User manual | Section 5 Mechanical Standards of Materials and Workmanship

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Pricing document
Client Name :
Forestry Commission
Project Title :
Sherwood Pines Visitors Centre – Proposed WC Block
Project Nr :
141200
Section 5
Mechanical Standards of Materials and
Workmanship
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
CONTENTS
PART 2 :
STANDARDS OF MATERIALS AND WORKMANSHIP ..........................................................1
2:1.0 Regulations ................................................................................................................................ 1
2:2.0 Equipment Specification .......................................................................................................... 1
2:3.0 Pipework .................................................................................................................................... 2
2:4.0 Pipework & Fittings .................................................................................................................. 3
2:5.0 Erection of Pipework ................................................................................................................ 4
2:6.0 Pipework Supports ................................................................................................................... 5
2:7.0 Pipework Jointing ..................................................................................................................... 6
2:8.0 Welded Pipework ...................................................................................................................... 6
2:9.0 Headers ...................................................................................................................................... 7
2:10.0 Flanged Joints ......................................................................................................................... 7
2:11.0 Drain Points ............................................................................................................................. 8
2:12.0 Air Vents .................................................................................................................................. 8
2:13.0 Testing of Metal Pipework .................................................................................................... 8
2:14.0 Cleaning and Painting of Pipework ...................................................................................... 9
2:15.0 Valves and Cocks.................................................................................................................... 9
2:16.0 Gate Valves ............................................................................................................................. 9
2:17.0 Regulating and Double Regulating Valves.......................................................................... 9
2:18.0 Relief Valves.......................................................................................................................... 10
2:19.0 Gas Cocks .............................................................................................................................. 10
2:20.0 Thermo-meters ..................................................................................................................... 10
2:21.0 Pressure Gauges................................................................................................................... 10
2:22.0 Pressure & Temperature Test Plugs .................................................................................. 10
2:23.0 Identification of Pipework ................................................................................................... 11
2:24.0 Pumps .................................................................................................................................... 11
2:25.0 Ventilation Ductwork ........................................................................................................... 11
2:26.0 Air Handling Units and Fans ............................................................................................... 12
2:27.0 Extract Fans .......................................................................................................................... 12
2:28.0 Automatic Controls............................................................................................................... 12
2:29.0 Insulation Schedule.............................................................................................................. 13
2:30.0 Thermal Insulation ............................................................................................................... 13
2:31.0 Identify .................................................................................................................................. 15
2:32.0 Painting and Corrosion Protection ..................................................................................... 15
2:33.0 Electrical Continuity ............................................................................................................. 16
2:34.0 Penetration of Fire Barriers................................................................................................. 16
2:35.0 Commissioning and Testing General ................................................................................. 16
2:36.0 Maintenance of Plant During Commissioning and Testing............................................. 17
2:37.0 Commissioning Automatic Control Systems ..................................................................... 17
2:38.0 Boiler Performance Tests .................................................................................................... 17
2:39.0 Heating System Performance Tests .................................................................................. 18
2:40.0 Ventilation System Performance Tests ............................................................................. 18
2:41.0 Hot and Cold Water System Performance Tests ............................................................. 18
2:42.0 Sanitary ware ........................................................................................................................ 18
Section 2 – Page i of 19
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PART 2 :
Section 5
Mechanical Standards of
Materials and Workmanship
STANDARDS OF MATERIALS AND WORKMANSHIP
This section describes the installation of all materials and equipment generally and shall be
complied with in all instances unless otherwise later described in the Particular Specification
and/or indicated on the Project Drawings which may reference alternative installation
techniques or standards.
In the event of deviation from the Particular Specification, this section shall be read as the
minimum acceptable standard for the installation unless otherwise approved by the
Supervising Officer prior to the execution of any proposed, alternative works.
Provide and demonstrate all materials, fittings, accessories, for complete working systems as
specified including whole of plant, tackle, tools, instruments, scaffolding ladders, hoists,
fencing, temporary guards and other equipment and labour, both skilled and unskilled, to
unload, store, hoist and fix all materials, including standing scaffolding and hoists where
required.
Include any fitting or accessory obviously necessary for completion of the works always
provided that there will be no responsibility for design discrepancies, errors or omissions.
2:1.0
Regulations
Install to all relevant current British Standard specifications and Codes of Practice.
Comply with all applicable Regulations, Orders, By-laws, Acts of Parliament and other Rules of
Central and Local Government, Supply, Public Utility and any other accredited Authority.
Inform appropriate Authorities of works being undertaken, complete and deliver any
application form, and pay any fee and give all notices to test and connect.
2:2.0
Equipment
Specification
All equipment will comply fully with the specification details included in Part 2 and Part 3 of
this document. No change in specification, manufacture, model or type number etc., will be
permitted without the express written permission of the Supervising Officer. Where
manufacturers have updated or amended equipment specifications from those detailed
elsewhere, the Mechanical Sub-Contractor shall advise the Supervising Officer of this change,
in writing, as soon as possible.
Where no manufacturer or specification details have been included, then the selection of such
is left to the Mechanical Sub-Contractor. In making this selection he shall ensure that
equipment is fully suitable for its intended use, is of the required technical standard and
maintains the "quality of design and installation" stated elsewhere in this specification. In all
cases it shall be to the complete satisfaction of the Supervising Officer.
All equipment shall comply with the requirements of the "Regulations" listed in Part 1, clause
1:1:6.0, including all British Standards as applicable.
Equipment should be of EC manufacture where possible and shall bear the CE mark.
Quality Assured materials to BS 5750 should be considered in the selection of equipment
manufacture. Prior to any unspecified materials being ordered, the Contractor responsible for
the mechanical installation shall submit a list of proposed materials giving full details of such
materials. No unspecified materials shall be installed until approval of the proposed materials
has been obtained from the Employers’ representative.
Section 2 – Page 1 of 19
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Mechanical Standards of
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Use materials, components and equipment that conform in every detail to the specified
requirements which may be at variance with information lodged with certain manufacturers
and suppliers in respect of particular items of plant and equipment, or, where not so
specified, conform to the appropriate British Standard Specification.
Put forward in the tender, in the Alternatives Schedule or by separate letter, any specific
alternative price required and any preferred alternative make by submitting full details of the
alternatives and the associated variations to the tender price. It is stressed that the actual
tender price must be based on the materials, components and equipment specified.
2:3.0 Pipework
Pipework shall be as detailed in the following:
a)
Mild Steel Pipe (LTHW and Gas Services)
Mild steel pipework shall be manufactured in accordance with the provisions of BS 1387:1967
and subsequent amendments medium weight quality for LTHW and heavy weight for Gas.
b)
Copper Pipe (LTHW and Domestic Services)
Copper pipework shall be manufactured in accordance with the provisions of BS 2871:1971
and subsequent amendments Table X. All pipe and fittings shall bear an appropriate mark to
indicate that it has been manufactured in accordance with the provisions of the BSS.
c)
Plastic Pipe (LTHW and Domestic Services)
Plastic pipework shall be manufactured in accordance with the provisions of BS 7291 and
subsequent amendments. All pipe and fittings shall bear an appropriate mark to indicate that
it has been manufactured in accordance with the provisions of the BSS.
d)
Cast Iron (Above Ground Drainage)
Cast iron pipework shall be manufactured in accordance with the provisions of BS EN 877 and
subsequent amendments. All pipe and fittings shall bear an appropriate mark to indicate that
it has been manufactured in accordance with the provisions of the BSS.
e)
External Water Pipework
Water pipes shall be of Blue Modified High Density polyethylene manufactured in accordance
with the provision of BS 3284:1967 and BS 1972:1967 and their subsequent amendments
and to the Class as specified by the Water Supply Bylaws.
Any necessary adaptors for connection to valves and pipes of other materials shall be
provided. Pipework laid in the ground shall be installed with care and in such a manner that
pipework and fittings shall not be damaged due to ground movement.
Consideration shall be given, particularly for non-metallic pipes, to the depth at which the
pipe shall be laid, depending upon the size of the pipe, the location, width of the trench and
the class of bedding upon which the pipe will lie.
Buried cold water pipes shall be not less than 750mm below ground surface level as a
protection against frost damage.
Section 2 – Page 2 of 19
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f)
Section 5
Mechanical Standards of
Materials and Workmanship
Internal Cold Water Services Pipework
All CWS pipework shall be run in copper pipe to BS 2871 Part 1, Table X.
g)
Internal Gas Services Pipework
Internal Gas Services Pipework shall be run in Black Mild Steel tube to BS 1387 "Heavy" grade
and shall comply fully the latest Regulations of British Gas.
h)
External Gas Service Pipework
External gas service from the existing building to the gas meter in the new building shall be
carried out in yellow high density polyethylene tube, manufactured in accordance with the
provision of BS 7281 and to the class as specified by the Gas Safety Regulations.
i)
External Ground Loop Pipework
External ground loop pipework shall be installed to the specification provided by ICE energy.
2:4.0 Pipework
& Fittings
Pipe fittings shall be as detailed in the following:
a)
Butt Welded Fittings
Seamless carbon steel fittings for butt welding shall be manufactured in accordance with the
provisions of BS 1965: "Butt Welded Pipe Fittings for Pressure Purposes" Part 1:1963 "Carbon
Steel" and subsequent amendments. Butt welding fittings shall suit the associated pipework
to which they are to be welded and shall have a wall thickness not less than that of the pipe.
b)
Copper Capillary and Compression Fittings
Capillary fittings for use with copper pipe shall be of an approved soldered type with internal
shoulders and incorporating the necessary solder integral with the fitting.
They shall be manufactured in accordance with the provisions of BS 864 "Capillary and
Compression Tube Fittings of Copper and Copper Alloy" Part 2:1971 "Metric Units" and
subsequent amendments and the joints shall be made in accordance with the manufacturers
instructions with regard to cleaning, tinning, flux and the application of heat.
Compression fittings for use with copper pipe shall be of an approved manipulative type
manufactured in accordance with the provisions of BS 864: Part 2:1971 and subsequent
amendments Type A or Type B as specified for the service concerned.
All necessary copper to iron adaptors for connections to valves and other equipment shall be
provided.
Gunmetal fittings of Kontite or Yorkshire manufacture shall be used when specified for the
service concerned. Capillary or compression fittings for use under conditions where dezincification of the alloy is liable to be experienced shall be of gunmetal or other zincless alloy
Where pipework is to be chromium plated, compression fittings shall be used and shall be
Section 2 – Page 3 of 19
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Type B.
c)
Fusion / electrofusion weld joints.
Fusion or electrofusion type of jointing system shall be used for plastic pipework systems to
comply with BS 7291.
2:5.0 Erection
of Pipework
All pipework shall be erected to present a neat and tidy appearance, arranged to follow the
contour of walls and other structural members of the building. It shall give maximum
headroom and avoid the obstruction of windows and doorways. Pipework shall be installed
with due consideration for the location of other services with which its arrangement shall be
co-ordinated. Allowance should also be made during its erection for the thickness of
insulation thereon.
Vertical pipes are to be plumb and shall be fixed with 25mm clearance between the finished
face of the wall and the pipe or insulation thereon. Horizontal pipes near floors are to be
located with at least 75mm clearance between the finished face of the wall and the pipe or
insulation thereon.
Pipes shall be erected with continuous gradients rising in a suitable direction to clear air and
where a horizontal pipe is reduced in size in the direction of an air vent it shall be provided
with an eccentric reducing fitting. The gradient shall be appropriate to the service concerned
and unless otherwise indicated on the drawings is to be as follows:
a)
b)
Heating and Chilled Water (mains) 1 in 500
Gas and Compressed Air (mains) 1 in 500
Cutting and shutting will not be permitted unless approved by the Engineer. Pipework shall
be free from corrosion and the ends of all lengths, and cuts from standard lengths, shall be
trimmed square and reamed to the full bore of the pipe to remove burrs; the swarf shall be
cleared from the pipe.
Joints will not be permitted within the thickness of walls, floors, ceilings or other equally
inaccessible positions. All pipework, valves, fittings and equipment forming the general
installations shall be erected in a manner that will permit easy dismantling and convenient
accessibility for future repairs and replacements for items of plant.
Flanges or union connections shall be provided at valves and at suitable intervals to facilitate
erection of the pipework.
Particular attention is drawn to welded pipework where sufficient flanged joints shall be
provided to limit the length of pipe sections for convenient handling. Connections to
equipment shall be arranged by flanges or unions to facilitate removal.
Connections over 50mm diameter are to be made with flanges, but on pipes 50mm diameter
and under union connections may be used. Butt-welded fittings shall be used for all metal
pipes greater than 65mm bore. Bends and tees shall be of easy sweep or pitcher pattern
wherever possible, appropriate, and convenient. The use of bushes and hexagonal eccentric
reducing nipples for reducing the size of fittings will not be permitted. Long screw connectors
with backnuts will not be allowed.
Square elbows and square tees as well as straight or malleable nipples are not to be used
Section 2 – Page 4 of 19
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Mechanical Standards of
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unless authorised by the Engineer. Square tees and round elbows shall be used for
thermometer, thermostat, gauge and drain connections and air vents.
Round elbows may be used where pipework is exposed in rooms and where the use of an
easy sweep bend would throw the centre of pipe beyond an acceptable distance from the
wall.
Flat seated unions shall not be used; unions shall have bronze conical seats ground in.
All pipe systems shall be thoroughly flushed out when the installation has been completed.
All pipes, valves, fittings etc., shall be free from corrosion and internal obstruction. Pipework
showing signs of corrosion shall not be fitted.
All pipework and supports, other than galvanised or copper, shall be cleaned and painted one
coat of red oxide paint to afford protection during the course of erection. The paint shall be
applied immediately after the pipework has been installed.
Special care is to be observed to prevent dirt and rubbish entering the open ends of the pipes
during erection, and the open ends are to temporarily fitted with plastic or metal caps, plugs
or blank flanges during the progress of the work. Improvised plugs of wood, rag or paper
shall not be used. In the event of failure to comply with this instruction the Engineer shall
order pipework to be dismantled and cleansed internally to the extent which he may consider
necessary; at no cost to the Employer.
A valve terminating a disconnected pipe is not considered satisfactory to prevent the entry of
rubbish. The open end of the valve shall be fitted with a plug or flange as stated above. All
ferrous pipework and fittings other than galvanised shall be protected by one coat of red
oxide paint and this paint shall be applied as the work progresses.
2:6.0 Pipework
Supports
All necessary brackets, clips, hangers, and other pipe supports including bolts, nuts, washers,
backing plates, screws and plugs which shall be provided for the fixing and alignment of all
pipework, shall be approved by the Engineer.
All pipework shall be supported at the maximum centres given in the schedule included in this
specification. In the event of two or more pipes being carried by a single support the spacing
shall be selected for the shorter interval.
Under no circumstances shall a larger pipe be supported from a smaller pipe. All supports for
steel pipes shall be of a ferrous material and shall be galvanised where used with galvanised
pipe.
Pipework support distances in metres shall be:
Nominal Bore
of Pipe mm
Steel
Vertical
Horizontal
Copper
Vertical
Horizontal
15
20
25
32
40
2.0
2.5
2.5
2.5
3.0
2.0
2.5
2.5
2.5
3.0
1.5
1.5
1.5
1.5
2.0
1.5
1.5
1.5
1.5
2.0
Section 2 – Page 5 of 19
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50
65
80
100
125
150
200
Section 5
3.5
3.5
4.0
4.0
4.5
5.0
5.0
3.5
3.5
4.0
4.0
4.5
5.0
5.0
Mechanical Standards of
Materials and Workmanship
2.0
2.0
2.5
2.5
3.0
3.0
-
2.0
2.0
2.5
2.5
3.0
3.0
-
All supports for copper pipes shall be of polished brass where exposed to view; elsewhere,
they shall be rough finish. No ferrous supports will be permitted for non-ferrous pipes.
Where copper or steel piping is normally exposed to view in occupied places, the supports
shall be spaced at intervals one-half of those listed above, or as specially detailed elsewhere
in this Specification or on the drawings.
2:7.0 Pipework
Jointing
Screwed joints for steel pipes shall be made in accordance with the provisions of BS 21:1973
"Pipe Threads for Tubes and Fittings where Pressure Tight Joints are made on the Threads"
and subsequent amendments.
Screwed joints for copper pipes shall, unless otherwise specified, be made in accordance with
the provisions of BS 21:1973. The joints shall be clean threaded, pulled up tightly and made
with an approved jointing compound and long strand hemp. After joints have been formed
all surplus hemp shall be removed and the joint wiped clean as the work progresses.
When for the purpose of threading, pipes are held in a vice, care shall be taken to ensure
that the surface is not damaged. Any pipework so damaged shall not be fitted.
For galvanised tube care shall be taken to ensure that threads are carefully cut so that the
number of exposed threads are minimised. Exposed threads shall receive a coat of protective
red oxide paint after each joint has been made.
If the bead of a fitting is damaged during the installation the fitting shall be replaced.
2:8.0 Welded
Pipework
Pipework for welding shall be supplied with plain ends, and the bores at the end of adjacent
pipes are to match on site and bevelled to an 80 degree included angle of bevel.
All welding shall be carried out by welders holding a current recognised certificate of
competency for each method of welding, which shall be submitted to the Employers' Agent
for examination and approval. Welds made without this provision will be rejected.
Pipes up to 150mm bore may be welded by the metal-arc or Oxy-acetylene process but for
pipes larger than 150mm the metal-arc process shall be in accordance with the provisions of
BS 2971: Class II "Metal-arc Welding of Steel Pipelines" and "Pipe Assemblies for Carrying
Fluids" and subsequent amendments and the recommendations of the Institute of Welding,
using covered electrodes to BS 639:1976 "Covered Electrodes for the manual metal-arc
Welding of Carbon and Carbon Manganese Steel" and subsequent amendments.
No backing rings are to be used and joints shall have external reinforcement. Earthing clips
shall be of steel and are to be attached to the pipe itself - earthing from pipe fixings will not
be permitted.
Arrangements shall be made for the provision of an electrical supply for welding; or
Section 2 – Page 6 of 19
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alternatively, for the supply of an appropriate portable generator. Any charges so incurred
shall be included in the Tender.
Oxy-acetylene welding of joints shall be in accordance the provisions of BS 1821: 1857 "Class
1 Oxy-acetylene Welding of Steel Pipelines and Pipe Assemblies for Carrying Fluids" and
subsequent amendments; and with the publication "Welding of Mild Steel Pipes 1970"
published by the Heating and Ventilating Contractor Association and in accordance with the
provisions of BS 1724:1959 "Bronze Welding by Gas" and subsequent amendments for
copper pipes.
Care shall be taken to ensure that the welding metal or flux does not project into the bore of
the pipe. All welds shall be of good clean metal, free from slag inclusions and porosity, of
even thickness and even contour, well fused with the parent metal, annealed and hammered
upon completion and finished smooth.
All welded joints are to be stamped in a suitable position adjacent to the weld, to enable the
identity of the welder to be established. The identification coding shall be made available to
the Engineer prior to the commencement of installation. The Engineer shall have the
Authority to request that 2% of all welds be cut out for examination and testing, such tests
will be applied to any welded joint at the discretion of the Engineer.
The Engineer shall be present when welds are to be cut out and to witness such tests that
may be considered necessary to ensure that the full bore of the pipe is maintained at each
welded joint.
Bending tests, macro etching tests and any other method of testing may also be requested if
considered necessary by the Engineer and will be carried out in accordance with the
provisions of BS 709:1971 "Methods of Testing Fusion Welded Joints and Weld Metal in Steel"
and subsequent amendments. The entire cost of cutting out, testing and re-instalment shall
be included in the Tender. After inspection and any necessary tests, all welded joints shall be
protected by one coat of red oxide paint.
If any such weld is found to be inferior and not up to the standard required, two further
welds by the same welder will be similarly tested and if these also are found to be
unsatisfactory then the welder shall be taken off the works and all welds made by that welder
shall be cut and remade, the entire cost of the cutting out, re-instalment, testing and painting
shall be at the mechanical contractors own expense.
2:9.0 Headers
Where required headers shall be of neat construction with welded flanged ends and provided
with all necessary flanged stools to suit the sizes and positions of connections.
The stools shall be of sufficient length to clear the thickness of any insulation thereon and
permit the insertion of flange bolts.
All spare outlets, which may be specified, shall be provided with valves appropriate to the
service concerned and such spare valves shall be blanked off with plugs or blank flanges as
may be appropriate.
2:10.0 Flanged
Joints
All flanges for use with steel pipes shall be manufactured from mild steel in accordance with
the provisions of BS 4504 "Flanges and Bolting for Pipes Valves and Fittings" Part 1:1969
"Ferrous" and subsequent amendments, and to the Table appropriate for the pressure
specified.
Section 2 – Page 7 of 19
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Flanges for use with copper pipes shall be manufactured from bronze or gunmetal in
accordance with the provisions of BS 4504: Part 2:1972 "Copper Alloy and Composite
Flanges" and subsequent amendments and to the Table appropriate for the pressure
specified.
Flanges shall be machine faced, trimmed at the edges and spot faced for nuts. Boltholes
shall be drilled and not subsequently expanded. Flanges for welding shall be plain-faced slip
on neck type flanges. The tube shall terminate inside the bore 3mm from the face of the
joints and a sealing run shall be applied.
All flanged joints shall be flush and truly aligned and shall employ full-faced Taylors
corrugated metal ring coated on both sides with an approved jointing compound. Corrugated
metal rings for jointing oil pipes shall be of steel or nickel; all others shall be of brass.
All bolts and nuts shall be hexagonal headed bright steel in accordance with the provisions of
BS 4882:1973 "Bolting for Flanges and Pressure Containing Purposes", and no more than two
threads shall project beyond the nut.
For the purpose of cold-draw for expansion compensators, high tensile steel bolts shall be
used.
2:11.0 Drain
Points
Adequate provision shall be made for emptying all sections of all services as required for
maintenance purposes whether indicated on the drawings or not.
All boilers, cylinders, calorifiers and pumps together with all low points of pipework within
plant rooms shall be provided with draw-off gland cocks.
All other low points shall be provided with drain taps. Drain taps shall also be provided on the
flow and return of all heating and hot valves, and shall be located on the isolated side of the
valves whether indicated on the drawings or not.
Drain taps shall be in accordance with the provisions of BS 2879:1957 "Draining Taps Screw
Down Pattern" and subsequent amendments Type A with lockshield.
2:12.0 Air
Vents
Generally, all high points shall be fitted with Winns automatic air eliminators complete with
separate isolating valve. Pipework from AAV’s shall be extended and terminated at an agreed
location, generally at low level.
Where air bottles are approved for use, these shall be formed from pipe of equal bore to the
pipe being vented and of equal length to the bore plus 150mm. Each air bottle shall be
provided with a 6mm vent pipe welded into the top and terminating in a conveniently
accessible position, approximately 160mm above floor level, with a 6mm lockshield needle
valve. The needle valve shall be provided with a 6mm tailpiece with mitred end. Discharge
pipes shall terminate in agreed positions.
2:13.0 Testing
of Metal
Pipework
All pipework shall be tested hydraulically after assembly on site and before any insulation is
applied or pipework made inaccessible, to a pressure equal to twice the working pressure. If
the test pressure is greater than 6 bar the test pressure may be one and a half times the
working pressure.
The minimum test pressure for water pipes shall be 3 bar and for gas pipes the test pressure
Section 2 – Page 8 of 19
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shall be in accordance with the requirements of the Gas Company concerned.
Hydraulic pressure tests shall be carried out by means of a force pump which shall be locked
after the desired pressure is obtained.
The test pressure shall be registered at the lowest part of the system being tested and
maintained for a period of two hours during which time all parts must remain completely
watertight and no pressure loss becomes evident on the gauge. Any leakage must at once
be made good and the pressure test repeated until the desired test conditions are
maintained. During this period all welds on steel pipe shall be well hammered.
Boilers, chillers, cylinder pumps and any other ancillary items of equipment which may be
liable to damage by the test pressure, are to be isolated or suitably protected during the test,
and all necessary precautions taken. Any damaged equipment shall be replaced.
In order not to delay the works, sections of the pipework shall be pressure tested
independently as the work progresses. All necessary plugs, caps or blank flanges shall be
provided for testing and these shall be removed after the pressure test has been approved.
Seven days clear notice of any test shall be given to the Engineer in writing in order that
where deemed necessary, the Engineer shall witness the test.
2:14.0 Cleaning
and Painting of
Pipework
At completion of the work all rubbish and superfluous materials shall be cleared away and the
whole of the apparatus is to be clean and in working order.
All pipe, fittings, valves and other items of equipment are to be clean and any grease, dirt,
metal cuttings, sludge etc, which may have accumulated during the work shall be removed.
Any discoloration or other damage to parts of the building, its finishes or furnishings shall be
made good without additional cost to the Employer.
Pipework, fittings, valves, plant etc., except that which is thermally insulated or which is
otherwise specified to the contrary, shall be painted.
2:15.0 Valves
and Cocks
Valve and cocks shall be provided of the sizes given in accordance with the types specified for
the various services.
All valves and cocks shall be located in an accessible position for operational and
maintenance purposes.
2:16.0 Gate
Valves
Cast Iron flanged gate valves shall be in accordance with the provisions of BS 5150 "Cast Iron
Wedge and Double Disc Gate valves for General Purposes" and subsequent amendments.
They shall be provided with bronze trim and, unless otherwise specified, shall have non-rising
spindle. Valves shall be suitable for the working pressure of the service concerned.
Gunmetal and brass gate valves shall be in accordance with the provisions of BS 1952:1964
"Copper Alloy Gate valves for General Purposes" and subsequent amendments. They shall be
screwed, flanged or capillary type to suit the associated pipework and unless otherwise
specified, shall have non-rising spindles. Gate valves shall be suitable for the working
pressure of the service concerned. Gunmetal gate valves for oil lines shall have rising
spindles with back seatings.
2:17.0
Regulating and double regulating valves shall be cast iron construction with bronze trim
Section 2 – Page 9 of 19
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Regulating and
Double
Regulating
Valves
conforming with the provisions of BS 5152. The valves shall be of oblique pattern, suitable
for the service concerned, with characterised regulating plug and regulating sleeve giving
proportionate regulation.
Mechanical Standards of
Materials and Workmanship
The valve spindle and bonnet shall have back seating to enable it to be repacked under
pressure when fully open. Unless otherwise specified, regulating valves shall be provided
with a hand wheel.
2:18.0 Relief
Valves
Relief valves shall be of the full bore, enclosed spring loaded, lock up type with a discharge
pipe there from turned down to floor.
Relief valves for LPHW Heating systems shall be adjusted to lift at 0.7 bar in excess of the
working pressure or at 3.0 bar, whichever is the greater.
2:19.0 Gas
Cocks
Gas cocks shall be quarter turn copper alloy ball valves with P.T.F.E. seats and seals
manufactured to the relevant requirements of BS 5494:1978 and as tested and certified by
British Gas.
2:20.0 Thermometers
Thermometers shall be of a suitable type and pattern to permit them to be easily readable in
the position in which they are to be fitted.
Thermometers shall be of the angle pattern dial type. Each thermometer shall be graduated
to suit the temperature range.
Thermometer pockets shall be filled with graphite grease. Dial-type thermometers shall be
100mm diameter on pipework up to 80mm and for larger pipes 150mm diameter with chrome
plated bezel and shall be vertical or horizontal pattern with pocket.
2:21.0 Pressure
Gauges
Pressure gauges shall be of the 'Bourdon' type with 100mm diameter dial on pipework up to
80mm and for larger pipes 150mm diameter with chrome plated bezel and shall be vertical or
horizontal pattern with pocket. Each gauge shall be calibrated and graduated in bar for a
pressure range of zero up to twice the working pressure.
The gauge dial shall be marked with a red index line indicating the static pressure with the
system full and the boilers, pumps and other such equipment at rest.
For pressurised systems an additional green index line on the gauge dial shall indicate the
normal working pressure range of the installation concerned.
All gauges shall be provided with a 10mm connection to the associated pipework, and a lever
handled gauge cock for isolation.
2:22.0 Pressure
& Temperature
Test Plugs
Self-seating test plugs shall be provided at strategic points as appropriate for the
measurements of temperature and pressure. The test plugs shall be suitable for the system
operating temperature and pressure.
Generally test plugs shall comprise a self-sealing valve core enclosed within a brass body
fitted with a sealing cap with gasket. The plug shall be screwed into a 6mm half socket
welded to the pipe.
One thermometer and one pressure gauge for each range of conditions, for use with test
plugs, shall be provided.
Section 2 – Page 10 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
2:23.0
Identification
of Pipework
All new pipes shall be identified by code indication colour bands in accordance with BS
1710:1975 Appendix D. Colour bands shall not be provided on pipes which are to be painted
to match internal decorations.
Mechanical Standards of
Materials and Workmanship
Direction of flow indicating arrows shall be applied to all pipework.
2:24.0 Pumps
Pumps shall be installed as specified within the manufacturer’s literature to prolong pump life.
Small pumps shall be wall mounted using a suitable wall bracket with anti-vibration fixings.
The pump shall not be supported by the pipework alone. Larger pumps may be floor
mounted and again shall be mounted using a suitable stand with anti-vibration fixings.
Pumps shall be twin-head type with automatic changeover facility.
Isolation valves shall be located on either side of the pumps to aid replacement.
The pump and electrical feed connection shall be clearly labelled and identified.
2:25.0
Ventilation
Ductwork
a)
Galvanised Steel Ductwork
Galvanised steel duct shall be constructed from strip mill cold-reduced sheet steel
continuously hot dip galvanised to BS 2989:1975 "Hot Dip Galvanised Steel Sheet and Coil"
and subsequent amendments – Grade 22 Coating type C, and shall be fabricated in
accordance with the recommendations in the HVCA specification DW 142 issued by the
Heating and Ventilating Contractor Association, ESCA House, 32-34 Palace Court, Bayswater,
London W2 4JG.
b)
PVC Ductwork
PVC ductwork shall be constructed from unplasticised polyvinyl chloride in accordance with
the provisions of BS 3506:1969 "Unplasticised PVC Pipe for Industrial Purposes" and
subsequent amendments to Class O or from pressed or extended unplasticised polyvinyl
chloride sheet in accordance with BS 3757: "Rigid PVC Sheet" Part 1:1964 "Pressed Steel"
and subsequent amendments and Part 2:1965 "Calendered and Extruded Sheet" and
subsequent amendments. It shall be fabricated in accordance with the recommendation of
HVCA specification DW 151 - UPVC issued by the Heating and Ventilating Contractor
Association, ESCA House, 32-34 Palace Court, Bayswater, London W2 4JG.
Where PVC ductwork is to be thermally insulated or is not normally visible, Type A2 sheet
shall be used; elsewhere, Type A1 shall be used.
c)
Ductwork Fittings
Bends, branches, tees, transformations and other fittings shall be constructed from the same
material and to the same thickness as the associated straight ductwork and shall confirm with
the standard of fittings prescribed in the appropriate HVCA specification for the ductwork
material concerned.
d)
All balancing dampers, fire stop dampers, air turning vanes and access points
shall accord with the relevant clauses of DW 142 and the Local Fire Officers
requirements.
Section 2 – Page 11 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
e)
Air tight access doors shall be provided at strategic positions to allow
inspection and cleaning to be carried out.
f) All ductwork shall be insulated unless specifically stated. Insulation to external
ductwork shall be contained within an external waterproof membrane.
Access doors shall be provided at fans, silencers, bends, volume control dampers,
heating/cooling coils and all duct mounted equipment. Access doors shall also be provided at
6 metre intervals.
2:26.0 Air
Handling Units
and Fans
General construction of the units shall be able to withstand maximum fan static pressure
without deformation. The units shall be insulated complying with BS 476-6 and BS 476-7. The
insulation shall be fixed securely to the panel, and protected to prevent migration of fibre into
the air flow. The insulation is to provide thermal treatment and acoustic treatment. The
insulation shall be mineral fibre with a thickness of 50mm.
The framework shall be rigid enough to prevent distortion during transportation and after
final assembly on site. A continuous channel base shall be provided with the fan / AHU, which
is to be mounted on a concrete base in the Plantroom.
Anti-vibration mounts shall be provided within the air handling units and fans, to isolate the
fan and motor from other elements of the unit. Openings shall be provided for maintenance
where required with covers complete with opening devices, and sealed to prevent air leakage.
Ensure seals are designed for normal maintenance operations for a minimum of 10 years.
2:27.0 Extract
Fans
General construction of the units shall be able to withstand maximum fan static pressure
without deformation. The framework shall be rigid enough to prevent distortion during
transportation and after final assembly on site. In-line fans shall be mounted / suspended
using anti-vibration mounts to isolate the fans from the building structure. Fans located on
the roof shall be curb-mounted.
Extract fans serving toilet areas shall be twin-fan type with auto-changeover, complete with a
fault indicator light.
2:28.0
Automatic
Controls
The automatic control systems shall be electrically operated and shall provide temperature,
motor and equipment control, plant protection and fault indication.
a)
Electrical Wiring
All electrical wiring to and from control panels, sensors, detectors, motors, equipment etc.,
shall be carried out in accordance with the relevant sections of the Electrical Services
Specification
b)
Control Systems
A Controls Specialist shall be used for supply, installing and commissioning the general
control equipment and panels required to form the Automatic Control System.
c)
Exchange of Information
Section 2 – Page 12 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
The mechanical contractor shall be responsible for obtaining all necessary detailed electrical
information for the equipment provided under the Contract and for supplying such
information to the Controls Specialist.
The mechanical contractor shall thereafter be responsible for obtaining control panel wiring
diagrams and similar details from the controls specialist and issuing these for
approval/comment as required.
The mechanical contractor shall also be responsible for obtaining and issuing full details of all
electrical connections, terminal numbers and other such information as may be necessary for
full and proper wiring to and from control panels, plant, sensors, detectors, control valves,
controllers, motors etc.
2:29.0
Insulation
Schedule
Insulation thickness for non-domestic heating and water services installations to control heat
loss;
Application
CWS
CWS (External)
HWS
CHW
CHW (External)
LTHW
LTHW (External)
Ductwork
Ductwork (External)
2:30.0 Thermal
Insulation
Insulation Type
Class O Armaflex
Class O Armaflex
Coated with Armafinish to
manufacturer’s recommendations.
Class O Armaflex
Class O Armaflex
Class O Armaflex
Class O Armaflex
Coated with Armafinish to
manufacturer’s recommendations.
Class O Armaflex
Class O Armaflex
Class O Armaflex
Coated with Armafinish to
manufacturer’s recommendations.
Class O Armaflex
Class O Armaflex
Class O Armaflex
Coated with Armafinish to
manufacturer’s recommendations.
a)
The type of insulation and cladding are given for each item to be insulated in the
Schedule of Insulation. All pipework and ductwork shall be insulated unless indicated on the
drawings.
Due note shall be taken of the recommendations made to the Interim Statement of Health
and Safety Commission Advisory Committee on Asbestos - Asbestos Health Hazards and
Precautions - published 1977 by HMSA or subsequent amendments.
b)
Preliminaries
Before permitting any insulation to be applied, all pipework shall be clean and free from rust,
and erected in accordance with good practice and with proper clearance to permit the
application of insulation. All pipes shall be insulated independently and no two shall be
Section 2 – Page 13 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
lagged together. All the required heat tests, pressure tests and air leakage tests shall have
been satisfactorily carried out and approved and existing pipework and plant shall be suitably
protected, before insulation work may commence.
In order not to delay building operations where pipework will eventually be encased or made
inaccessible within the building structure, if necessary, sections of the installation shall be
insulated independently as the work proceeds. All thermal insulation shall be carried out by a
specialist in insulation work.
Skilled labour only shall be employed and the materials and workmanship shall be of the
highest quality, and every care shall be exercised to keep the premises in a clean and tidy
condition.
c)
Application of Insulation for Pipework
All thermal insulation shall be applied where specified and in accordance with the Schedule of
Insulation in a careful and efficient manner to give a smooth, homogeneous and lineable
surface and to present a neat and symmetrical appearance.
Rigid sections shall be concentric and accurately matched for thickness. Damaged ends will
not be acceptable and any irregular or badly finished surfaces shall be stripped and re-lagged
to the satisfaction of the Engineer.
The insulation on all vent and relief pipes shall be continued to a height of at least 150mm
above the water level in the pipe.
d)
Application of Protective Cladding for Pipework
Protective cladding shall be applied to the insulation using material in accordance with the
Schedule of Insulation.
e)
Identification of Pipework
All pipes except those in office and toilet areas shall be identified by code indication colour
bands in accordance with BS 1710:1975 Appendix D. Colour bands shall not be provided on
pipes which are to be painted to match internal decorations.
f)
Insulation of Cold Water Cisterns
Storage tanks and cisterns shall be insulated with foil faced mineral wool slabs firmly fixed
with wire netting, to BS 6700.
g)
Mineral Wool Insulation
Mineral Wool rigid section insulation shall be in accordance with the provisions of BS 3968:
Part 5:1969. Slab and roll insulation shall have densities of 48Kg/m3 and 32Kg/m3
respectively.
Mineral wool insulation for pipes, including fittings, shall be applied as described in the
Schedule of Insulation and in accordance with the manufacturers recommendation.
h)
Insulation Adhesive
Section 2 – Page 14 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
Insulation adhesive shall be applied as recommended by the manufacturer.
i)
Polyisobutylene Cladding (External Services)
j)
Application of Insulation for Ductwork
All thermal insulation shall be applied where specified and in accordance with the Schedule of
Insulation in a careful and efficient manner to give a smooth, homogeneous and lineable
surface and to present a neat and symmetrical appearance.
Rigid sections shall be concentric and accurately matched for thickness. Damaged ends will
not be acceptable and any irregular or badly finished surfaces shall be stripped and re-lagged
to the satisfaction of the Engineer.
Comply in general with BS 5422 and the British Standards publications referred to therein.
Also comply with BS 5970. Description of terms as BS 3533. Ensure that thermal conductivity
values are in accordance with BS 874 and BS 2972.
Plastic protective finish shall comprise polyisobutylene sheeting with overlaps neatly sealed
down with a suitable solvent.
2:31.0 Identify
After the thermal insulation and cladding as required has been completed and accepted the
whole of the installation shall be identified in full compliance with BS 1710.
Pipeline contents shall be identified by purpose made coloured identification bands securely
fixed to the manufacturers recommendations. Adjacent to each identification band self
adhesive labels having white lettering shall be attached identifying the pipeline contents.
Self-adhesive white flow directional arrows shall be attached to the identification band in the
direction of flow of the pipeline contents. All uninsulated pipelines shall be painted in
accordance with BS 1710, unless otherwise approved or described by the Engineer for
aesthetic reasons.
Each and every valve shall be complete with a valve tag, having a reference number relating
to the valve chart specified elsewhere. Each valve tag shall be manufactured from 25mm
diameter traffolyte having white background and black engraved reference number 12mm in
height.
Each valve tag shall be supplied complete with a key ring and chain type fixing with all valve
tags securely fixed to the appropriate valve. All plant and equipment shall be complete with
either a brass or traffolyte label securely fixed to the items describing the system being
served, unit model reference, capacity, size or duty, full electrical motor details and
manufacturers name.
Full details including size, shape and text of all valve tags or other plant and equipment labels
shall be forwarded to the Engineer for approval before fixing. Full reference shall be made to
all service identification within the operating and maintenance manuals.
2:32.0 Painting
and Corrosion
All steel pipework installed internally, once free from rust and scale, shall be painted with two
coats of red oxide primer paint.
Section 2 – Page 15 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
Protection
Each coat shall be applied separately with a minimum of 24 hours between the application of
each coat to permit complete drying.
All gas piping shall be painted yellow in accordance with BS recommendations.
All steel brackets, hangers, supports and support structures, wheresoever situated, shall once
free from rust and scale, be painted as above but with an additional coat of black heat
resistant paint.
Further painting of service shall be carried out in accordance with BS 1710 as required for
identification.
2:33.0
Electrical
Continuity
The whole of the pipework and sheet metal ductwork installations shall be electrically
continuous up to and including the plant and equipment.
Earth bonding shall be provided across all non-electrical continuity items within the
mechanical systems
2:34.0
Penetration of
Fire Barriers
The mechanical contractor shall ensure within the tender that all parts of the mechanical
systems which penetrate a fire barrier comply in all respects to the District Surveyors and
Local Authority recommendations.
2:35.0
Commissioning
and Testing
General
The Mechanical Services shall be commissioned and tested to a programme of works and this
shall be incorporated in the programme for the contract following approval by the Engineer.
The costs for commissioning all systems and for carrying our any specified tests shall be
included in the tender sum.
The mechanical contractor shall assume responsibility for the full and complete
commissioning of all of the mechanical installation, including the Mercury air handling unit.
The mechanical contractor shall be responsible to ensure that the design intent air flow rates
are delivered at each of the ventilation grilles within the building and shall be responsible for
ensuring that, if this is not the case, all necessary remedial works shall be carried out and
completed to the EA’s satisfaction before the building is handed over
Commissioning shall mean the advancement of all the Mechanical Services from the State of
Static completion to full working order adjusted to the design requirements.
On completion of the Mechanical Services Installation or any section thereof the mechanical
contractor will be required to carry out whatever tests are required to demonstrate that the
systems fully meet all the design requirements, including the provision of all necessary
pressure and temperature test points and instruments.
Prior to pressure testing, water systems shall be filled with water and flushed out to remove
all foreign matter, chemicals shall be added if necessary to ensure the systems are
thoroughly cleaned. Any plant which may be damaged by the cleaning process shall be
disconnected. Flushing, cleaning and pre-commissioning shall be carried out in accordance
with BSRIA Application Guides 1/89 and 8/91. Allowance shall be made to provide all
Section 2 – Page 16 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
connections and equipment specified in these publications.
After pre-commissioning cleaning, all water pipework shall be hydraulically tested in
accordance with Section 2.12.
Ventilation systems shall be cleaned and prepared prior to commissioning in accordance with
BSRIA Application Guide.
Domestic water services after pre-commissioning cleaning and hydraulic testing shall be
sterilised by the application of chlorine.
Air and water systems shall be checked and treated to achieve totally hygienic conditions in
accordance with Health and Safety Series booklet HS (G) 70.
All plant shall be commissioned by the manufacturer where the manufacturer offers this
service.
On completion of any electrical installation, tests shall be carried out as laid down in the 16th
Edition of the IEE Wiring Regulations.
All testing shall be witnessed by the Engineer and on completion of the test, certificates shall
be provided by the mechanical contractor and handed to the Engineer together with two
copies of each of the test results upon which the certificates are based. Further copies shall
be included in the maintenance/operating instruction manual.
Proper records shall be made and these are to be embodied in the maintenance/operating
manual.
The mechanical contractor is to provide all instruments necessary for testing and
commissioning.
The contractor shall allow for revisiting the building for seasonal commissioning. All plant and
equipment shall be checked for correct operation and re-commissioned if necessary during
the following summer and following winter from handover.
2:36.0
Maintenance of
Plant During
Commissioning
and Testing
The plant shall be maintained in accordance with the manufacturers instructions throughout
the commissioning and testing period and until the plant is handed over to the employer.
Records of the maintenance procedures and record drawings shall be kept for each
Mechanical Services System and these records shall be handed to the Engineer.
Properly trained staff shall be made available to maintain the plant and any repairs or
replacements that may be necessary shall be carried out before the plant is handed over.
2:37.0
Commissioning
Automatic
Control
Systems
All automatic control systems shall be commissioned in accordance with the CIBSE Code
Series C - The Commissioning of Automatic Control Systems.
2:38.0 Boiler
Performance
Tests
Boiler systems shall be commissioned in accordance with the CIBSE Commissioning Code
Series B - Boiler Systems, and in accordance with any specific manufacturers requirements.
Section 2 – Page 17 of 19
RIDGE
Mechanical Specification
Client Name :
Forestry Commission
Section 5
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Mechanical Standards of
Materials and Workmanship
Boiler Performance Tests shall be carried out by the manufacturers commissioning engineers.
2:39.0 Heating
System
Performance
Tests
The Heating Systems shall be commissioned in accordance with the CIBSE Commissioning
Code Series W -Water Distribution System.
2:40.0
Ventilation
System
Performance
Tests
All air distribution and extract systems shall be commissioned in accordance with the CIBSE
Commissioning Code Series A - Air Distribution System, High and Low Velocity. All ductwork
shall be pressure tested in accordance with DW 143. The mechanical contractor shall assume
responsibility for the full and complete commissioning of all of the mechanical installation,
including the Mercury air handling unit. The mechanical contractor shall be responsible to
ensure that the design intent air flow rates are delivered at each of the ventilation grilles
within the building and shall be responsible for ensuring that, if this is not the case, all
necessary remedial works shall be carried out and completed to the EA’s satisfaction before
the building is handed over
2:41.0 Hot and
Cold Water
System
Performance
Tests
Hot and cold water services system performance tests shall be carried out in accordance with
the CIBSE Commissioning Code Series W - Water Distribution System.
Flow rates given in BS6700 shall be demonstrated under all likely working conditions
Hot water circulation systems shall be balanced to provide water at all draw-offs within the
recommended times.
Temperatures and draw-off times shall be taken and recorded to demonstrate that the
conditions recommended for water hygiene have been achieved.
After satisfactory completion of final testing, the following sterilisation procedures shall be
carried out by a Specialist Contractor.
The whole of the process shall be carried out in accordance with the requirement of the Local
Water Supply Authority and BS6700.
Sterilising water shall be disposed in compliance with the requirements of the Water
Authority.
Detail records shall be maintained for sterilisation procedures carried out. A copy of
Sterilisation Certificates for all parts of the systems shall be submitted complete with analysis
of test samples, or sterilisation works are to be carried out by the Specialists Sub Contractor.
2:42.0 Sanitary
ware
For details of sanitary ware please refer to Architects specification. The mechanical contractor
shall however be responsible for all final connection to sanitary ware.
Section 2 – Page 18 of 19
ofadb=
Pricing document
Client Name :
Forestry Commission
Project Title :
Sherwood Pines Visitors Centre – Proposed WC Block
Project Nr :
141200
Section 6
Electrical Standards of Materials and
Workmanship
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
CONTENTS
PART 2 :
ELECTRICAL STANDARDS OF MATERIALS AND WORKMANSHIP ...................................... 3
2:1:1.0 Regulations ....................................................................................................................... 3
2:1:2.0 Equipment Specification .................................................................................................. 3
2:1:3.0 Identify.............................................................................................................................. 4
2:1:4.0 Painting and Corrosion Protection .................................................................................. 5
2:1:5.0 Voltage Pressure .............................................................................................................. 5
2:1:6.0 System Type ..................................................................................................................... 6
2:1:7.0 Cables General ................................................................................................................. 6
2:1:8.0 Identification of Cables .................................................................................................... 6
2:1:9.0 Sizing of Cables ................................................................................................................ 7
2:1:10.0 Minimum Working Temperature ................................................................................... 7
2:1:11.0 General Installation........................................................................................................ 7
2:1:12.0 Bending ........................................................................................................................... 7
2:1:13.0 PVC Insulated Cables..................................................................................................... 7
2:1:14.0 PVC Insulated/PVC Sheathed Cables............................................................................ 8
2:1:15.0 Flexible Cables or Cords ................................................................................................ 8
2:1:16.0 Mineral Insulated Cables ............................................................................................... 8
2:1:17.0 Duct Installations ......................................................................................................... 10
2:1:18.0 PVC/XLPE Insulated, Armoured and PVC or LSF Sheathed Cables .......................... 11
2:1:19.0 Cable Supports ............................................................................................................. 12
2:1:20.0 Underground Cables .................................................................................................... 13
2:1:21.0 Protection of Cables ..................................................................................................... 14
2:1:22.0 Fixed Conduit Systems ................................................................................................ 14
2:1:23.0 Flexible Conduits .......................................................................................................... 16
2:1:24.0 Wiring of Conduits ....................................................................................................... 17
2:1:25.0 Trunking Installation.................................................................................................... 17
2:1:26.0 Cable Basket/Tray Installation .................................................................................... 18
2:1:27.0 Earthing ........................................................................................................................ 19
2:1:28.0 Earth Electrode System ............................................................................................... 20
2:1:29.0 Main Earth Bar.............................................................................................................. 20
2:1:30.0 Protective Conductors .................................................................................................. 20
2:1:31.0 Equipotential Bonding of Other Service mains .......................................................... 20
2:1:32.0 Equipotential Bonding of Exposed Conductive Parts ................................................ 21
2:1:33.0 Equipotential Bonding of Extraneous Conductive Parts ............................................ 21
2:1:34.0 General Bonding Requirements .................................................................................. 22
2:1:35.0 General Fixings for Equipment.................................................................................... 22
2:1:36.0 Main Switch Panels, Isolators and Fused Switchgear ............................................... 23
2:1:37.0 Socket Outlets and Fused Connection Units .............................................................. 25
2:1:38.0 Lighting - General Circuit Wiring ................................................................................ 25
2:1:39.0 Luminaire Fixings ......................................................................................................... 26
2:1:40.0 Luminaires .................................................................................................................... 27
2:1:41.0 Lamps and Lamp Holders ............................................................................................ 27
2:1:42.0 Wiring for Mechanical Services ................................................................................... 27
2:1:43.0 Asbestos........................................................................................................................ 28
Part 2 – Page 1 of 31
RIDGE
Electrical Specification
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Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
2:1:44.0 Poly Chlorinated Biphenyls .......................................................................................... 28
2:1:45.0 CFC’s ............................................................................................................................. 28
2:1:46.0 Treatment for Shock Notices ...................................................................................... 28
2:1:47.0 Key Box and Keys ........................................................................................................ 28
2:1:48.0 Rubber Mats ................................................................................................................. 29
2:1:49.0 Inspection and Testing ................................................................................................ 29
2:1:50.0 Commissioning ............................................................................................................. 30
Part 2 – Page 2 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
PART 2 :
Electrical Workmanship
ELECTRICAL STANDARDS OF MATERIALS AND WORKMANSHIP
This section describes the installation of wiring, materials and equipment generally and
shall be complied with in all instances unless otherwise later described in the Particular
Specification and/or indicated on the Project Drawings which may reference alternative
installation techniques or standards.
In the event of deviation from the Particular Specification, this section shall be read as the
minimum acceptable standard for the installation unless otherwise approved by the
Contract Administrator prior to the execution of any proposed, alternative works.
Provide and demonstrate all materials, fittings, accessories, for complete working systems
as specified including whole of plant, tackle, tools, instruments, scaffolding ladders, hoists,
fencing, temporary guards and other equipment and labour, both skilled and unskilled, to
unload, store, hoist and fix all materials, including standing scaffolding and hoists where
required.
Include any fitting or accessory obviously necessary for completion of the works always
provided that there will be no responsibility for design discrepancies, errors or omissions.
2:1:1.0
Regulations
Install to all relevant current British Standard specifications and Codes of Practice.
Comply with all applicable Regulations, Orders, By-laws, Acts of Parliament and other
Rules of Central and Local Government, Supply, Public Utility and any other accredited
Authority including the Regulations for Electrical Installations BS 7671 (The "IEE Wiring
Regulations").
Inform appropriate Authorities of works being undertaken, complete and deliver any
application form, and pay any fee and give all notices to test and connect.
2:1:2.0
Equipment
Specification
All equipment will comply fully with the specification details included in Part 2 and Part 3
of this complete document. No change in specification, manufacture, model or type
number etc., will be permitted without the express written permission of the Contract
Administrator. Where manufacturers have updated or amended equipment specifications
from those detailed elsewhere, the Main Contractor shall advise the Contract
Administrator of this change, in writing, as soon as possible.
Where manufacturers, suppliers or installers of products are NOT identified by name
select products that are fully suitable for its intended use, is of the required technical
standard and comply in all respects with the specification and, as and when requested,
demonstrate such compliance.
Where manufacturers, suppliers or installers of products are identified by name, or names,
but no reference is made to "Or approved" equivalent use these exclusively.
Where manufacturers, suppliers or installers of products are identified by name, or names,
but reference is made to "Or approved" equivalent alternatives may be selected and shall
be submitted to the Contract Administrator for approval.
Where manufacturers, suppliers or installers of products are identified by name, or names,
Part 2 – Page 3 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
but reference is made to "Or approved" equivalent the submitted tender must include the
named or one of the named suppliers. Alternatives may be selected and shall be
submitted to the Contract Administrator for approval, separately.
Check that any proposed alternatives comply with any stated British (or other equivalent
recognised International) Standards. Confirm equivalence in quality, operation and space
requirements to those items, which have been specified by name. If, and when requested
demonstrate the proposed alternative is fully equivalent to the specified item and identify
any constructional, cost, programme, maintenance or other differences.
All equipment shall comply with the requirements given within the specification including
all British Standards as applicable.
Equipment should be of EC manufacture where possible and shall bear the CE mark.
Quality Assured materials to BS 5750 should be considered in the selection of equipment
manufacture. Prior to any unspecified materials being ordered, the Main Contractor
responsible for the electrical installation shall submit a list of proposed materials giving full
details of such materials. No unspecified materials shall be installed until approval of the
proposed materials has been obtained from the Contract Administrator.
Use materials, components and equipment that conform in every detail to the specified
requirements which may be at variance with information lodged with certain
manufacturers and suppliers in respect of particular items of plant and equipment, or,
where not so specified, conform to the appropriate British Standard Specification.
Put forward in the tender, in the Alternatives Schedule or by separate letter, any specific
alternative price required and any preferred alternative make by submitting full details of
the alternatives and the associated variations to the tender price. It is stressed that the
actual tender price must be based on the materials, components and equipment specified.
2:1:3.0 Identify
Identify all provided items, circuits, cable cores, busbars, trunking etc., except where use
and connection is reasonably obvious for operation and maintenance, to BS 1710 and IEE
Regulations with circuit lists and/or labels engraved with as applicable name, number,
manufacture name, reference number and date, capacity, rating, speed, frequency,
voltage, full load and starting current, phase(s) and all relevant details for operation and
maintenance.
Provide typed circuit lists on plastic film under clear Perspex in interior of each item giving
distributor name, number and location and each circuit number, point numbers, type and
wattage connected, cable size and protection device and rating.
Labels to be 4mm thick clear plastic with 6mm high black filled letters on reverse side two
screw fixed to a logical external surface of switch and distribution equipment, etc.; for
terminals adjacent to or on the block and for busbars, etc., coloured to indicate phase
fixed to the bars. Provide additional label with 10mm high red letters reading 'CAUTION V
VOLTS' where V exceeds 250 volts.
Main switchboard label letters to be 12mm high, one label with black letters giving name
and main function and second label with red letters giving IEE Regulation instructions as
to periodic inspection and testing with adjacent removable chart on plastic film under
Part 2 – Page 4 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
clear Perspex cover for inspection and test records.
Provide on outer face of all sub station, main switchroom and rising duct doors labels with
75mm high red letters "DANGER 400 VOLTS" or "Treatment for Electric Shock" instruction
on substantial card as produced by the "The Electric Review" or equal.
Provide diagram for each main and sub switchboard of the electrical distribution from that
board giving circuits and locations of all items by number, principle cable sizes and giving
all code details and colours, one copy printed onto plastic film wall mounted under clear
Perspex adjacent to the board concerned with further copies in the instruction manual.
Modify these methods to those already in use by the Purchaser where so specified or later
directed and amend or replace any effected existing identification.
Submit for approval all proposed identification details with specimen circuit lists.
2:1:4.0 Painting
and Corrosion
Protection
Paint all electrical equipment supplied which requires painting to include repainting all
items supplied which have become marked or damaged and so that the finish of any run
or group has a consistent finish and to all ferrous supports and parts installed externally,
in plant rooms or in tunnels, ducts, shafts, etc. and/or otherwise specified.
For items to be painted, thoroughly descale, wire brush and paint one coat of red or grey
oxide before erection followed by a second coat after erection followed by an undercoat
and two top coats of paint to provide a hard gloss finish where internal with third coat to
provide a hard matt finish where external.
All paints to be suitable for their purpose, be heat resisting where necessary and paint
colours to be approved prior to commencement of final painting.
Where a galvanised finish is specified and is found to be unobtainable within the time
required obtain equipment of standard finish and galvanise or zinc spray by the 'Schori'
process.
Equipment to be so treated to be completely dismantled afterwards
re-assembled with special attention to earth contact surfaces to ensure metal contact
without the intervention of the substance with which they have been treated.
Where dissimilar metals and/or materials are used together such further precautions are
to be taken to avoid chemical or electrolytic action occurring. This particularly refers
when aluminium or aluminium alloys are used.
2:1:5.0 Voltage
Pressure
Provide electrical installation suitable for the available supply assuming a maximum
voltage fluctuation of plus or minus 10%. Throughout this specification the following
ranges of nominal voltage (Root Mean Square (RMS) values for Alternating Current (AC))
are used: Extra Low Voltage
Normally not exceeding 50Va.c. or 120V ripple free d.c.
whether between conductors or to earth.
Low Voltage
Normally exceeding Extra Low Voltage, but not
exceeding 1000Va.c. or 1500Vd.c.between conductors,
or 600Va.c or 900Vd.c. between conductors and earth.
Part 2 – Page 5 of 31
RIDGE
Electrical Specification
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Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
High Voltage
Normally exceeding Low Voltage.
Reduced Low Voltage
The nominal phase to phase voltage does not exceed 110
volts and the nominal phase to earth voltage does not
exceed 63.5 volts.
Note: The minimum insulation requirement for all cables installed for extra low voltage,
and low voltage installations shall be 450/750V RMS AC for one minute.
2:1:6.0 System
Type
Unless otherwise stated in the Particular Specification, the electrical supply shall be
sourced from the local supply authority network characterised with a TN-C-S earthing
arrangement, having a combined neutral and earth (CNE) at the point of service entry to
the building with separate neutral and protective conductors throughout the installation.
2:1:7.0 Cables
General
All cables shall be supplied and installed in accordance with this specification and
indicated on the project drawings.
All cables, irrespective of voltage rating and construction, shall be installed in one
complete length, from source to point of utilisation, with no joints being permitted except
with the express permission of the Contract Administrator, this permission being given in
writing.
All cables and flexible cords, in addition to complying with the relevant British Standards,
shall be approved under the British Approvals Services for Electric Cables (BASEC).
2:1:8.0
Identification
of Cables
All cables installed shall be identified either by number or colour and shall comply with the
IEE Regulations.
Phase identification and relationship to number/colour coding shall be as follows:
Three Phase
Phase L1
Phase L2
Phase L3
Neutral
CPC
-
Single Phase
Live Conductor
Neutral Conductor
CPC
Brown
Black
Grey
Blue
Green/Yellow
-
Brown
Blue
Green/Yellow
The sequence of terminations at switchgear shall be 1, 2, 3 or Brown, Black, Grey when
viewed from the front of the switchgear, and reading left to right. Where three phase
equipment is used, the connection sequence shall be as above through all control
equipment termination stages. Where three-phase equipment requires rotation reversal,
the phase connection modifications shall be carried out at the penultimate connection
point to the equipment served. I.e. outgoing terminals of a motor starter or outgoing
terminals of the means of local isolation.
Extra low voltage systems shall be identified by colour as detailed in the Particular
Part 2 – Page 6 of 31
RIDGE
Electrical Specification
Forestry Commission
Client Name :
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
Specification.
2:1:9.0
Sizing
of Cables
Unless otherwise specified the conductor size of all cables have been selected in
accordance with Appendix 4 of the IEE Regulations. Due consideration has been given to
the effect of voltage drop and to the de-rating factors stated for the type of overload
protection used, grouping factor and environmental conditions. Cable routing shall take
account of these calculations and the Main Contractor shall ensure that the specified
maximum voltage drops are not exceeded. This requirement shall be met by installing
circuits the most direct route, not necessarily the most convenient route.
The minimum conductor size shall be 1.5mm² for all fixed wiring systems and 0.75mm²
for flexible cables and cords, unless otherwise stated.
2:1:10.0
Minimum
Working
Temperature
In order to avoid the risk of damage to cables containing PVC in their construction, cables
of this type shall not be handled unless the ambient temperature is above 0°C and has
remained so for the previous 24 hours.
The same conditions shall apply to LSF cables.
2:1:11.0
General
Installation
Cables shall be installed carefully and the correct procedure shall be adopted in their
handling and in the manoeuvring of the associated cable drums to prevent mechanical
damage, kinking and abrasion of the external sheath.
Due allowance shall be made for building movements and ground subsidence and cables
shall not be laid under tension, including when installed within a containment system.
Where possible all cables laid in trenches shall be snaked.
2:1:12.0
Bending
Where cables are required to deviate from a normally straight route, the internal radius of
the bend shall not be less than the minimum radii stated in the IEE Regulations or as
detailed below, depending on the construction of the cables involved.
XLPE or PVC cables (circular
Cu or Al conductors) - Armoured
or non-armoured
-
6
times overall diameter
XLPE or PVC cables (shaped
Cu or Al conductors) - Armoured
or non-armoured
-
8
times overall diameter
MICC cables
-
6
times overall diameter
For other types of cables the manufacturer's recommendations shall be adhered to.
2:1:13.0
Insulated
Cables
PVC
PVC or LSF insulated single core cables shall be installed only in conduit, trunking or a
totally enclosed panel affording complete protection. They shall be 450/750v grade with
copper conductors, a minimum size of 1.5mm² and shall comply with BS 6004 Table
except in Boiler Rooms and areas with temperatures above 40ºC where they are to be
elastomer butyl rubber insulated cables to BS 6899.
Single core cables shall have a stranded composition. Single core cables having a single
solid drawn conductor shall not be used.
Part 2 – Page 7 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
For single-phase circuits, the phase, neutral and earthing conductors shall not be installed
in separate containment systems. Similarly, for 3 phase, or 3 phase and neutral circuits,
all phase, neutral and earthing conductors of each circuit shall be installed in the same
conduit or trunking and, in the case of trunking only, all cables for each circuit bound
together using PVC insulation tape where practicable.
2:1:14.0
PVC
Insulated/PVC
Sheathed Cables
PVC insulated and PVC sheathed cables shall be either twin or three core with earth
continuity conductor incorporated. They shall be 300/500v grade with copper conductors,
and comply with BS 6004 Tables 4 and 5, cable reference 6242YH and 6243YH.
Single core insulated and sheathed cables shall not be utilised for final circuit distribution.
Care shall be taken that the outer sheathing is not cut back beyond the limits of the
terminal box or distribution board.
Where the sheathing is cut back to reveal the phase and neutral conductors and bare
earth conductor, the earth conductor shall be sheathed with a green/yellow PVC sleeving
in accordance with BS 7671.
Cables concealed in ceiling spaces shall be installed parallel and perpendicular to ceiling
structures. Where cables are concealed in the cavities of proprietary brands of
partitioning, behind the inner cladding of external walls or flush mounted where walls are
plaster finished, the protection requirements of BS 7671 shall be adhered to.
Cables shall be supported with high impact plastic clips. Where surface mounted, the
cables shall be secured at intervals not exceeding 150mm both horizontally and vertically.
Cable entries to all switch and socket boxes, and distribution boards, shall have PVC
grommets, or continuous grommet strip fitted.
2:1:15.0
Flexible Cables
or Cords
Flexible cables or cords shall be used for final connections to stationary equipment, to
pendant luminaires or to fixed luminaires where wiring is run within the fitting and subject
to high ambient temperature.
Flexible cables and cords shall be 300/500v grade PVC insulated and sheathed to BS 6500
Table 16 for normal general purpose use, 85°C heat resisting PVC insulated cable and
sheathed to BS 6500 Table 12 for final connection to luminaires and other portable
appliances subject to high temperatures and 150°C rubber insulated and braided cable to
BS 6007 for high ambient temperatures or final connection to fixed luminaires where the
wiring runs adjacent to control gear or lamps. Generally all flexible cables or cords shall
be selected in accordance with the BS 7671.
Multicore flexible cables or cords shall have an overall insulation of white round section
PVC or butyl rubber and shall contain an earth conductor in all instances.
A minimum conductor size of 0.75mm² copper shall be employed unless specified
otherwise.
2:1:16.0
Mineral
Mineral insulated copper sheathed cables shall be installed where detailed in the Particular
Specification or where indicated on the drawings. Cables shall comply with BS 6207, Part
Part 2 – Page 8 of 31
RIDGE
Electrical Specification
Client Name :
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Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Insulated
Cables
Electrical Workmanship
1. MICS cable used for low voltage lighting and power circuits shall be 1000v rated
"Heavy Duty" grade. For fire alarm systems 600v rated "Light Duty" grade cable shall be
used.
All MICS cable shall have a LSF oversheath, coloured Orange or White for low voltage and
general services as defined in the Particular Specification and Red for fire alarm wiring.
No conductor less than 1.5mm² cross sectional area shall be used.
Only competent workmen who have received full instruction in the technique involved
shall carry out the installation of MICS cables.
Cables shall be fixed at intervals not exceeding 300mm for straight runs and 150mm from
any set or bend.
Surface mounted cables shall be secured with LSF covered brass or copper saddles to
match the sheathing colour of the cable, and as supplied by the cable manufacturer.
Parallel runs of cable shall be secured with multiple saddles where cables touch. All
saddles and fixings shall be secured in position with round-headed brass screws or brass
nuts and bolts.
Where more than 2 No. MICC cables are run together, they shall be installed on
galvanised cable tray, sized to permit a minimum 25% of additional cables to be installed
and cable shall not be double-banked on tray.
Cable joints will not be permitted.
All accessories used in conjunction with the termination for the connection of cables shall
be purpose-made and a supplied by the cable manufacturer. Standard glands shall be of
the cold seal screw-on pot type. Gland shrouds shall be fitted to all terminations at
surface mounted equipment. Hazardous area type glands shall be included where
required.
Where MICS cables are terminated the conductor tails shall be insulated with the
appropriate size and temperature rating of neoprene sleeving sealed into the gland. This
sleeving shall have appropriate colour identification or markings for phase and neutral
conductors.
Cable gland terminations into distribution boards, switch/socket boxes and accessories
shall be fixed with the appropriate size male brass bush and steel coupler arrangement
fitted between the cable gland and enclosure. Where accessory enclosures are nonmetallic, measures shall be taken to maintain earth continuity by the use of proprietary
earth tail terminations.
Terminations of MICS cables at motor terminal boxes, or other equipment where some
degree of movement is required, shall have a 360° loop formed at the final terminal, the
radius of which shall be suitable to permit belt tensioning or other adjustment. When
possible the cable shall terminate at a fixed connection box with flexible conduit
containing flexible cable as the final connection.
Cable terminations and termination equipment shall comply with BS 6081.
Part 2 – Page 9 of 31
RIDGE
Electrical Specification
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Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
In external locations and other damp situations where glands are screwed into aluminium
alloy fittings, bitumastic paint shall be applied to the junction between gland and fitting,
and to any exposed threads to avoid corrosion.
Ends of cables, which must be left unfixed due to the building construction, must be
coiled and secured to a temporary fixing and not supported solely by the cable. All ends
of cable, which are not permanently sealed by glands, must be sealed by a liberal external
application of sealing compound, held in position by self-adhesive PVC tape. When final
terminations are made a minimum of 300mm of cable must be removed to ensure no
ingressed moisture remains in the terminated end of the mineral insulation.
Where cables pass through walls or in other areas where they may be subject to damage
or abuse, they shall be protected by running in Heavy Gauge PVC conduit, installed to act
as a protective sleeve.
No MICS cable shall be laid in floor screed except with permission, in wiring, of the
Contract Administrator. Under these conditions cable shall be installed in Heavy Gauge
PVC conduit of not less than 4 times the diameter of the cables being installed with no
more than 2 cables in any one conduit run.
All cables shall be tested with a 500 or 1000v insulation resistance meter immediately
after sealing and before connection. They shall be tested again not less than 24 hours
later. Nothing less than a 100MW reading will be accepted.
Should it be necessary to deface building finishes due to the rectification of bad sealing of
cables, or faulty installation, the Main Contractor shall bear the cost of all making good.
The use of FP200 or similar fire rated cables will not be permitted as a substitute for
MICS cable, unless specifically called for in the Particular Specification.
When used for fractional horse power motors, contactor coils, fluorescent lights, then
suitable surge suppressors shall be fitted at the load end of the cable, and test warning
notices fitted at the Distribution Board
2:1:17.0
Duct
Installations
Unless otherwise indicated the Main Contractor will be responsible for excavating all
trenches for underground cables and for providing sand or "pea" gravel for cable bedding
and cover. He will also provide all necessary cable ducts for the conveyance of cables in
and out of buildings and beneath road and path crossings. He shall backfill all trenches
upon completion of the cable works. The Main Contractor shall install warning tape during
this backfilling.
The Main Contractor shall be responsible for ensuring that the facilities provided are
suitable to accept the cable installation. Any doubts as to the suitability of these facilities
shall be addressed to the PM.
Cables shall be laid at the depths given on the drawings, measured from the top of the
cable to finished ground level (using proposed levels and not existing site levels).
The Main Contractor shall provide cable warning and protection in accordance with the
following:
Part 2 – Page 10 of 31
RIDGE
Electrical Specification
Forestry Commission
Client Name :
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
1.
A yellow pre-printed heavy gauge polythene cable warning tape shall be laid
continuously along all electrical cable routes, placed above the cable and positioned
250mm below ground level. The tape shall bear warning indication of the type of
service involved (including multiple runs).
2.
Heavy gauge interlocking cable tiles to BS 2484 laid immediately over the cable, but
separated from it with a 20mm sand bedding, along all routes.
Where ducts enter buildings or terminate above ground, the Main Contractor shall seal the
cables in the ducts by using a non-setting type of sealing compound, or removable split
plug.
Except for road crossings, all external cable routes shall be identified by ground-mounted
markers installed at a maximum of 20m intervals along straight runs and at every change
of direction. The markers shall be mounted flush with the surrounding ground level, and
bear the words 'Electricity Cable' in 3mm indented 25mm high letters, stating cable LV or
HV, if joint present, depth and an inscribed line indicating the direction of the cable run.
Where ducts are provided, the Main Contractor shall provide and install a nylon draw
rope, suitably secured at each open end, throughout the length of each duct, whether the
duct has been utilised for the purposes of the installation or not.
2:1:18.0
PVC/XLPE
Insulated,
Armoured
PVC
or
Sheathed
Cables
Cables of this type shall include the following:
and
LSF
a.
PVC insulated, PVC bedded, single steel wire armoured, PVC sheathed with
stranded copper conductors.
b.
PVC insulated, PVC bedded, aluminium tape armoured, PVC sheathed with
stranded aluminium conductors.
c.
PVC insulated, PVC bedded, aluminium tape armoured, PVC or LSF sheathed with
solid aluminium conductors.
d.
Cross-linked polythene insulated (XLPE), PVC bedded, single steel wire
armoured, PVC sheathed with stranded copper or solid aluminium
conductors.
All cables described in sections a, b and c above shall be constructed in accordance with
BS 6346. Cables described in section d shall be constructed in accordance with BS 5467.
Unless otherwise specified, sub-main cables up to and including 16mm² shall be of
XLPE/SWA/LSF construction. PVC/SWA/PVC may be used where completely buried or
external to the building.
Cables with reduced neutrals shall not be used unless specifically instructed.
All cables shall be rated 600/1000v. Except where other frequencies are requested, all
cables shall be rated for 50 Hz
All cables shall be terminated with brass compression glands of the type recommended by
Part 2 – Page 11 of 31
RIDGE
Electrical Specification
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Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
the cable manufacturers and shall be compatible with the construction of the cable
involved. Serrated tempered zinc steel washers shall be used for all terminations up to
32mm diameter. Where the gland diameter exceeds 32mm a minimum of two heavy
gauge galvanised lock nuts shall be used with the termination. Black PVC gland shrouds
shall be fitted in all instances.
For external work and where the minimum degree of protection required is IP55, then a
brass weatherproof gland assembly shall be used.
Brass earthing plates shall be fitted, the termination onto the equipment metalwork being
formed with brass bolt, serrated washer and nut. A bonding connection shall be made
from this earthing plate directly to the equipment earth terminal.
Cable cores shall be terminated with suitable size lugs, which shall be secured to the cable
core either by soldering or by compressing the lug with a hydraulic compression tool in
accordance with the cable manufacturer's recommendations.
2:1:19.0 Cable
Supports
All surface cables shall be fixed by means of cast aluminium or black nylon cable cleats
selected to suit the size and weight of the cables involved. As an alternative and where
multiple parallel runs of cables occur, cable trays may be used with cable fixings made
with cable cleats, PVC coated fixing saddles or PVC cable ties. The appropriate spacing
between cables shall be maintained. Proprietary cable cleats, as described above, only
shall be used for cables that are either (a) run vertically, (b) suspended from cable tray,
or (c) exceed 20mm diameter.
Cable cleats shall be of a size such that they can be tightened down to grip the cable
without exerting undue pressure or strain. For vertical cables two bolt cable cleats shall
be used to grip the cable firmly enough to prevent slipping.
Cable supports shall be installed at intervals not greater than those recommended by the
cable manufacturers in order to prevent sagging. Generally, the following fixing
dimensions shall be adhered to, but additional support shall be installed whenever
directed by the Contract Administrator in order to maintain a secure and straight run, or
where specifically required to comply with the IEE Regulations.
Cable Type
Size
Maximum Spacing (mm)
Horizontal
Vertical
PVC/SWA/PVC
600/1000v
2 and 4 core
-up to 2.5mm²
350
450
-4mm² and 6mm²
400
550
-between 10mm²
and 70mm²
450
600
-95mm² and above
600
750
-up to 6.0mm²
900
1200
-10mm² and 16mm²
1500
2000
Mineral Insulated
(heavy duty)
2 and 4 core
Part 2 – Page 12 of 31
RIDGE
Electrical Specification
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Section 6
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Project Nr :
141200
Electrical Workmanship
-25mm² and above
1800
2000
All cable runs shall be made vertically and/or horizontally, with bending radii as previously
specified. No diagonal runs will be permitted. Poorly installed cables shall be re-dressed to
the satisfaction of the Contract Administrator.
2:1:20.0
Underground
Cables
Unless otherwise indicated the Main Contractor will be responsible for excavating all
trenches for underground cables and for providing sand or "pea" gravel for cable bedding
and cover. He will also provide all necessary cable ducts for the conveyance of cables in
and out of buildings and beneath road and path crossings. He will backfill all trenches
upon completion of the cable works and the Main Contractor shall install warning tape
during this backfilling.
The Main Contractor shall be responsible for ensuring that the facilities provided are
suitable to accept the cable installation. Any doubts as to the suitability of these facilities
shall be addressed to the Contract Administrator.
Cables shall be laid at the following minimum depths, measured from the top of the cable
to finished ground level.
Low Voltage Cables
-
450mm
High Voltage Cables
-
900mm
Low Voltage and Extra Low Voltage Cables
-
500mm spaced 300mm
min from HV cables
Telephone, Communications and Data Cables
-
500mm spaced 300mm
min from mains voltage
cables
The Main Contractor shall provide cable warning and protection in accordance with the
following:
1.
A yellow pre-printed heavy gauge polythene cable warning tape shall be laid
continuously along all cable routes, placed above the cable and positioned 300mm
below ground level. The tape shall bear warning indication of the type of service
involved (including multiple runs).
2.
Pre-cast concrete interlocking cable tiles to BS 2484 or plastic interlocking tles laid
immediately over the cable, but separated from it with a 20mm sand bedding, along
all routes in planted areas subject to digging or general garden maintenance or in
other locations if specifically requested on the drawings or elsewhere in this
Specification.
Where ducts enter buildings or terminate above ground, the Main Contractor shall seal the
cables in the ducts by using a non-setting type of sealing compound, or removable split
plug.
All external cable routes shall be identified by ground-mounted markers installed at a
maximum of 20m intervals along straight runs and at every change of direction. The
Part 2 – Page 13 of 31
RIDGE
Electrical Specification
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Client Name :
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
markers shall be mounted flush with the surrounding ground level, and bear the words
'Electricity Cable' in 3mm indented 25mm high letters, stating cable LV or HV, if joint
present, depth and an inscribed line indicating the direction of the cable run.
Where ducts are provided for the electrical installation, the Main Contractor shall provide
and install a nylon draw rope, suitably secured at each open end, throughout the length
of each duct, whether the duct has been utilised for the purposes of the installation or
not.
2:1:21.0
Protection
Cables
of
In all exposed positions where cables rise from the ground or emerge through walls or
floors and wherever they are liable to damage, they shall be protected by metallic sleeves
or sheet steel guards to a height of 2000mm above FFL.
Where cables are liable to rub against sharp edges and corners, rubber or nylon
protection channel/grommet strip shall be provided to prevent abrasion of the cable
sheath.
2:1:22.0
Conduit
Systems
Fixed
Steel Conduits - In dry internal areas heavy gauge (black enamel) steel with welded
seams and screwed joints to BS 4568 Part 1, Class 2.
In external and damp internal areas, cavities of external walls, etc., solid drawn,
galvanised inside and out, with watertight joints to BS 4568, Part 1, Class 4.
All conduits shall be heavy gauge, screwed and welded steel having a black enamelled
finish unless specified otherwise. Conduits used in plant rooms, garages, external to the
building, in unheated tunnels or ducts and other areas exposed to the elements, shall be
galvanised.
Where conduits are installed in areas not being made watertight for a considerable period,
for whatever reason, then galvanised conduit work shall be installed. The Main Contractor
should agree such instances with the Main Contractor during programme scheduling;
rusting BE conduit will not be accepted. Conduits shall be mechanically and electrically
continuous throughout. They shall be watertight as far as possible with provision made
for drainage of condensed moisture where necessary.
Where a large number of circuits run in the same location the Main Contractor may, if so
required and agreed with the Contract Administrator, use a common cable trunking to
reduce the number of conduits installed. All trunking shall comply fully with the terms of
this Specification.
Generally, wiring serving circuits of different use, e.g. lighting and power, shall be run in
separate conduits with only short lengths or lightly loaded conduits being used for both
services.
Where conduits are installed for use by others they shall have a draw wire installed
throughout their length and adequate pull in boxes to allow future cables to be installed.
Where these cables are for telephone or extra low voltage use and of light duty, additional
draw boxes may be necessary. It will be the Main Contractor's responsibility to ensure
adequate draw in points are installed during installation and if it is found necessary for
him to return to site to install additional points this will be done at no extra cost. All draw
boxes shall be provided with a proprietary lid secured to the box with 1 No. of 2 No.
Part 2 – Page 14 of 31
RIDGE
Electrical Specification
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Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
screws, prior to specialist wiring being installed, to allow the specialist contractor to fully
secure the lids on completion of wiring. The lids of draw boxes ultimately remain the
responsibility of the Main Contractor.
Bends shall be made cold without flattening or distortion of the cross section of the
conduit. Sets shall be made only within the prescribed limits of the IEE Regulations. Solid
or machined bends, inspection elbows or tee pieces shall not be permitted.
Care shall be taken during the whole of the installation of conduits to remove any burrs or
sharp edges that may have been created. Any cables found to have score marks on them
after being drawn into the conduits may result in the whole of the conduit and cable run
to be made good.
Where the protective coating of the conduit has been removed during installation, this
shall be made good immediately to prevent rusting. This shall be achieved by the
application of 1 No. coat of red oxide paint for flushed in black enamelled conduits, 1 No.
coat of red oxide paint followed by 2 No. coats of black ‘Hammerite’ paint for surface
mounted black enamelled conduits and 2 No. coats of ‘Galvafroid’ paint for flushed in or
surface mounted galvanised conduits. Any costs involved in removing rust stains caused
by rusty conduits will be borne by the Main Contractor.
Concealed conduits shall be erected in chases and fixed with wrought iron (galvanised or
black enamelled as necessary) crampets at a distance of 300mm from terminations and
bends and a maximum of 1750mm intervals ensuring no mechanical strain on the conduit
and that no protrusions inhibit the finish of the building fabric to maintain a finish depth of
10mm. No draw box shall be concealed within wall finishes.
Where conduits are surface mounted in normally visible situations, spacer bar saddles
shall be used.
Where two or more conduits are run side by side, saddles shall be staggered to minimise
the spacing between conduits. Alternatively multiple saddles may be employed.
Saddles shall be fixed at maximum intervals of 1500mm for 20mm, 1800mm for 25mm
diameter conduits and 2000mm for 32mm diameter conduits with an emphasis on
equidistance. Where a multitude of sizes of conduit are installed, in close parallel runs, the
intervals of saddle fixings shall be determined by the smallest conduit present. The
saddles shall also be fixed at a distance no greater than 300mm on either side of
terminations, bends and sets, and 300mm from floors or ceilings where conduits rise or
drop between floors.
Where conduits are fixed on floor slabs prior to laying of insulation and/or screed, care
shall be taken to ensure that conduits only cross where one conduit may be set to pass
below the others. Conduits shall be fixed to floor slabs with wrought iron (galvanised or
black enamelled as necessary) crampets at a distance of 300mm from terminations and
bends and a maximum of 1750mm intervals ensuring no mechanical strain on the conduit
and that the sum angle of all bends between draw boxes does not exceed 180o with no
single bend exceeding 90o. No draw boxes shall be concealed beneath floor finishes.
Conduits cast into in-situ concrete structures shall be securely fixed to the reinforcing to
prevent damage or movement during concrete pouring operations. The Main Contractor
Part 2 – Page 15 of 31
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Electrical Specification
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Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
shall have a representative in attendance at all times when concrete is being poured to
ensure that the conduit installation is not affected, paying particular attention to the
positioning of the installation and the integrity of conduit entries.
Conduit connections to equipment or conduit boxes shall be made with an internal male
brass bush, serrated washer and coupling. Spout entry boxes shall have conduits screwed
up solidly and secured by means of a locknut. All conduit boxes and fittings shall be
screwed up tight. All unused conduit entries shall be plugged to prevent the ingress of
moisture and dust.
Malleable conduit fittings shall be used throughout and shall be compatible with the
conduit tube, i.e. galvanised. Galvanised conduit boxes and fittings in damp situations
shall have gasketted lids to prevent ingress of moisture. All conduit boxes shall
incorporate an earthing lug to accept the appropriate protective conductor.
All conduit boxes shall be fixed using pan head or round head screws, suitably rust proof.
Countersunk wood screws shall not be used.
All sections of the conduit installation shall be complete before any cables are drawn
through.
Conduit outlets and boxes shall be suitably plugged before any plasterwork takes place
and the interiors of all boxes cleaned before any cables are installed.
Surface conduits crossing expansion joints shall employ a snaked flexible conduit with
access boxes placed either side of the expansion joint. Conduits in concrete across
expansion joints shall be brought to the surface with a flexible transition.
Plastic conduit shall be installed in accordance with manufacturers recommendations and
in compliance with BS 7671.
2:1:23.0
Flexible
Conduits
Provide for final connections to machines etc., to BS 731 Part 1, Type B flexible metallic
tubing sheathed with PVC, with brass adaptors fixed at both ends with external PVC
insulated copper earth wire, connected to terminals at both ends.
All Insulated Conduit - to be as specified for steel conduit except as manufacturers
detailed instructions with compatible accessories, boxes, etc., and with semi-permanent
mastic joints in corrosive or damp situations.
Where all insulated conduits are to be installed, the embossed, printed text shall not be
installed in view.
Where flexible conduit is specified to form the final connection between the fixed
installation and a motor, or other apparatus where some degree of movement/vibration is
required, it shall be of the flexible metallic type having a black PVC waterproof sheath,
and terminated at each end with the corresponding manufacturer's earthed gland
connections.
The length of flexible conduit used for each final connection shall be kept as short as
possible and shall in no situation exceed 1000mm.
Part 2 – Page 16 of 31
RIDGE
Electrical Specification
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Project Nr :
141200
Electrical Workmanship
A separate earth continuity conductor, of the minimum size specified according to the
circuit conductors, and having PVC green/yellow insulation, shall be run through the
flexible conduit and bonded onto the equipment and conduit metalwork at each end. This
conductor shall be separate from any of the circuit protective conductors contained within.
2:1:24.0 Wiring
of Conduits
Conduits shall be swabbed through and thoroughly dried before the installation of cables.
No wiring shall be carried out before all conduit work has been completed and tested for
earth continuity. The Main Contractor shall be responsible for removing all dirt and
obstructions in conduits prior to wiring.
Wiring in conduits shall comply strictly with the BS 7671.
2:1:25.0
Trunking
Installation
Cable trunking shall be manufactured to comply with BS 4678 and be simple rectangular
constructed from rust proofed mild steel sheet finished stove enamel, or galvanised as
specified, 18 gauge for longest side up to 100mm 16 gauge up to 150mm and 14 gauge
up to 230mm, made in continuous lengths up to 3600mm, of section of the lipped type
with flange or lip along whole of the open side with continuous lid or cover made to same
quality and length arranged to overlap trunking flange or lip and be securely fixed thereto.
Self-tapping screws will not be acceptable.
The manufacturer's bends, connectors and fittings, including earth links, shall be used on
all trunking runs. All screw heads, cut edges and other protrusions within the trunking
shall be checked, and appropriate action taken, to ensure that no abrasion of cables can
occur. Similarly, any raw edges of metalwork present in the trunking, where it is intended
for cables to pass through, shall be trimmed with small section plastic edging
channel/grommet. All site-cut edges shall be painted with ‘Galvafroid’ paint.
Trunking lids having brass captive turnbuckle fixings shall be installed.
Trunking shall be fixed at intervals no greater than those set out in the IEE Regulations or
recommended by the manufacturer and under no circumstances will sagging be
permitted. Fixings shall also be made through all proprietary bends and within 300mm of
any change of direction in the trunking run. Any trunking having a base width of 75mm
and above shall be secured with 2 No. screws at each fixing position when support
directly to the building fabric.
Where trunking is required to carry wiring serving circuits of different category it shall be
multi-compartment (complete with bridging sections) to segregate cables. Segregation of
ELV and LV cables, data/communication services and fire alarm circuitry shall be
maintained at all times.
Where trunking bridging sections are used these should be so sized to provide ‘full
capacity’ wiring facilities similar to the main trunking runs. Reduced capacity bridging
sections may only be used on lightly loaded runs and with the express permission, in
writing, of the Contract Administrator.
Trunking manufacturers proprietary cable retainers shall be used on all trunking runs
except where installed ‘lid up’.
Where trunking passes through walls, ceilings or floors, the hole shall be made good to
the full thickness of the surrounding structure and to the equivalent fire rating of the
Part 2 – Page 17 of 31
RIDGE
Electrical Specification
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Section 6
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Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
material penetrated. In addition fire-resisting barriers shall be provided within the
trunking at the position where it passes through all fire-rated structures.
Vertical trunking runs exceeding 5m shall have plastic coated "pin" racks installed at
maximum 5m intervals to support circuit cables.
Where multiple circuits are installed within a trunking run, cables in each individual circuit
shall be grouped together (including neutral and earth conductors) with numbered or
coloured PVC tape or sleeves.
All trunking runs shall be electrically and mechanically continuous throughout their length
and bonded to the building earthing system.
Where trunking runs across building settlement or expansion joints a trunking joint, with
slotted fixing holes to allow both vertical and/or horizontal links shall be provided across
this joint. Earth continuity shall be effected by the provision of a braided copper tape
(minimum size 15mm x 2mm) and shall be long enough to allow for the maximum
movement of the trunking. The braided ends shall be folded, soldered and suitably
secured to the solid ends of trunking either side of the expansion/settlement joint.
All conduits connected to a trunking shall be fitted using a brass male brush, serrated
washer and flanged coupling.
Cable shall be installed so that the capacity does not exceed the values required by IEE
Regulations, or any limiting capacity stated elsewhere.
Under no circumstances shall lighting "Suspension Trunking" be used as main
power/lighting distribution trunking.
2:1:26.0 Cable
Basket/Tray
Installation
Unless otherwise specified cable tray shall be fabricated from a minimum of 16 SWG
perforated, hot dipped, galvanised steel. Tray should be of the Heavy Duty pattern with
return flanges and a minimum flange depth of 25mm.
A minimum tray width of 50mm shall be used unless specified otherwise.
All accessories shall be purpose made by the tray manufacturer in the same material as
the main tray runs. "Special" sections shall only be used when authorised in writing by
the Contract Administrator.
Joints in tray runs shall be made using straight or cranked couplers, with fish plates
installed where recommended by the manufacturers for the size of tray and weight of
cables being installed. All bends, internal and external tees, intersections, risers etc. shall
be angled to allow the specified minimum bending radius of the cables to be maintained.
Earth strips (copper-tinned) are to be provided at each joint.
Where tray edges are cut all raw edges shall be turned away from the cables or protected
to ensure no abrasion of cable sheath can occur. All site-cut edges shall be painted with
‘Galvafroid’ paint.
Suspension of tray runs shall be at a maximum of 1500mm intervals with additional
fixings/supports provided for all bends and within 300mm of all bends, tees and
Part 2 – Page 18 of 31
RIDGE
Electrical Specification
Client Name :
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Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
intersections.
Suspension shall also be provided to ensure the manufacturers' stated maximum mid
point flange deflections (allowing for an additional allowance of 25% cables by weight)
are not exceeded. Support brackets shall generally consist of "Unistrut" or equal channel
supported via 6mm screwed drop rods with nut, washer, and lock nut from the building
structure.
Where trays pass through walls, ceilings or floors, the hole shall be made good to the full
thickness of the surrounding structure and to the equivalent fire rating of the material
penetrated.
Cables shall be fixed to tray using PVC cable ties at a maximum of 2000mm centre for
horizontal runs or 1000mm for vertical runs.
Cables shall be installed on tray in a single layer, or in trefoil formation for single core 3
phase circuits except were specified otherwise, leaving 25% of the tray width as spare for
future installation.
All cable tray runs shall be electrically and mechanically continuous throughout their
length and bonded to the building earthing system.
Where cable tray is required to run above main switch panels, taking multiple runs of submain cables, cable ladder can be used in place of tray to allow for easy access of cables
from below. Generally, the installation clauses above for trays shall apply to the ladder
installation but consideration may have to be given to support ladder runs from below if
other means of support of adequate strength is not available.
Ladder runs should be taken to the exit point of plant rooms before the change back to
tray. This joint should be formed by overlapping tray and ladder runs. For earth bonding
both tray and ladder installations should be deemed to be one.
Where cable ladder is required in other locations than switchroom it shall be as specified
elsewhere.
2:1:27.0
Earthing
The Main Contractor shall be responsible for the installation of all earthing systems
specified in this document, shown on the sub-contract drawings and required to comply
with the IEE Regulations in order to ensure protection for safety and protection against
electrical shock.
The earthing system shall include (as required):
Earth electrode system or main earth terminal
REC earth electrode system
Main earthing bar with test link
Protective conductor installations
Main equipotential bonding of other services
High Integrity Earthing
Clean earths
Supplementary equipotential bonding of exposed conductive parts
Supplementary equipotential bonding of extraneous conductive parts
Part 2 – Page 19 of 31
RIDGE
Electrical Specification
Forestry Commission
Client Name :
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
Bonding to lightning protection system
Bonding to steelwork framed building
Bonding to the lift shaft steelwork
2:1:28.0 Earth
Electrode
System
Details of the system are contained in the Particular Technical Clauses. The Main
Contractor shall test the system upon completion and well in advance of the contract
completion date, and advise the Contract Administrator of the resistance obtained.
Should any additional electrodes or electrode sections be required in order to reduce a
high resistance to an acceptable value, the Contract Administrator will issue any necessary
instructions.
2:1:29.0
Earth Bar
Where a main earth bar is specified, this shall be formed from 75mm x 5mm tinned
copper bar of a length to adequately accommodate all protective and bonding conductors
specified. The earth bar shall incorporate a bolted link formed in the same material, to
allow disconnection of the main incoming earth conductor. The whole earth bar
arrangement shall be mounted on insulated supports.
Main
All earth cables terminating on the earth bar shall be labelled, as specified elsewhere, to
indicate cable size and function.
2:1:30.0
Protective
Conductors
All sub-main cables and sub-circuit cable systems shall incorporate protective conductors,
either as an integral part of the cable construction or as a separate conductor run with
circuit phase and neutral conductors.
Cables having steel wire armouring shall, unless otherwise specified, use the armour as
the protective conductor. Bonding at each termination shall be ensured by earthed glands
and secondary bonding onto the equipment casing by means of bolted earth tags. A
bonding conductor shall also be installed from the earthed gland to the equipment earth
bar or terminal.
Where additional protective conductors are installed, these shall be run in parallel with
and clipped to the associated supply cable, and terminated onto the bolted earth tags and
terminals specified above.
All sub-circuit wiring supplies shall incorporate a copper protective conductor the CSA of
which shall be calculated according to the IEE Regulations.
These protective conductors shall be run with the circuit conductors in the same trunking
and conduit installation. They shall have a green/yellow PVC insulation.
Sub-circuit protective conductors shall terminate onto the earth terminals in each conduit
and accessory box installed as part of the trunking and conduit system for each
appropriate sub-circuit.
Where circuit conductors are run as a ring circuit, the protective conductor shall also form
a ring.
2:1:31.0
Equipotential
Bonding
of
Other
Service
Equipotential bonding shall be made to all incoming gas, oil and water mains as near as
possible to their entry position. This bonding shall be carried out with green/yellow
copper conductors sized in accordance with Table 54H of BS 7671, or as requested by the
Supply Authority. Separate conductors shall be run to each service from the main earth
Part 2 – Page 20 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
mains
Electrical Workmanship
bar.
Warning notices shall be fitted at the termination points in accordance with BS 7671.
2:1:32.0
Equipotential
Bonding
of
Exposed
Conductive
Parts
Supplementary bonding of exposed conductive parts of all electrical equipment shall be
made by means of green/yellow PVC insulated copper conductors of a size at least equal
to the phase conductor size feeding the item of equipment involved, subject to a
minimum size of 2.5mm² cross sectional area, if mechanically protected and 4.0mm² if no
protection is provided.
All bonding conductors shall be mechanically protected and run within equipment
enclosures, trunking or conduit. Terminations at equipment shall be formed with either
purpose made brass terminals, or brass nuts, bolts and serrated washers.
2:1:33.0
Equipotential
Bonding
of
Extraneous
Conductive
Parts
The Main Contractor shall be responsible for bonding to earth all conductive parts not
forming part of the Electrical Installation but which are liable to introduce a potential and
are not electrically connected to the main equipotential bonding system by permanent and
reliable metal to metal joints of negligible impedance, and have not been covered by
preceding clauses.
Accessible structural steel work shall be bonded directly to the main earth bar, and/or the
earth bar contained in an adjacent switchboard or distribution board by a green/yellow
PVC insulated copper conductor having a cross sectional area at least half that of the
phase conductor feeding the switchboard or distribution board, subject to a minimum size
of 6mm². In addition supplementary bonding shall be installed to steel work from the
protective conductor at equipment mounted adjacent to accessible structural steel work.
All ventilation ducts shall be bonded at their source where they connect onto air handling
unit chambers, fan enclosures, etc. this bonding being carried out in a similar manner that
described for structural steel work. Ducting will be considered as being continuous where
sections are connected by direct bolted flanges, screwed or riveted lap-joints. Where
flexible insulated sections are inserted in duct runs, or flange connections with an
insulating gasket, then a bonding conductor shall be installed to link the two sections.
This conductor shall be the same size as the bonding conductor at the ductwork source.
Main pipework for heating, cold water, chilled water, condenser water systems, etc., shall
be bonded at their source where they connect onto boilers, calorifiers, chillers and other
main plant items. This bonding shall be carried out in a similar manner to that described
for structural steel work.
Pipework will be considered to be continuous where connections are made by means of
welding, soldering or metal-to-metal compression joints. Screwed joints using PTFE tape
or hemp and sealant are not deemed to be electrically continuous until verified by testing.
Where these latter joints are used and have been found not to be electrically continuous,
then sections of pipework and equipment (valves and expansion bellows), etc.,
simultaneously accessible with exposed conductive parts of other extraneous conductive
parts shall have supplementary bonding installed, including flexible joints, bellows and
hoses.
Supplementary bonding to extraneous conductive parts shall be installed from adjacent
Part 2 – Page 21 of 31
RIDGE
Electrical Specification
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Forestry Commission
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Project Title :
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Project Nr :
141200
Electrical Workmanship
pipework, or from adjacent electrical equipment protective conductors when considered
necessary in order to ensure the integrity of the IEE Regulations. Extraneous conductive
parts may include the metalwork of baths, sinks, tanks, compressed air outlets, taps,
radiators, ceiling grids and other items mentioned in previous clauses and listed in these
documents.
Supplementary bonding shall be taken from luminaries fixed into or onto a suspended
ceiling and connections made to the two main suspension bars one either side of the
luminaire.
Where supplementary bonding is run in plastered or rendered wall finishes it shall be
conveyed in conduit which shall terminate in a small round BESA box immediately
adjacent to or, where practical behind the item of plant or equipment to be bonded. The
conductor shall be made off into an earth terminal within this box. Final connection shall
be made with an appropriate sized earth conductor, passing through a bush in the lid of
the BESA box and terminating on to the equipment with a suitable connection. The
connection shall be made as short and as neat as possible but may incorporate a number
of coils in order to provide an amount of flexibility.
Where supplementary bonding conductors run on the surface and are required to be fixed
to "fair face" wall finishes for more than 600 mm length of run the conductor shall also be
installed in conduit installed for surface finish. Where the conductors enter or leave such
conduit a female brass bush shall be used.
All connections of supplementary bonding, warning notices as described in the IEE
Regulations shall be fixed. Where it is not practical to fix this notice on plant or
equipment where the bonding terminates, it may be fixed immediately adjacent to the
bonding conductor at the wall mounted BESA box.
2:1:34.0
General
Bonding
Requirements
In all cases it shall be the responsibility of the Main Contractor to ensure the final
installation complies with the earthing requirements as defined by the IEE Regulations,
the method of bonding where required being determined by actual site conditions and
installations. Adequate provision for bonding shall therefore be included at the tender
stage of a project.
2:1:35.0
General Fixings
for Equipment
The Main Contractor shall be responsible for securely fixing all items of electrical
equipment by one or more of the methods described below:
Plugged fixings using "Rawlplug" or equal materials shall be used for lightweight items of
equipment. Screw fixing used with this type of plug material shall be not less than 32 mm
x No 8.
Expanding bolt fixings using "Rawlbolt" or equal fittings shall be used for fixing heavy
plant, distribution boards, panels, etc., to solid structures. Bolted fixings shall be inserted
to their full length. Where plaster or tile finishes are present, then the bolts shall be
inserted past these finishes and into the main structure.
Where necessary heavy wall mounted equipment shall be erected on a fixing channel
framework, which in turn shall be securely fixed to the wall structure. Details of support
frames shall be submitted to the Contract Administrator for comment before manufacture
commences. All metalwork shall be rust free and receive at least one coat of primer and
Part 2 – Page 22 of 31
RIDGE
Electrical Specification
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Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
two finishing coats of aluminium paint.
Fixings required directly to structural steel work or pre-cast concrete beams shall only be
made after prior approval from the Contract Administrator has been received. Generally,
fixings for brackets, etc., shall not be less than 5mm diameter. Drilling of structural steel
work shall not be permitted except with the written authority of the Contract
Administrator. Shot fired fixings shall not be employed.
Where equipment requires rag-bolt or other grouted fixings, all details shall be given to
the Main Contractor at an early stage in the contract to ensure that the correct holes are
left in foundations for fixing purposes.
2:1:36.0 Main
Switch Panels,
Isolators
and
Fused
Switchgear
All isolators and switchgear, whether mounted in cubicle type switch panels or separately,
shall conform to the requirements of BS EN 60947-3 for air break switches and BS EN
60439-1 for factory built assemblies of switchgear and control gear. They shall be totally
enclosed in solidly constructed mild steel cases of clean external appearance with securely
hinged and gasketted access doors having provision for padlocking. Padlocks are not
required unless specified.
All switchgear shall be as detailed elsewhere in this specification and unless specified
otherwise shall be of the same manufacture, type and range throughout.
Where switch panels are specified the Main Contractor shall provide to the Contract
Administrator the manufacturer's layout drawings, circuit/wiring diagrams and label
schedule for comment before manufacture commences.
Switchpanels shall be constructed to take a minimum fault level of 43kA at 400 volts for 1
second unless specified otherwise. The class of protection (to BS EN 60439-1) being a
minimum of Form X (X being indicated in the particular part of this specification).
A copper earth bus bar shall be run internally the full length of the switch panel and each
section of the panel shall be bonded to it. Double CSA neutrals shall be employed.
Where "industrial" style switch panels are required, comprising loose items of equipment,
these shall be mounted on a common galvanised fixing channel frame, or where site
conditions allow, direct to a structural wall. Equipment layout, including cable tail
interconnection details shall be submitted to the Contract Administrator for his comment
prior to installation.
It will be the Main Contractor's responsibility to ensure it is possible to fit all equipment or
switch panels within the space allocated prior to the start of installation. While allowing
space for future additions where specified.
Interconnections between items of freestanding switchgear and bus bar assemblies shall
be made wherever possible using solid copper bar links, supplied by the equipment
manufacturer for this purpose.
Cable extension boxes shall be provided where required preventing stress to sub-main
cable terminations. Provision of these boxes shall be the Main Contractor's responsibility
included within his tender.
Part 2 – Page 23 of 31
RIDGE
Electrical Specification
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Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
Distribution boards shall be manufactured to BS 5846 and shall consist of substantial
sheet steel cases complete with hinged doors with latching devises. Neoprene gaskets
shall be fitted to doors to prevent the ingress of dust and moisture. Distribution boards
shall be provided with the manufacturers’ proprietary locking mechanisms.
Distribution boards shall contain protective devices of the following types:
1.
HRC cartridge fuses, complying with BS88, Part 2.
2.
Moulded case circuit breakers (MCCB’s) complying with BS EN 60947-2.
3.
Miniature circuit breakers (MCB’s) complying with BS EN 60898.
The operating characteristics of breakers shall generally be as follows, unless
stated otherwise within the specification.
Type B Control circuits, resistive loads only with no inrush or switching current
Type B Lighting (tungsten), resistive heating loads
Type C General power loads, ring mains etc., lighting (discharge and
fluorescent), "off- load" motor starting, i.e. reduced start to produce maximum
2x running current.
Type D "on-load" or direct on line motor starting, welding equipment etc., long
duration surges
4.
Residual current circuit breakers (RCCB’s) complying with BS EN 60898.
Also termed residual current device (RCD).
5.
Residual current breaker with overload protection, otherwise termed as
combined RCD/MCB or RCBO.
Neutral bars and earth (protective conductor) bars contained in distribution boards shall
have sufficient terminals to enable all available circuit ways (single phase) to be
terminated separately and without bunching neutral or earth conductors. Connections to
neutral and earth bars shall be made in circuit sequence and all conductors shall be
numbered to correspond with the circuit phase/way number.
Distribution boards situated remotely from the main control switch, shall incorporate an
"on-load" switch disconnector, rated to a category of utilisation AC23, mounted either
integrally or in a separate enclosure immediately below the distribution board.
Precise details of all distribution boards, protective devices and circuits are contained in
the specification schedules and drawings.
Each distribution board shall contain, or have permanently fixed beside it, an A4 circuit
schedule indicating the information appertaining to the characteristics of each circuit. A
typical schedule format is included within the appendices of this specification. The
schedule shall be protected by a clear plastic envelope, a clear Perspex screw fixed sheet,
encapsulated frame or be laminated.
Each distribution board shall have a screw fixed identification label, of white background
with black lettering, engraved traffolyte, bearing the reference number indicated on the
design schematic drawings and the phase identity. The lettering shall be not less than
Part 2 – Page 24 of 31
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Electrical Specification
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Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
10mm high capitals.
A warning label shall also be displayed where sensitive electronic devices, semi-conductor,
high frequency fluorescent control gear is connected to final circuits which may suffer
damage during cable insulation resistance or earth fault loop impedance tests.
The same warning shall also be included on the relevant circuit schedules and in the O&M
Manuals.
2:1:37.0 Socket
Outlets
and
Fused
Connection
Units
Unless specified otherwise, socket outlets for general small power facilities shall be 3-pin
(2 pole and earth), 13 Amp, shuttered, switch socket outlets conforming to BS 1363.
They shall be of the type and manufacture specified.
Connection units shall incorporate a single pole cartridge fuse link complying with BS
1362. Double pole switches, indicator lights and flexible cord outlets shall be incorporated
as specified on the layout drawings. 3, 5, or 13 Amp fuses shall be fitted as dictated by
the equipment loading.
Wiring to socket outlets and connection units shall be carried out on ring or radial circuits
as detailed in the circuit schedules. No spur connections shall be taken off ring circuits
without the permission of the Contract Administrator.
All socket outlets and connection units shall have their earth terminal connected to the
outlet box earth terminal by a protective conductor of the same cross sectional area as
the circuit conductors.
All accessory outlet boxes shall be 35mm deep.
2:1:38.0
Lighting
General Circuit
Wiring
Unless otherwise specified, the lighting sub-circuit wiring shall be carried out in LSF
insulated copper cables conveyed in conduit and/or trunking systems. The layout
drawings show all circuit references which, when cross referenced with the distribution
board schedules, detail the cable size, protective device rating, typical circuit loading and
description.
Layout drawings indicate switching circuits, switch locations and types which shall be
rigidly complied with. All circuit references shall be strictly adhered to.
All lighting switches shall be wired into the phase conductor of the lighting circuit. Where
3-phase switching is specified, the lighting switch bank shall be 400 volt rated, fitted with
phase barriers and incorporating a warning label within. Three phase contactor controlled
circuits shall have the switch feed connected onto the specific phase detailed on the
layout drawing. A separate neutral shall be installed for each phase of a 3 phase lighting
circuit.
A green/yellow PVC insulated, copper protective conductor shall be installed for every
lighting circuit, irrespective of the system of installation. The size shall be the same as the
phase conductor(s) specified, or as calculated in accordance with the IEE Regulations.
Lighting circuits shall be wired to suit the associated cable installation method.
Where luminaires are surface mounted or fixed flush to a concealed conduit system,
Part 2 – Page 25 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
connections to luminaires shall be made in the ceiling box by means or porcelain or highgrade melamine, fully shrouded, brass screwed connector blocks. No connectors will be
permitted in switch boxes. Where directly wired and connected, all cables entering the
luminaire shall be protected by heat resisting sleeving applied to their full length within
the luminaire.
Where luminaires are surface mounted by suspension chains or mounted in suspended
ceilings, connections shall be made by 3-core heat resistant flexible cord and 3-contact
plug-in ceiling roses. Where emergency lighting is incorporated within a luminaire,
connections shall be via a 4 contact plug-in ceiling rose and 4 core heat resistant flexible
cord to provide a separate live feed to the battery/inverter pack provided this is sited to
avoid unauthorised interference. Alternatively, a label shall be applied to the plug cover
stating: - ‘Emergency Lighting - Do Not Remove’.
All lighting point boxes and switch boxes shall incorporate a fixed brass earth terminal
which shall be used for the termination of the circuit protective conductor and the switch
or luminaire earth bonding conductor.
Flexible cord connections to high temperature luminaires shall be carried out in 150°C
rubber or glass braided cable.
2:1:39.0
Luminaire
Fixings
General details for suspension and fixings of luminaires are given below. Any specific
detail is shown on the layout drawings or specified in the Particular Specification.
Suspended Luminaires
Suspended fluorescent luminaires shall have two proprietary suspensions as supplied by
the manufacturer. Wiring shall be conveyed internally in the first instance. A flexible cord
shall be run down one suspension and wired from an adjacent ceiling rose. The flexible
cord shall be unobtrusively attached to the suspension.
Surface Luminaires
All surface luminaires shall be fixed directly to the lighting point ceiling box. Heavy
luminaries shall be given additional fixings to ensure that the weight is adequately
supported in accordance with the manufacturer's directions. Fluorescent luminaires shall
have two fixings provided at the standard fixing centres. One fixing shall be the ceiling
box through with the final wiring connection shall be made, the other shall be a blank
ceiling box. Through wiring of final circuit conductors to other luminaires will not be
permitted.
Recessed Luminaires
Generally, suspended ceilings will not be permitted to carry the weight of fluorescent or
other luminaires unless specific approval has been given and detailed on the layout
drawings and approved by the Contract Administrator.
Recessed fluorescent luminaires, (including continuously mounted luminaries), shall be
supported on 6mm screwed rod drops fixing to the structural soffit and of sufficient length
to allow the luminaire to line up with the final ceiling level. All rod suspensions shall be
Part 2 – Page 26 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
provided with serrated washers and lock nuts at all fixing positions to prevent nuts
working loose due to vibration.
Where approval is given to suspend luminaires from the ceiling structure the Main
Contractor shall ensure adequate suspension is available adjacent to fittings and that
suspension is installed in such a way to allow the luminaire to be installed and adjacent
ceiling tiles removed. All such liaison and obtaining of details shall take place via the Main
Contractor.
2:1:40.0
Luminaires
All luminaries shall be supplied, assembled where necessary, erected and connected by
the Main Contractor, all in accordance with the layout drawings and as specified in the
schedule of luminaires.
The whole of the metalwork of the luminaire shall be earthed by a green/yellow PVC
insulated copper conductor connected between the earth terminal in the ceiling conduit
box and the luminaire earth thus forming the final connection of the circuit protective
conduction. Where connections are by plug-in ceiling roses the protective conductor shall
be equally connected.
Where pendant drops are installed, break rings shall be fitted to cover the joint between
the ceiling rose and conduit box.
No diffusers, glassware, louvres, etc., shall be fitted until the building works are
"practically complete" and free from dust. The Main Contractor shall be responsible for
the replacement of all broken or damaged parts of the luminaires until such time as
handover of the affected area(s) has been accepted. Installation warranties shall remain
as detailed in the contract preliminaries.
The Main Contractor shall ensure that all flexible cables entering luminaires are both heat
resistant and securely held by a retaining device.
2:1:41.0 Lamps
and
Lamp
Holders
All lamps shall be supplied and fitted by the Main Contractor upon completion of the
installation. Any lamps which have been used for lighting the building during the
construction period shall be removed and new lamps fitted. All lamps shall be working at
Practical Completion.
Fluorescent and discharge lamps shall be of the type and colour specified in the schedule
of luminaires, and supplied in one consignment from the manufacturer.
2:1:42.0 Wiring
for Mechanical
Services
Provide all power and such control wiring as specifically detailed for the Mechanical
Engineering Services. Control wiring not specifically detailed will be installed by
mechanical services installer. The extent of the work to be:
Electric power wiring, conduits, trunking, etc., from local boards to each item of
electrically driven appliance such as boilers, fans, fan heaters, motorised valves, etc., all
as later specified.
Electric motor starters, starter control panels and similar equipment will normally be
supplied under the Mechanical section of the contract but may be supply only, or supply
and erect (but not connect) or may be for supply and erect under this specification, all as
later specified.
Part 2 – Page 27 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
In any event accept any loose equipment so provided and install and connect this as
appropriate terminating with a final connection to each appliance, and supply and
incorporate any necessary additional equipment which will include an isolator adjacent to
the appliance when this is required.
Electric control wiring, conduits, trunking etc., from the point at which an electric power
connection is made is to be carried out under this Specification where later so specified.
The wiring for Mechanical Services is to be complete as specified with all cables, conduits,
trunking, switches, accessories, fixings, fuses, labels, circuits, lists, etc., except as later
specified.
2:1:43.0
Asbestos
No asbestos is to be used.
For work in existing buildings check within seven days of appointment if an existing
asbestos hazard may lead to refusal of staff to work and submit written notification of all
such hazards. If likely to be made part of the works submit also a quotation for replacing
the hazard with a suitable alternative.
If delays occur due to staff refusal in respect of a notified hazard, other than due to
failure to act in reasonable time upon instructions given to remove the hazard, then any
substantiated costs incurred due to the delay will be reimbursed, but no delay or delay
costs will be considered in respect of any non-notified hazard.
2:1:44.0
Poly
Chlorinated
Biphenyls
No substance containing any Polychlorinated Biphenyl may be used - it has been used as
cooling and/or insulating fluid in electrical equipment such as transformers, capacitors,
fluorescent lighting ballast, etc., and in hydraulic and heat transfer equipment. Common
"trade" names are Askarel, Aroclor, Clophen, Chlorextol, Dykanol, Fenclor, Inerteen,
Kanechlor, Moutar, Noflamol, Phenoclor, Pyralene, Pyrochlor, Pyranol, Sanothern FR,
Sovol, and Therminol.
2:1:45.0 CFC’s
No materials which contain CFC gases or use CFC gases in their manufacture are to be
used. CFC gases are as defined in the Montreal Protocol.
2:1:46.0
Treatment for
Shock Notices
"Treatment for Shock" notices, as produced by the Main Contractors Association or the
Electrical Times and complying with the requirements of the Factories Act (Electrical
Supply Regulations) shall be supplied and hung in each main switchroom, distribution
switchroom, plant room or adjacent to major distribution equipment locations.
2:1:47.0
Key
Box and Keys
Provide and install a wall mounted metal, painted, latched door, key box with fixed
internal key hooks for all electrical keys for switchgear, control panels, distribution boards
and the like. Each hook shall be numbered and bear a legend of the key reference i.e.
"Emergency Lighting Test Key". There shall be 6 spare hooks.
The references may be in the form of a typed sheet within a rigid clear plastic cover fixed
to the back of the door.
Each key hung on each hook shall bear a secured Formica disc with the key number
engraved in black. The Main Contractor shall hand over 2 No. of each key, minimum.
Part 2 – Page 28 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
The Main Contractor shall obtain instructions from the Main Contractor for the fixing
location of the key box prior to fixing the box.
2:1:48.0
Rubber Mats
All distribution centres and electrical plant shall be equipped with rubber mats laid on the
floor for the full length of all accessible sides and ends of the wall or floor mounted
assembly. Mats shall comply with BS and IEC requirements.
2:1:49.0
Inspection and
Testing
The Main Contractor shall be responsible for demonstrating the safety of the Electrical
Installations by carrying out tests in accordance with the IEE Regulations. The Main
Contractor shall carry out preliminary testing of the installation during installation,
submitting test results to the Contract Administrator for comment.
Final testing of the complete installation shall be carried out by the Main Contractor on
completion of works and results submitted to the Contract Administrator. The Main
Contractor shall give at least seven days notice prior to these tests taking place. All final
tests will be carried out during the same period of time, subject to sectional/early
completion of areas where the Contract Administrator may give approval for part testing
to be carried out.
The Contract Administrator reserves the right to be present and to witness all or part of
the testing.
He may also require, after completion of the Main Contractor's final testing, for selected
circuits (up to 10% of the installation) to be re-tested in his presence to prove the
accuracy of the results previously obtained. Failure to produce satisfactory results on the
accuracy will require the complete installation re-tested. This shall be at the Contractor's
expense.
An inspection of the installation as work proceeds, and upon completion will be carried out
by the Contract Administrator. It will be incumbent upon the Main Contractor to ensure
that his own supervision is carried out to ensure that all aspects of this Specification,
including the inspection schedule included in the IEE Regulations are complied with.
Tests shall be carried out in accordance with the IEE Regulations. For low voltage and
extra low voltage installations of the tests shall include:
·
·
·
·
·
·
·
·
·
·
Continuity of ring final sub circuits
Continuity of protective conductors including main and supplementary equipotential
bonding
Earth electrode resistance
Insulation resistance
Insulation of site-built assemblies
Operation of residual current devices
Polarity
Protection by separation and barriers
Earth fault loop impedance
Earth electrode resistance
For high voltage systems, voltage pressure tests shall be carried out to verify the integrity
of the insulation of equipment, cables and terminations. The test pressure shall be
appropriate to the RMS value of the system voltage, and the test carried out using
Part 2 – Page 29 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
approved equipment operated by a suitably qualified engineer.
Upon successful completion of the inspection and testing of all, or part, of the Electrical
Installation, the Main Contractor shall issue Inspection Certificates, and a Completion
Certificate generally as described in the IEE Regulations. In addition a test certificate
shall be completed for each distribution board installed, copies of which will be submitted
to the Contract Administrator.
In addition to the above, the Main Contractor shall, in the presence of the Contract
Administrator, test each and every sub-main cable and external underground cable
(regardless of use) and complete a "Power Cable Test Report Sheet".
All appropriate test equipment and instruments shall be provided by the Main Contractor;
all equipment shall be correctly calibrated and bear a current recognised
laboratory/makers calibration certificate.
Copies of all test, inspection and completion certificates shall be included in the Operation
and Maintenance Manuals, detailed elsewhere.
2:1:50.0
Commissioning
The commissioning of the Electrical Services Installations shall be the responsibility of the
Main Contractor. In order to carry out this work, the Main Contractor may employ
specialist commissioning engineers, and/or manufacturer's engineers, in addition to his
own staff should he so wish. ELV and communication systems such as fire alarms,
telecommunications, IT networks, security/access controls, CCTV, sound systems and the
like shall be commissioned by specialists.
Commissioning shall be defined as the advancement of the Electrical Installations from the
stage of static completion to full working order and the regulation of the installed systems.
Commissioning shall be commenced only after the necessary tests to prove the safety of
the systems have been completed and witnessed. Commissioning shall apply to all
electrical systems and equipment installed within this Contract. Fire alarms shall be
commissioned to BS 5839 Part 1 and emergency lighting shall be commissioned to BS
5266.
Commissioning shall be carried out in the presence of the Contract Administrator or their
appointed representatives, in order to ensure that the Operator is fully acquainted with
the function, operation and maintenance of all the electrical equipment and systems
installed. Should the Purchaser not be present during the commissioning the Main
Contractor shall demonstrate all functions, controls, equipment assemblies and installation
components to the Contract Administrator, to his complete satisfaction.
Commissioning shall be related to the Operating and Maintenance Manuals provided as
part of the "As Fitted" documentation, fully detailed elsewhere.
Where commissioning involves the full or part use of the Electrical Installations, i.e.,
energising distribution boards, lighting and power circuits etc., the Main Contractor shall
take account of the requirements of the Health and Safety at Work Act and the Factory
Acts. All necessary steps shall be taken prior to energising any equipment to ensure it is
safe to do so.
Written documentation, recording commissioning test results, certificates, etc., shall be
Part 2 – Page 30 of 31
RIDGE
Electrical Specification
Client Name :
Forestry Commission
Section 6
Project Title :
Sherwood Pines Visitors Centre – WC Block
Project Nr :
141200
Electrical Workmanship
provided, and included in the appropriate section of the Operation and Maintenance
Manuals.
Part 2 – Page 31 of 31
ofadb=
Pricing document
Client Name :
Forestry Commission
Project Title :
Sherwood Pines Visitors Centre – Proposed WC Block
Project Nr :
141200
Section 7
Building Tender Summary
Form of Tender
Client Name :
Forestry Commission
Project Title :
Proposed WC Block
Project Nr :
141200
RIDGE
SECTION 7
SECTION 7
BUILDING TENDER SUMMARY
£
2.1 DEMOLITIONS
2.2 EXCAVATIONS
2.3 NEW FOUNDATION
2.4 NEW CONCRETE SLAB
2.5 PAD FOUNDATIONS SUPPORT TO OAK COLUMNS
2.6 RAMP RETAINING WALL FOUNDATIONS & TIMBER
STAIR ACCESS
2.7 EXISTING AND BELOW GROUND SERVICES
2.8 NEW EXTERNAL WALLS
2.9 ROOFING
2.10 ROOF COVERING – MAIN AND PORCH CANOPY ROOFS
2.11 RAINWATER GOODS/DRAINAGE
2.12 EXTERNAL DOORS
2.13 WINDOWS
3.1 FIRST FLOOR CONSTRUCTION
3.2 GF INTERNAL WALLS
RIDGE
Form of Tender
Client Name :
Forestry Commission
Project Title :
Proposed WC Block
Project Nr :
141200
SECTION 7
3.3 WALL FINISHES
3.4 JOINERY
3.5 LINTEL TO DOOR/WINDOW OPENINGS
3.6 DECORATIONS
3.7 BUILDERS WORK AND M&E ATTENDANCE
3.8 SANITARY WARE
4.0 SITE AND LANDSCAPING WORKS
5.0 COMPLETION AND HANDOVER
_________________
TOTAL
To Main Summary
£
ofadb=
Pricing document
Client Name :
Forestry Commission
Project Title :
Sherwood Pines Visitors Centre – Proposed WC Block
Project Nr :
141200
Section 8
M&E Tender Summary
Pricing Document
RIDGE
Client Name :
Forestry Commission
Section 8
Project Title :
Sherwood Pines Visitors centre - WC Block Refurbishment
Project Number :
141200
£
a
Liaise with utility providers
b
Incoming Supplies & Connections
c
Sanitaryware & Fittings
d
Foul Drainage Above Ground
e
Cold Water Systems
f
Hot Water Systems
g
Rainwater Harvesting & Distribution System
h
LTHW Heating
i
Toilet Ventilation
j
Automatic Control Systems
k
LV Distribution System
l
General Lighting
m
LV Power
n
Emergency Lighting
o
Disabled Alarm
p
Telecommunications
q
Earthing & Bonding
r
Disabled Access Control
s
Fire Alarm System
t
Other Items Proposed by the Contractor
Total
ofadb=
Pricing document
Client Name :
Forestry Commission
Project Title :
Sherwood Pines Visitors Centre – Proposed WC Block
Project Nr :
141200
Section 9
Main Summary
ofadb=
Form of Tender
Client Name :
Forestry Commission
Project Title :
Proposed WC Block
Project Nr :
141200
SECTION 9
SECTION 9
MAIN SUMMARY
£
SECTION 1-
PRELIMINARIES
SECTION 2 -
MATERIALS & WORKMANSHIP
SECTION 3 -
SCHEDULE OF WORKS – BUILDING
SECTION 8 -
BUILDING SERVICES PERFORMANCE
SPECIFCIATION
_________________
To Form of Tender
£

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