engineering Specification.

20.1.2 Be PVC insulated and sheathed where used for pendant lighting fittings,adjustable lamps for other portable appliances, unless otherwise specified.

20.1.3Be of the heat resistant type of silicone rubber and glassfibre braided forthe final connections to all tungsten lighting fittings with a loading of 150 watts ormore.

Be LSOH [Low Smoke Zero Halogen]

21. PVC Insulated and armoured cabled

21.1 PVC/SWA cables shall be:


21.1.2 Be of the 600/1000 volt grade unless otherwise specified.

21.1.3 Any deviation shall be approved by the Supervising Officer before layingcommences. The routes shall be measured by the sub contractor on site, and heshall be responsible for ensuring that the correct lengths are ordered. Any lengthfound to be measured too short shall be replaced with cable of the correct length.

21.1.4 Be delivered to the site in one continuous length on a drum ready for

laying. No "through" or "T" joints shall be made unless called for in the particularspecification or shown on the drawings.

21.1.5 Supported as necessary to meet the requirements of the IEE Regulations.Terminated in suitable compression glands of the type which provide ananchorage and a cross-joint bonding of the armouring. The glands shall then befitted with PVC shrouds, which completely encase them.

21.1.6 Straight through joint and tee joint boxes shall be to the requirements of Section C41, NHS Model Engineering Specification.

Be LSOH [Low Smoke Zero Halogen]

21.2 PVC insulated wire armoured cable shall be installed:

21.2.1 In such a manner that the cable and the cleats do not come into contactwith gas, oil, steam, hot and cold water or any other service.

21.2.2 In ducts and on the walls of buildings using silicone aluminium claw typecleat supports or glass fibre, nylon reinforced hooks and clamps as indicated onthe drawings or as called for in the specification.

21.2.3 On walls using cleats of the correct size and type to suit the overalldiameter of the cable fixed to unistrut bracketry. The cleats or other specifiedsupports shall be installed in accordance with the current edition of the IEE


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Regulations as regards radius of bends and to manufacturer's recommendationsas to spacing between supports, and in a manner that no undue strain is put onthe cables or the sealing gland.

21.2.4 With fire resisting infill where passing through floors or walls, to complywith the current edition of the IEE Regulations. (See Building Section, para 33).

21.2.5 Protected from mechanical damage to height of 2m (6') above floor level,where run on the surface of walls.

21.2.6 All cable routes shall be clearly marked on the 'As Fitted' drawings (to besupplied as DXF files) with adequate dimensions from fixed building lines tofacilitate subsequent identification of the cable route.

21.2.7 To present a neat installation on walls and terminated with purpose madeglands and armour clamps.

21.2.8 In ceiling voids or on soffits on heavy gauge galvanised cable tray on

ladder rack fixed at regular intervals not exceeding 1200mm fixed with fault ratedcable clips or cleats.

22. Cable Trenches

22.1 Shall be to the requirements of Section C41, NHS Model EngineeringSpecification.

22.2 The sub-contractor shall be responsible for clearly marking out all cableroutes on site. The excavation, back filling and reinstatement of theground will be carried out by the main contractor at no cost to the sub-

contractor.

22.3 No cable trenches shall be back filled without the prior approval of theSupervising Officer. Any work carried out on instructions given wrongly bythe contractor shall be charged to the contractor including the cost of making good.

22.4 The position of the cables shall be indicated where entering buildings by aplate fitted to the wall, engraved with the size and voltage of the cable.Engraving details will be given by the Supervising Officer during the courseof the contract.

23. Mineral Insulated Metal Sheathed Cable (MIMS)

23.1 Mineral insulated metal sheathed cable shall be:


23.1.2 Of conductor sizes complying with the appropriate rating tables of thecurrent edition of the IEE Regulations, except that no conductor of less than1.5mm 2 shall be used.

23.1.3 Single and multiple clamp type glands which are an integral part of switchboxes will not be accepted, unless specifically agreed with the Supervising Officer.


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23.1.4 Fitted with flameproof seals when fitted to flameproof equipment.

23.1.5 Fixed by means of copper saddles to match the sheath of the cable.Saddles shall be fixed to walls, ceiling etc, by means of purpose made plugs andscrews as detailed for conduit work. Saddles shall be spaced as given below:

Maximum Spacing of FixingsOverall Diameter of CableVertical Horizontal

Up to 9mm 225mm 400mmAbove 9mm to 15mm 300mm 600mmAbove 15mm to 20mm 800mm 1000mm

23.2 Where several cables are run together, multiple saddles shall be used

23.3 Tested by the contractor in the presence of the Supervising Officer or hisrepresentative not less than 24 hours after installation and completion of seals. Any cables not giving an infinity reading when tested with a 500volt Megger shall be resealed by the contractor at his own expense.

23.4 Tested before and immediately after covering by concrete, plaster or beingburied in the ground for conductivity and insulation resistance to verifythat no mechanical damage has occurred.

23.5 PVC sheathed where installed on the surface in damp or humid conditionsand where buried in the ground, plaster or floor screeds, with PVC hoodsand shrouds provided.

23.6 Terminated in suitable adaptable boxes which shall be complete withterminal blocks so that not more than 3 x 2 core or 6 x 1 core cables areterminated at any one light point. The terminal block shall be labelled toindicate the circuit details.

23.7 Installed using galvanised boxes in damp or humid conditions. At lightfitting, socket outlet or switch positions, jointed by connections into theterminals provided. Where switch or loop in terminals are not provided

jointing shall be made by pinch screw or flat clamp type connectors.

23.8 Installed by tradesmen who have had a course of instruction in thehandling and jointing of MIMS cables.

23.9 Installed in accordance with the current edition of the IEE Regulations.

24. Cable Trays

24.1 Cable trays shall be:


24.1.2 Perforated steel of not less than 0.9mm up to 100mm width, 1.25mm upto 150mm or 1.6mm up to 300mm, and shall be PVC dipped in all cases where

MIMS cables are used and galvanised, zinc coated or PVC dipped for other


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applications.

24.1.3 Adequately sized to support the cables without bunching; and

24.1.4 Shall utilize manufacturers fittings or equivalent.

25. LV Switchboard Panels and Distribution Fuseboards

25.1 All switchgear on switchboards shall be:

General

25.1.2 Metal clad, totally enclosed and rated at 500 volts. Unit or cubicle type asindicated on drawings or specification.

25.1.2 Of the current rating, number of poles and fusing arrangements as

indicated on the drawing and specification.

25.1.3 Fitted with HRC fuses, MCBs or MCCBs as indicated. The neutral shall besolidly earthed at the transformer or at the MV switchpanel if this is locatedimmediately adjacent to the transformer.

25.1.4 Made so that cable entry plates on non-demountable units and cubiclesshall be readily removable to facilitate the making of holes etc.

26. Unit Type Switchboards

26.1 Unit type switchboards shall be:

26.1.1 Constructed of fuse switches or switchfuses as specified, mounted on anangle iron framework of dimensions indicated on the drawings, or constructedfrom other proprietary type of framework of rigid construction and free fromvibration due to operation of the switchgear. The framework shall be filed cleanat intersections before assembly to ensure good contact and securely fixed inplace by masonry bolts or similar.

26.1.2 Fitted with bus-bar chamber which shall extend the full length of theswitch frame. The bus bars shall be colour coded with phases at each coverplate.

26.1.3 Complete with earth continuity conductor, earthing all components asspecified in the current edition of the IEE Regulations.

26.1.4 Supplied with solid copper or aluminium connections between bus barsand switches, with clamps and bolts, for connection above 60 amps. PVCinsulated cables shall be used for other interconnections. Colour identification of phases by tape or sleeving.

26.1.5 The same manufacturer for any one contract.

27. Cubicle Type Switchboards

27.1 Cubicle type switchboards shall be:


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27.1.1 Manufactured from sheet steel, rust proofed or electroplated, not less than2mm thick, adequately braced. Drawings shall be submitted before manufacture.

27.1.2 Neatly and symmetrically arranged, with spare panels for futuredevelopment where shown, connected with purpose made adapters to permit theconnection of trunking and bus bar chambers so that all cables are enclosed.

27.1.3 Supplied where specified with header trunking or cable trays to run acrossthe top of the switchboard.

27.1.4 Given one coat of rust inhibiting paint, one of undercoat and one of enamel to BS colour exterior to be chosen by the Supervising Officer and whiteinterior.

28. Switchboard Connections And Termination Of Cables

28.1 The switchboard shall be provided with sealing boxes to suit the typecables.

28.1.1 Cable terminations shall be sweated lugs, compression lugs, or clamp typeterminals. Where compression type are specified they shall be made using anapproved type of lug and tool.

28.1.2 Cables shall be taken directly to the terminals of the switchgear exceptwhere otherwise specified.PVC or EPR Rubber insulated tails shall only be used where the length of cablecore from seal to connections exceeds 600mm.

28.1.3 Pinching screws which bear directly upon the cables shall not be used forequipment over 15 amps.

28.1.4 Outgoing cables shall not pass through the busbar chambers unlessspecified.

29. Distribution Fuseboards

29.1 All distribution fuseboards shall be:

29.1.1 Fitted with neutral bars having a separate terminal for each outgoingfuseway.

29.1.2 Firmly secured to the building structure by rawlbolts or similar approved

method, or to metal frames by means of nuts and bolts.29.1.3 Fitted with barriers between phases and to prevent accidental contact.

29.1.4 Fitted with typewritten fuse-chart mounted inside in transparent, non-flammable pockets securely mounted on the fuseboards. Charts shall provide fulldetails of outlets controlled, circuit numbers, fuse and cable sizes.

30. Labelling

30.1.1 All labels shall be of Ivorine or Traffolite laminate engraved with 5mmlettering at least and fixed with round-head, brass screws. Details of lettering tobe checked with the Supervising Officer if not specified.


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30.1.2 Labels on switchgear shall include:

Reference Number of the switchSpecified current ratingThe part of the distribution controlled

30.1.3 Labels on fuseboards shall include:

The reference numberThe service, e.g. lighting, power, standby etcThe reference number of the controlling switch

31. Wiring Accessories

31.1 Ceiling Roses

Ceiling roses shall be of the colour and type as specified and should be fixed tosecurely mounted conduit boxes. Plug in pattern ceiling roses shall be usedunless otherwise specified.

31.2 Lampholders

Lampholders shall be as specified and to the requirements of Section C41, NHSModel Engineering Specification.

31.3 Luminaires

Luminaire fittings shall be as detailed on the drawings and in the contract

specification.

31.4 Lighting Switches

Shall be as specified in Section C41, NHS Model Engineering Specification.

Mounted in deep pattern boxes except where plaster depths are specified.

Mounted in multi-gang assemblies where grouped.

Of the sunk type where used with flush wiring systems, otherwise of the surface

type.31.5 Socket Outlets

Shall be as specified on the drawings and the specification.

Shall be switched 13 amp. All sockets are to be flush mounted unless fitted intoMK powerlink trunking.

32. Earthing Generally

32.1 Shall be as specified in Section C41, NHS Model Engineering Specification.


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32.2 Earthing shall be carried out in accordance with the appropriate sections of the current edition of the IEE Wiring Regulations.

32.3 At all main switchgear positions an earth conductor consisting of copperstrip having a cross sectional area of 80 mm 2 shall be provided and allequipment including the metal sheath and armouring cables, the metalcase of all switches, distribution fuseboards and metal frames shall bebonded directly thereto.This earth strip shall be connected as specified to the main earthingsystem.Where earthing strips are to be laid in the ground they shall be servedwith anti-corrosive tape, be laid in sand and protected with tiles.A removable test link shall be provided inside the building as near aspossible to the earth electrode.

32.4 Earthing of sub-main distribution equipment shall be made by means of connections to the sub-mains cable where these are lead covered,armoured, MIMS or conduit. Where the Electricity Board provide an

earthed terminal or earthed cable sheath the earth strip shall be connectedand bonded to this point, with their permission in writing.

33. "As Fitted" Drawings and Maintenance Manuals

33.1 See General section

34. Guidance for work with Asbestos Insulation Board (A.I.B.)

34.1 See Site Rules section

35. Testing

35.1 The tests shall include all those required by the current IEE Regulationsand any others specified elsewhere in the Contract documentation or onthe drawings.

35.2 Test Instruments shall be:

35.3 As specified in Section C41, NHS Model Engineering Specification.

35.4 Provided by the contractorCorrectly calibrated and certified for the limits of accuracy necessary. If an instrument used is considered suspect by the Supervising Officer itshall be tested by an Authorised Standardising Laboratory. If thesuspicion is confirmed the cost of the test shall be borne by the contractor.Hand driven, generator type of test pressure 500 volts, except for mainscables where a 1000 volts generator shall be provided.Operated by suitably trained contractor's staff.

35.5 The tests shall be carried out by the contractor in the presence of theSupervising Officer at the completion of the installation or in any othersequence agreed with the Supervising Officer.The results are to be recorded on the IEE tests forms and handed to the


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Supervising Officer within 14 days of the tests being made.

35.6 The works WILL NOT be accepted for practical completion or handoveruntil the tests have all been satisfactorily completed and the certificateshanded over.


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File: FA007; Addenbrookes NHS TrustStandards for Contractorselectricalg/users/northfir/standards for contractors/electrical / March 2004

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APPENDIX 1

Maximum Spacing of Clips

OverallDiameter of Cable**

Non-armoured rubberpvc or lead-sheathedcables(Generally)

Armoured cables Mineral-insulated copper-sheathed or aluminium-sheathed cables

Horizontal*

Vertical * Horizontal*

Vertical * Horizontal*

Vertical *

Not exceeding9mm

200 250 - - 250 300

Exceeding

9mm and notexceeding15mm

300 400 350 450 350 400

Exceeding15mm and notexceeding20mm

350 450 400 500 450 500

Exceeding20mm and notexceeding40mm

400 550 450 600 - -

Note: For the spacing of supports for cables of overall diameter exceeding 40mm

and for single-core cables having conductors of cross-sectional area 300mm2

andlarger, the manufacturer's recommendations should be observed.

** for flat cables taken as the dimension of the major axis.

the spacing stated for horizontal runs may be applied also to runs at an angle of

more than 30o

from the vertical. For runs at an angle of 30o

or less from thevertical, the vertical spacing are applicable.

Under no circumstances will cabling be run unclipped or loose unless contained inconduit or trunking.

FA007 Stand Electrical

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Transcript of FA007 Stand Electrical