Particular Specification For

Particular Specification - Part 35

PARTICULAR SPECIFICATION FOR ELECTRICAL INSTALLATION

1. Scope and Specification of Work

1.1 Installations/Systems

This Electrical Installation shall include the supply, installation, testing, commissioning and maintenance of the entire electrical installation as following systems and as listed in the Works Orders under this Contract and described in this Particular Specification unless otherwise specified:

1.1.1 Incoming Electricity Supply 1.1.2 Main and Sub-main Distribution 1.1.3 Lighting and Power Final Circuits 1.1.4 Luminaires 1.1.5 Cabling Facilities for Other Services 1.1.6 Lightning Protection System 1.1.7 Earthing & Bonding 1.1.8 Stage Lighting System 1.1.9 Nurse/Staff /Emergency Call System and Bedhead Trunking System 1.1.10 Low voltage cubicle switchboard system

The Contractor shall employ a specialist sub-contractor from “List of Approved Suppliers of Materials and Specialist Contractors for Public Works : Electrical Installation” – Group III.

1.2 Design Responsibilities

In addition to Clause 1.1, the Contractor shall be responsible for the design of the following systems and selection of equipment and components including the matching with other components to ensure that the systems conform to the specified performance requirements. The Contractor shall submit all design works including calculations and drawings to the Architect for approval.

1.2.1 Lighting and Power Final Circuits 1.2.2 Earthing and Bonding 1.2.3 Stage Lighting System 1.2.4 Nurse/Staff /Emergency Call System and Bedhead Trunking System 1.2.5 Low voltage cubicle switchboard system 1.2.6 Lightning Protection System

1.3 Compliance with General Specifications

All materials and workmanship shall comply with "General Specification for Electrical Installation in Government Buildings of the Hong Kong Special Administrative Region” issued by Building Services Branch, Architectural Services Department and any corrigendum issued thereafter (hereinafter referred to as the Electrical General Specification or G.S.) unless otherwise specified on the Drawings or in this Particular Specification.

1.4 The Contractor shall allow for liaison with the Supply Company in obtaining or upgrading the L.V. electricity supply including any necessary documentary submission.

The Contractor shall allow for liaison with other regulatory departments/authorities for approval of design and submission of necessary certificates such as WR1 and WR2 and any other necessary documents such as drawings.

- PS-35/1 - TC R318 Particular Specification - Part 35

1.5 Sample Board

Within 4 weeks after award of the Contract, the Contractor shall submit a common sample board containing samples of general items for the Architect’s approval.

The Contractor shall also submit sample board containing samples of specific items other than those in the common sample board for individual Works Order as required by the Architect for approval before the commencement of installation work.

1.6 Identification of Works Executed

The Contractor shall provide means such as labelling or marking for identification of equipment, material, fitting and component supplied and installed by him. The identification means shall be capable of differentiating newly installed works from the existing works systematically and cost- effectively.

When requested by the Architect, the Contractor shall submit records of the installation before and after the works have been carried out in the form of photos, drawings and the like as evidence that new equipment, material, fitting and component have been installed.

For replacement works, the Contractor shall be required to provide photo records of the items before dismantling, items being detached, and newly installed items.

1.7 Hidden Works

Hidden works refer to works that will be covered up, put out of view or ultimately removed so that they cannot be measured after completion. Examples are demolition works, temporary works and overtime.

At least one week before the planned execution of overtime work, the Contractor shall apply in writing for approval-in-principle from the Architect. The application shall indicate the estimated total labour time with date and time for the overtime work. Claims of overtime without approval- in-principle by the Architect will not be processed.

The Contractor shall submit Hidden Works Record with supporting information and certified by the Contract Manager or Project Manager to the Architect for endorsement:

(a) prior to hidden works being covered up or demolished, (b) within 1 week of completion of temporary works, or (c) within 3 working days on completion of the overtime work on daily basis, if overtime work is instructed by the Architect.

Hidden Works Record on overtime without the Architect prior approval will not endorsed.

Production of Hidden Works Record does not relieve the Contractor’s obligation under the Contract for examination of work by the Architect before covering up.

Claim for hidden works without endorsed Hidden Works Record will not be accepted unless justifiable reasons and supporting documents providing mechanism for measurement of hidden works can be given by the Contractor and approved by the Architect.

1.8 (Not used)

1.9 Testing Equipment

The Contractor shall provide the calibrated equipment and the associated calibration records etc. as the Particular Specification for Supply of Inspection, Measurement and Test Equipment in the

Contract

1.10 Specific Requirements

1.10.1 The Contractor shall be responsible for co-ordination and interface with the Low Voltage Cubicle Switchboard Installation Works (hereinafter referred to as Switchboard Works) for necessary connection and terminations of all main and sub-main distribution cables and other controls, earthing and bonding provisions with the Switchboard Works to the satisfaction of the Architect. The Electrical Specialist Sub-Contractor shall employ a specialist sub-contractor from “List of Approved Suppliers of Materials and Specialist Contractors for Public Works : Low Voltage Cubicle Switchboard Installation” approved by the Architect.

1.10.2 The Contractor shall provide in the Main Switch Room complete set of as-fitted schematic wiring diagrams of at size approved by the Architect drawn in permanent ink and each housed in a wooden frame with glazed front panel showing the complete electrical installation, to the approval of the Architect.

1.10.3 The Contractor shall be responsible for co-ordination with the Supply Company and the Switchboard Works to test and energise the electrical installation for proper operation matching with the building programme as well as the testing and commissioning schedules. The Contractor shall allow cost for such testing and commissioning to the satisfaction of the Supply Company and the Architect.

1.10.4 All main and sub-main distribution switchgears, control gears, MCB/MCCB boards, lighting and power final circuits connected to the switchboard, busbar chambers etc. shall be labelled in the way as specified in the EGS and to the approval of the Architect.

1.10.5 All control gears and switchgears, MCB boards, lighting and power final circuits connected to the essential supply system shall be labelled with engraved ‘Essential Supply’ in English and the equivalent Chinese characters. All labels shall be mechanically fixed and not by means of adhesives.

1.10.6 The Contractor shall also provide additional conduits, trunkings, wirings, copper tapes/bars etc. for the electrical bonding though such provisions may not be shown in the Works Order explicitly.

1.10.7 The positions and cable routes of all lighting and power points as shown in the Works Order are indicative only and subject to variation on site. The Contractor shall mark these positions on site after co-ordination with all other services installed in the same spatial zone, for the approval of the Architect prior to commencement of work. No claim due to such variation shall be entertained.

1.10.8 The Contractor shall note that for all flexible conduits used for the wiring works shall be complete with suitable adaptors at both ends of each conduit. Each adaptor shall comprise of two parts, an inner core which screws into the bore of the conduit together with a ferrule which caps off the end of the conduit, so that the adaptor can provide an extremely strong joint. The core shall lock against the outer ferrule and also isolate any sharp cut edges in the conduit which can damage cables on insertion or in use.

1.10.9 All lighting control switches for essential lighting circuits shall have front plates engraved ‘ESSENTIAL’, and the equivalent Chinese, in red.

1.10.10 All socket outlets, connectors, or similar power points connected to essential circuits shall be marked with engraved ‘ESSENTIAL’ in both English and the equivalent Chinese in red.

2. Additional Requirements

2.1 Nurse/ Staff/Emergency Call System and Bedhead Trunking System

2.1.1 General Requirements

The Nurse/Staff/Emergency Call Systems shall comprise of control panels, power supply units, call units, splash-proof type call buttons, emergency pull/push button, reassurance indicators, call buzzers, present/reset units, reset push buttons, communication facilities and all controls, wirings, etc. based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments.

All design, materials, and workmanship shall comply with Health Technical Memorandum HTM2014, HTM2015 and HTM2017.

The provision of bedhead trunkings together with facilities for power supplies (13A switched sockets), nurse call, bedhead light, medical gases and all other provisions shall be based on information and design criteria given by the Architect in the respective Works Orders and in accordance with this Particular Specification as well as relevant sections of the Electrical General Specification.

2.1.2 Specific Requirements

(A) Nurse/ Staff /Emergency Call Systems

1) The Call Systems shall be provided with visual and audible indication of call and alarm conditions. All these conditions shall be initiated by operating call push buttons and call switches.

2) There shall be different types of call systems with different provisions, based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments. They are categorized into the following two types:

(a) The call system shall be fully multiplexed and addressable. The sound distribution system and intercom shall also be integrated and multiplexed so that the distribution of signals for both call, sound and intercom shall be via a common data cable;

(b) The call system shall be a hard-wire system which shall use individual wires to communicate between communication points and the call panel.

3) To limit the effect of any local fault and to avoid affecting the entertainment signal elsewhere on the system, an isolating device shall be fitted between the entertainment distribution cable and the power supply/control units (P.S.U.). The unit to be supplied complete with a surface mounting enclosure, with stove enamel finish.

4) Generally the ancillary equipment such as call units, lamp units and reset units shall derive their power supply/signal from the nearest available bedhead unit.

5) All panel and unit layouts, full colour scheme, details of lettering, buttons and lamp arrangements in the system shall be submitted to the Architect / Maintenance Surveyor for acceptance before manufacture, whenever appropriate.

6) The description of call system equipment in this part of Specific Requirements shall be applicable for both nurse call, staff call and emergency call systems.

7) The complete call systems together with all the associated equipment, components, wirings, power supplies and installations etc. shall comply fully with this part of Specification, the Electrical General Specification, the General Requirements for Electronic Contracts, the relevant international standards, Health Technical Memoranda (HTM), with particular attention to HTM2014 and HTM2015, and HTM2017.

8) All the call systems shall be of the same make and supplied by a single proprietary manufacturer. All components and parts building up the system shall be compatible in every aspect in carrying out the required performance with optimum efficiency.

9) The call systems offered by the Contractor shall be designed, constructed and installed with due considerations on providing the best safety, serviceability, and ergonomic features, complying with all the requirements of this part of Specification and other obligations and recommendations as stated, and to the satisfaction of the Architect. Any access to live parts of the systems shall be possible only with the aid of a tool.

10) The control panels shall provide visual indications and audible alarm for each call system respectively and shall consist of call-ways and alarm-ways and installed at the locations based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments.

11) Each panel shall be made of sheet steel of robust construction of 1.6 mm minimum. The front plates of all panels shall be finished with 2.0 mm thick stainless steel irrespective of their mounting arrangement, having an indication light per call-way and a buzzer.

12) All components for the call systems shall be readily accessible and all wiring terminals shall be labelled and the wires to and from the terminals identified with numbered ferrules of insulating material. The wiring connections shall terminate at an approved type of terminal block, which shall also be suitably labelled. The labels and identification shall be consistent throughout the installation. To prevent interference from any high frequency source that is likely to be present, the wiring must be complete with appropriate shielding provisions.

13) The power supply units for the call systems shall each be connected to a 220V A.C. single phase supply via a 13A fused spur unit and give an output to power the whole system at 24V/28V D.C. safety extra low voltage level.

Each power supply unit shall comprise a class II transformer meeting with EN742 to provide the functional extra low voltage output (FELV), the primary winding of the transformer shall be connected to the 220V A.C. source.

Each power supply unit shall have sufficient rating for supplying rated output when at least 25% of the total number of calling points that connected to it, evenly distributed throughout the system, are operated simultaneously with corresponding indicating lights and buzzers activated, but in any circumstances shall not be less than 200 VA.

To ensure that acceptable volt drop levels are not exceeded when operating under the specified load conditions, account shall be taken to relate the manufacturer's published figures for the minimum operating voltages of their terminal equipment with the specified voltage output, at rated current, of the proposed power supply unit, to the satisfaction and acceptance of the Architect.

Appropriate and necessary rectifying, filtering and control circuits and accessories shall be incorporated in each power supply unit to provide a steady, regulated, and ripple free output voltage for the driving of the call systems connected. The supply units shall not be susceptible to any external interference that may be imposed on them, and they shall not cause any interference effects to other electrical or electronic equipment and circuits.

Circuit protection of the LV circuit shall be by fuse or circuit breaker. Circuit protection of the FELV circuits shall be by circuit breaker or automatic current limiting of the output. In all cases the protection device must be selected so as not to subject the wiring or components to permanent damage during the life of the installation through occasional overcurrent or short circuit conditions. If an automatic current limiting circuit is used then a visual indication of the state of the power supply must be incorporated and duplicated at all the corresponding call panels which are powered by the supply unit.

Each power supply unit shall be housed in a well-ventilated earthed metal enclosure with stove enamel finish, so that it is free from any external interference or cause any interference to other services nearby. The enclosure shall be protected to at least IP2X to IEC529, and shall have a clearly identified illuminated ON/OFF double pole switch mounted externally to provide isolation of all circuits fed from the source. The enclosure shall clearly display the rated input/output voltages and currents, the name, address and contact telephone of the contact personnel for maintenance.

Connections to each power supply unit shall be provided with a clearly identified terminal block with each terminal of sufficient size to accommodate at least three 1.5 mm² cables.

Separate power supply units shall be provided for individual nurse/staff/emergency call systems in each area/ward on each floor. Each power supply unit shall serve the same cable systems on each of the same floor/level which have been interconnected to facilitate alarm transfer. The call systems shall be complete with an uninterrupted power supply system such that no call or message shall be lost during power interruption. The power supply system shall be capable of maintaining the call systems in operation for a period of at least 30 minutes.

For each ward or area or each floor, at least one combined power and control unit shall be provided. The unit shall have the capability to control up to 60 beds or points.

Each unit shall be placed in a location which shall be easily accessible but shall be concealed from view as accepted by the Architect.

14) A fault monitoring and recording system shall be provided for each nurse call system so that if a patient's plug-in pendant or pull cord switch is removed from the socket, a call shall be initiated on the associated nurse call panel, and the event be recorded by the system for reporting when called for. all faults shall also be recorded for reporting when called for, and a fault indication to indicate the instant when it occurs shall be provided.

15) Calls occurring simultaneously or consecutively shall be registered by the appropriate zone indicators and no call shall be lost.

(B) Multiplexed Call Systems

1) The call indicator panel shall be connected to the P.S.U. with a 2 pair data cable and an 1 pair 24/28V D.C. power cable. The panel shall be flush mounted with overlapping stainless steel plate. An 1 pair cable shall also be required to supply tone output. Indication shall be by high brightness LED, with additional indication of : Power on, and Fault.

2) Each ward or area shall have a 24/28 volt D.C. 2 core power cable together with a 2 pair data cable emanating from the P.S.U. both connected into the bedhead units and returning to the P.S.U. to form ring circuits.

3) The P.S.U. shall accept the entertainment signal which is transmitted from the central sound distribution multiplexer unit. From the P.S.U. the signal will be transmitted round the data loop to each of the bedhead positions where the digital signal is decoded as conventional sound.

4) The system shall be capable of providing up to 14 channels of radio and television sound with 5 spare channels for future expansion. To boost the signal, a repeater shall be installed if any continuous run of data cable exceeds 300m or any appropriate shorter length as recommended by the manufacturer on the main distribution wiring to the satisfaction of the Architect.

5) All system wirings between call points and control panels shall be of multiplexing cables. All electronic components for the systems shall be modular in construction, and contained on detached and replaceable printed circuit boards.

6) All interconnecting cables between system equipment shall be twisted wire pairs suitable for multiplexing signals communication. They shall, whenever possible, be grouped and laced together in a neat manner. Different colours shall be provided to distinguish the various circuits. Wiring from the fixed part of the panel to the movable part, such as hinged front plate, shall be enclosed by a flexible PVC tubing. Connectors or soldered joints are not permitted in the wiring. All exposed live terminals shall be suitably shrouded or covered.

(C) Call Panel

1) The call panel shall provide visual indications and audible alarm for the nurse call system and shall include call points for staff call system. It shall include call-ways and alarm ways.

2) The call panel shall include a 24V D.C. power supply unit which shall be fed by a 13A fused spur unit.

3) Call delay transfer function shall be provided between the nurse call panels in adjacent wards and between the nurse call panel and call panel in specified Nurse Officers’ Rooms or other locations specified by Client.

4) A push-to-call, push-to-reset "STAFF CALL" button shall be provided on the nurse call panel to call for staff.

5) "MUTE" and "TEST" buttons shall be provided at the nurse call panel to mute the audible alarm and test the panel.

6) The call indicator on the nurse call panel and emergency call panel will also be referred to as the 'Zone indicator'.

7) A buzzer muting keyswitch and an ON/OFF keyswitch for the power supply shall be provided on each control/alarm panel. Means shall also be provided inside the control panels for adjusting the sound levels of the buzzers, which can only be accessible however with the front plate of the panel be opened up.

8) The tones of sound for buzzers of all the same type of call control/alarm panels shall be the same, but shall be distinguishable from those of other types.

9) There shall be different types of call panels with different constructions and provisions, based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments.

10) Call panel with LCD display/integrated computer graphic display, with or without intercom station:-

The panel shall be proprietary unit constructed with thermo plastic structural foam and shall be suitable for desk/wall mounting. Each panel shall provide both LED indications of call locations and a 2 lines x 40 character display, (or integrated computer graphic display) as a minimum. The panel shall be capable of indicating incoming nurse, staff or emergency calls; incoming transferred calls; nurse presence and system faults etc. When in quiescent condition the display shall give the date and time. The operator shall be able to acknowledge incoming calls. Intercom station shall be provided as required.

11) Call panel without LCD display, with or without intercom station:-

Such panel shall have similar provisions as the type (a) panel as mentioned above, but without the LCD display. Each panel shall be proprietary unit constructed with thermal plastic structural foam or stainless steel, and shall be suitable for wall mounting. Each panel shall have nurse, staff and/or emergency call indicators, call “ACCEPT” button, “TALK” button and the associated speaker and microphone for speech communication. Lamp test and buzzer muting switches shall also be provided. Intercom station shall be provided as required.

12) Call panel with touch screen control, with or without intercom station:

In addition to similar provisions as the type (a) as mentioned above, the panel shall be typical “PC” arrangement with a self-contained touch screen console and operated within “Windows” environment. It shall provide graphical display facility (e.g. with mimic ward layout diagram identifying exact location of the call/ event) to display the patient records on demand or automatically in the event of a call and 2-way speech communications to all call points equipped with communications modules. Logging of all calls within the ward area with the time and date of each call shall be provided and the logged calls should be able to store in disk allowing retrieval and analysis at a later date. The operation configuration shall be able to configure to meet the specific site requirements. The panel shall have the features including call logging and generation of reports, logging of engineering events, turning on/off individual outputs, simulating individual input active and inactive states, isolating a bed, tone masking, ward loop trace facilities, flexible transfer, transferring beds, and printer output. Intercom station shall be provided as required.

(D) Call Unit

1) Call unit shall be either flush mounted on wall or flush mounted on bedhead trunking by fixing to a back box inside the bedhead trunking. The call unit shall comprise of the combination of call button, present button, reset button,

reassurance indicator, emergency call button, handset jack socket and 2-way intercom station based on information and design criteria given by the Architect.

2) The Contractor shall coordinate the openings on the faceplate and compartmentation of the bedhead trunking for installation of the nurse call equipment.

3) The call push button shall be amber in colour. The reassurance indicator shall be lit individually on operation of the call push button. Illumination of the reassurance indicator shall only occur when the associated call point is operated. The labeling of the nurse call push shall be the same as those on the handset as described in this Particular Specification.

4) The push button shall have a current rating of not less than 5A at 24V D.C.

5) Wall mounted push buttons shall be fixed to a wall cast-in BS 4662 steel box.

6) All push buttons shall be suitably labeled in both Chinese and English characters and letters engraved on the button front plate or on the bedhead trunking front plate, to the approval of the Architect.

(E) Splash-proof Type Call Switch

1) Splash-proof call switches of push cord type or push button type shall be provided in toilets, showers, bathrooms, assisted baths and other locations as specified.

2) Each splash-proof call switch shall have a moulded white flush plate.

3) A reassurance light of amber colour shall be provided on the switch plate which shall be lit individually on operation of the switch. Illumination of the reassurance light shall only occur when the associated call point is operated.

4) Each call switch shall be fixed to a BS 4662 steel box recessed mounted on the wall and shall be suitably labeled in both Chinese and English characters and letter engraved in amber colour on the flush plate.

(F) Multiplexed Nurse Call Handset

Plug-in type multiplexed nurse call handsets /patient remote call units for all the bedhead units and other designated locations based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments shall be provided. The nurse call handsets shall comply with the following requirements:-

1) Each handset shall be provided with a 2 m long flexible cord and a jack plug for use and compatible with the nurse call jack socket in each behead unit and other locations as shown on the drawings.

2) The nurse call handset shall be of moulded case, waterproof, wipe-clean and capable to withstand up to 90kV electro-static discharge.

3) The jack plugs and the associated jack sockets shall be installed such that the plug can be inserted or withdrawn satisfactorily when subjected to excessive forces applied at any angle to their axes without damage.

4) The patient/nurse call function of the handsets shall be continuously monitored and a call condition shall be set up on the associated nurse call panels in the even of the jack plug to the bedhead or wall mounted panel being withdrawn or an open

circuit cable fault developing. The call so initiated shall not be resettable until the handset has been re-coupled or the fault rectified.

5) The Contractor shall allow or the supply for each bedhead unit an additional spare dummy jack plug which has no connecting handset. The plug shall be internally wired in such a way that when the plug is inserted into the jack socket on the bedhead unit, it will simulate a properly handset correcting condition so that no call/fault condition will be initiated. Any nurse call will have to be initiated from the similar call provision on the bedhead unit itself as described elsewhere in this part of Specification.

6) In order to avoid false calls due to switch bounce when the handset is dropped or knocked, the nurse call function shall not be sensitive to a switch operation of less than 5 milliseconds.

7) Handset assemblies shall be lightweight. An anti-slip device shall be incorporated, so that the handset is not dragged onto the floor by the weight of the cable when placed on a standard over-bed table.

8) The multiplexed handset shall comprise of the combination of the followings based on information and design criteria given by the Architect :-

(a) A back illuminated circular orange nurse call push button. (b) A reassurance indicator. (c) A push-switch for on/off control of the bedlight. (d) A push-switch for selection of up to 14 sound channels. (e) A channel indicator. (f) Control for the volume of sound output.

The handset shall operate on a 4-core system with two cores being exclusively used for the nurse call signal.

The handset shall be fully compatible with the bedhead unit and integrated entertainment sound distribution system.

9) The nurse call button shall be coloured and bear an engraved 'nurse' symbol to the approval of the Architect. It shall be the largest button on the unit and shall be permanently illuminated. The level of luminance shall be such that the button can be easily located in the dark, but it shall not be so bright that it is confused with the reassurance lamp. The shape of the button shall readily distinguish it from the other push buttons.

10) A high-brightness reassurance indicator which illuminates when the nurse call button has been pressed shall be incorporated. It shall remain lit until the call is cancelled at the bedhead panel. The lamp may either provide backlighting for the nurse call button, or may be provided as a separate indicator lamp. In the latter case, it shall be close enough to the nurse call button that its function cannot be confused. An audible and tactile 'click' sound shall be incorporated as well, as a reassurance that the call has been registered.

11) Linen clip shall be provided that allows the unit to be attached securely to sheets or patient's clothing, whilst allowing the unit to pull away without tearing the material if violent force is applied. Suitable types of clip shall be submitted to the Architect for approval.

12) Each call handset shall be complete with a parking device.

13) The connecting cord shall be positively retained within the handset, and a strain relief grommet shall be fitted.

14) No electrical conductor or component within the unit or the connecting cord shall be at a peak potential of greater than 30V either between conductors or between conductor and earth.

15) Due consideration shall be made to minimize the effects of electrical and electrostatic interference.

16) It shall comprise one internally mounted impulse type relay for bedlight operation via the multiplexed patients handset.

17) The handset shall be complete with microphone and speaker for communication with the nurse call panel as required.

(G) Call Indicators

The nurse call indicator light for both nurse call and staff call shall either be wall mounted above the door or ceiling mounted on the false ceiling. Individual bracket and BS 4662 box shall be provided for firm and proper fixing the call indicator light to the ceiling/wall slab.

Generally, the indicator light shall be lit in AMBER when any call button in the room is actuated. The indicator light shall change from AMBER to CLEAR when the ‘Present’ button at the bedhead trunking or in the case of bathrooms toilets at the entrance to the room, is pressed. The indicator light shall be extinguished by pressing the ‘Reset’ button at the bedhead trunking or other specified locations.

(H) Call Buzzer

Call buzzer shall be provided in the call panels and buzzer/indicator units at specified locations.

Unless specified to silence when the call button is released, the call buzzer shall give a continuous (but variable interval) audible alarm under a call condition and shall be silenced by pressing the ‘MUTE’ button on the panel or the remote ‘present/reset’ unit.

(I) Present/Reset Unit

The ‘Present/Reset’ unit shall be provided at the bedhead trunking or, in the case of bathrooms or toilets, at the entrance of the rooms as appropriate or specified.

On attending a call, the nurse will press the ‘Present’ button which shall turn the call indicator light from AMBER to CLEAR. Meanwhile, the zone or location indicator light on the nurse call panel shall automatically extinguish.

The ‘Present’ button shall be in white colour while the ‘Reset’ button shall be in amber colour.

The ‘Present/Reset’ unit shall be suitably labeled in both Chinese and English characters and letters engraved on the flush plate, to the approval of the Architect.

(J) Nurse Call System

When a call is initiated either by pressing the call button on the bedhead trunking, hand pendant, bathroom or toilet call switch or removal of a hand pendant unit or a jack plug,

the reassurance light on that particular call unit shall illuminate.

The nurse call indicator light mounted above door or at ceiling shall illuminate in AMBER colour.

The corresponding zone or location indicator on the nurse call panel at nurse station or other locations as shown on the drawings shall also illuminate and the buzzer on the nurse call panel shall sound.

The duty nurse will press the ‘ACCEPT’ or ‘MUTE’ button on the nurse call panel to mute the buzzer but the zone indicator shall remain illuminated.

After identifying the zone from the indicator on the nurse call panel and the overdoor indicator, the nurse enters the room where the call originates, identifies the source of the call by the illuminated reassurance lamp and presses the nurse present button. This shall change the overdoor indicator colour from ‘AMBER’ to ‘CLEAR’, and shall automatically extinguish the zone indicator on the nurse call panel.

If another call is initiated at the same bedroom, the overdoor indicating lamp shall automatically change to "AMBER", the zone or location indicator shall illuminate and the buzzer shall operate on the nurse call panel with another cycle being repeated.

After the completion of the call attendance, the nurse will press the reset button at the present/reset unit to extinguish the overdoor indicator and reset the call.

(K) Staff Call System

The Contractor shall provide the staff call system for calling from nurse stations or other specified locations based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments.

The staff call panel shall provide visual indications and audible alarm for the staff call system. The staff call panel shall include location indicators for indicating the respective locations where the calls are initiated, call buzzer and ‘LAMP TEST’ button. ‘MUTE’ button shall be provided where the buffer is initiated into continuous operation.

When a call is initiated by pressing the ‘STAFF CALL’ button of the corresponding panel, the buzzer and the corresponding ‘location’ indicator shall be energized on the staff call panel at the associated area.

The duty staff will go to the corresponding nurse station to assist the nurse.

The duty nurse will press the illuminated ‘STAFF CALL’ button again to reset the call system and extinguish the indicator lamp at the staff call panel.

(L) Emergency Call System

The Contractor shall provide the emergency call system with pull/push type call button at the bedhead unit or other areas based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments.

The performance of the emergency call system shall be identical to the nurse call system except whenever the emergency call button is pressed, all indication points including at the nurse station and in the nursing officer and in the pantry and other specified areas of the entire zone will be responded to this call.

This emergency call shall only be reset by pressing the reset button next to the

emergency call point which initiates the call.

(M) Central Multiplexed Sound Distribution System

1) General

The Contractor shall design, supply, install, supervise, test and commission central multiplexed sound distribution system for the Hospital based on information and design criteria given by the Architect in the respective Works Order.

An integrated sound distribution system shall be supplied, which utilizes the same data cable as the main nurse call system wiring.

Multiplexed techniques shall be used to provide a maximum of 15 channels plus of high quality sound to the patient’s bedhead and other output devices. Television sound shall be transmitted as 4 of the 15 available channels. No connection will be required between local (ward) television sets and the integrated sound distribution system. Additional 5 channels shall be provided for future use.

2) Central Unit

A central desk/shelf mounted unit shall be provided to receive signals off air, and encode them for onward transmission around the site.

The central unit shall be modular in construction, and totally self contained and fitted with the following plug-in modules.

(a) Power Supply (b) Control/Monitor Module (c) TV 1 Tuner 1 ...... Channel 1 (d) TV 2 Tuner 2 ...... Channel 2 (e) TV 3 Tuner 3 ...... Channel 3 (f) TV 4 Tuner 4 ...... Channel 4 (g) FM Tuner Stations 1-2 .. Channels 5-6 (h) FM Tuner Stations 3-4 .. Channels 7-8 (i) FM Tuner Stations 5-6 .. Channels 9-10 (j) AM Tuner Stations 1-2 .. Channels 11-12 (k) Aux Audio Input ...... Channels 13-15

The choice of which tuner is output to which Channel should be selectable from the Control Unit

All tuners should be ALL synthesized tuners for zero drift and on station stability.

3) Distribution

The multiplexed signal shall be distributed via a 4 core screened data cable. 4 outputs shall be provided from the central unit. If any cable length exceeds 300m or other shorter length as recommended by the manufacturer to the acceptance of the Architect, on the main distribution run a repeater/signal booster shall be installed. The data cable shall enter ward areas via the nurse call power supply unit or via a ward isolator, as appropriate, depending on the system design.

The wiring shall be installed as a ring circuit throughout the ward, connecting every bed or point to the common data cable. Multiplexed decoder units (plug in modules) shall be fitted in each bedhead unit to convert the digital signal to a conventional sound output.

Data cable or decoder module faults occurring within the ward/area shall be indicated by local LED and should not affect the system within other areas.

(N) Other Requirements

An uninterrupted power supply system for the call systems such that no call or message shall be lost during the power interruption and the power supply system shall be capable of maintaining the call systems in normal operation for a period at least 30 minutes.

(O) Bedhead Trunkings and Facilities

1) The Contractor shall supply, assemble, install, supervise, test and commission bedhead trunkings together with facilities for power supplies (13A switched sockets), nurse call, bedhead light, medical gases and all other provisions based on information and design criteria given by the Architect in the respective Works Orders and requirements from the client departments and in accordance with this Particular Specification as well as Section 5 of the Electrical General Specification.

2) The aluminium bedhead trunking shall be of proprietary product and be assembled as a continuous horizontal surface wall mounted trunking with compartments for low voltage (LV) essential and non-essential services, functional extra low voltage (FELV or ELV) and medical gases installation. The compartments shall be mutually segregated by earth metal separation barriers. The section for medical gases shall be capable of accepting a minimum of 4 numbers 15mm outer diameter pipes and shall allow sufficient space for connection and installation of medical gas terminal units.

3) The compartmented bedhead trunking shall house the services as follows and/or as shown on the drawings:-

LV- 13A socket outlets (single or twin), bedhead luminaires & switches and the L.V. wiring. The minimum height of the compartment shall not be less than 30mm.

ELV. - Nurse call buttons with pear push socket, ELV outlets, and all the associated wirings. The minimum height of the compartment shall not be less than 30mm.

Medical Gas - Medical gas terminal units and pipework. The minimum height of the compartment shall not be less than 120mm.

4) The Contractor shall be responsible to ensure that sufficient space is allowed in each compartment for installation of the required wiring, pipework and outlets, etc.

5) A vertical compartmented trunking for LV, ELV and medical gas installation shall be provided for connecting the bedhead trunking to the horizontal trunking inside the false ceiling. The LV compartment shall be connected to both the essential and non-essential lighting and power trunkings each with 25mm dia. conduit for wiring to the bedhead lights and sockets. The ELV compartment shall be connected to the horizontal major compartment of ELV trunking inside the false ceiling each with 32mm dia. conduits. All conduit shall be complete with draw wires.

6) The Contractor shall liaise with all other parties to obtain the precise dimensions

of all the necessary services on the front faceplates for the bedhead trunking. The supply and installation of all trunking front faceplates and the openings for all the outlets shall be included in this part of the Contract work.

7) Mock-ups of the sample proprietary made bedhead trunking with length approved by the Architect / Maintenance Surveyor shall be provided by the Contractor prior to ordering. This sample bedhead trunking shall include all typical outlets on the faceplate. The exact timing and location of the mock-up will be determined by the Architect. The Contractor shall include in the Contract a price for such work of installation and dismantling of the sample bedhead trunking, matching with the working programme as directed by the Architect.

8) The bedhead trunking design shall have access to live parts in the trunking only be possible with the aid of a tool. Bedhead panels when fully assembled mush provide a degree of internal protection (IP) of at least IP2X over all exposed surfaces other than horizontal top surfaces, which mush be IP4X to IEC529. All edges or gaps shall also be sealed to prevent dust or insect ingress.

9) To allow bedhead panels to be partly dismantled for servicing or inspection, LV, ELV and medical gas compartments shall remain to be operational and shall be capable of maintaining the degree of protection outlined above, or as stipulated in the relevant Specifications

10) The overall construction of bedhead panels shall be stable and sufficiently durable to maintain reliably the relevant degree of IP protection throughout the expected life of the installation. Appropriate allowances mush be included in the design of bedhead panels to take into account normal building tolerances, wall surface finishes, positional misalignments etc. likely to be experienced in practice during installation by the Contractor.

11) The bedhead trunking shall be completed with earth terminals for all sections as durable brass earthing studs having efficient and reliable electrical connections, and the Contractor shall be responsible for the bonding of the trunking system, including the conduits and connection boxes, to the main earthing system and ensure that a sufficient earthing conductivity and continuity of the trunking system can be achieved.

12) The details of the bedhead trunking including dimensions in section and method of construction shall be checked in situ. The Contractor shall ensure that the dimensions and new trunkings are matching and compatible with the existing trunkings.

13) The trunking shall be factory fabricated and constructed from anodized aluminium extrusions and 1.6mm zinc electro-plated sheet steel assembled as indicated. The components shall be finished to remove all sharp edges and pop riveted together using stainless steel rivets. The completed sections shall be carefully aligned and surface fixed to the walls. The extruded sections shall be cut to form continuous joint free lengths for each wall-to-wall section and the sheet steel assembled in cut pieces.

14) All services outlets shall be flush mounted on the anodized aluminium faceplates arranged as proposed on the drawings, forming the bedhead units. The functions of the service outlets shall be marked with engraved English and Chinese characters as relevant, and to the approval of the Architect.

The service outlet faceplates shall be mounted to form part of the front cover plate

of the bedhead trunking.

15) The faceplates shall be accurately machined to provided close fitting openings for outlets, suitably finished to provide corrosion protection, and with non-reflective surfaces.

The faceplates shall be 2mm thick anodized aluminium sheets with smooth edges. They shall overlap each edge of the bedhead trunking by not less than 12mm. Separate faceplates shall be provided for all services such as the LV, ELV, bedhead luminaires and medical gas compartments. All essential and non-essential electrical services shall be segregated.

The faceplates shall be securely fixed with countersunk screws or other means as approved by the Architect and can only be removed with the aid of a tool. A means of ensuring alignment of the adjacent edges of the two plates shall be incorporated, and a covering strip to cover up the edges shall be fitted to provide a sightly arrangement.

All internal components attached to the faceplates shall be fixed in such a manner that no screws or other means of fixing are visible from the front of the panel. The front surface of the cover plates shall not become visibly deformed by stresses set up by the various fixing arrangements.

A metallic barrier shall fully segregate the trunking into different enclosures, LV essential and non-essential, ELV and medical gases. The barriers shall be securely attached and electrically bonded to the LV cover plate. The arrangement shall enable the LV, ELV or medical gas compartments to be individually accessible without the other two supplies to be isolated and vice versa.

16) All electrical and medical gas components shall be fixed to the back of the faceplate by welded studs accurately located with stainless steel nuts and lock washers.

17) The medical gas terminal unit shall be fixed to the back of the trunking by the Contractor included in other parts of this Contract and the faceplates shall require machined openings for the gas outlets made by the Contractor. The Contractor shall coordinate the work with all other relevant parties.

18) The bedhead trunking shall be equipped with all anodized aluminium dummy front plates of the same construction, material and thickness as the faceplates, and other necessary accessories to ensure a neat and uniform appearance.

19) All controls and components, unless stated elsewhere, shall be mounted on the appropriate boards as modules to facilitate maintenance by exchange and the use of 'dummy' plugs and boards assemblies in the event of faults developing in the unit.

20) The faceplates layout, full colour scheme and detail of lettering shall be submitted to Architect for acceptance prior to manufacturing.

21) Controls and components for the bedhead system shall be designed to ergonomic principles. Symbols for the various controls shall be permanently marked by engraving on the corresponding faceplates.

22) The services, controls and components shall comply with the followings:-

Power socket outlets shall be single or twin 13 A, shuttered type, with

(a) Power socket outlets: RCD to IEC755.

(b) Bedhead luminaires control switch

The switch shall be 5A on/off switch for bedlight operation and of white PVC rocker and bezel type suitable for flush panel mounting, manufactured by the same manufacturer as the socket outlet as mentioned above. It shall be quiet in operation, and comply with BS 3676. The switch shall be complete with a capacitor with integral discharge resistor for the dimming of the tungsten lamp bedlight. The panel adjacent to the switch shall carry the engraved wordings "BEDHEAD LIGHT" and “Down Light” and the equivalent Chinese and corresponding symbols. The switches shall control the respective bedhead lights and down lights respectively.

(c) Fused spur unit for bedhead luminaires supply

The fused spur unit shall be of the flush mounted carrier pattern type suitable for use on a ring circuit and incorporating a fuse to IEC269. The fuse shall be readily replaceable without the need to remove the faceplates. The panel under the fuse carrier shall be engraved labeled "Bed Light" and the equivalent Chinese characters.

(d) Nurse call handset jack socket

Nurse call outlets shall comprise 4-pole jack socket for multiplexed patient pear push handset and shall be from the same manufacturer as the nurse call system equipment. They shall be compatible in functions and installation. A nurse call push point complete with reassurance light shall be provided on the bedhead trunking.

(e) Nurse call handset and its storage parking bracket

A parking bracket shall be supplied and installed by the Contractor for each nurse call handset at a suitable location satisfying the followings and to the approval of the Architect, for the storage of the patient nurse call hand set.

The brackets shall be fixed to the bedhead trunkings and the lockers by a positive means other than by adhesive, to the approval of the Architect. When the handset is parked on the locker, it shall be possible to operate all the controls in situ, using one hand only. The handset shall be in its normal ready operating position with symbols correctly orientated.

The handset shall be easily placed into or removed from the parking bracket, even by a frail patient lying supine or prone, whose arm is at full stretch. It shall not require a force greater than the weight of the unit, nor any difficult manipulation to achieve parking or separation of the handset.

The parking system or a separate clip shall enable the hand set to be attached to bedding or patient's clothing, but if the hand set is pulled away forcefully, it shall separate without tearing the material.

The handset shall locate positively in the parking bracket and not be accidentally dislodged by such knocks or pulls that are to be expected in normal service. However the installation of the bracket shall preferably enable the hand set and the bracket to separate under abnormal forces, such

as when the cord is caught on the bed and the bed is then pulled away from the wall. This separate shall not cause any damage to the bracket, handset or the connecting cord.

The maximum projection of the parking bracket shall not exceed 20mm and all edges and corners shall be rounded to avoid injury. The bracket shall be made of a deformable material to reduce the risk of injury and breakage.

(f) Bedhead and down light luminaires

The bedhead light and down light fitting shall be supplied and installed by the Contractor as required by Works Orders. The luminaire shall be suitable for either fluorescent or compact fluorescent lamp as required. The bedhead luminaire and illuminance shall also comply with the requirements of Institution of Building Services Engineers (CIBSE) Guide – Hospitals and Health Care Buildings, and IEC598 as relevant, with double electrical insulation, the Contractor shall supply and install the light fittings on the trunkings with proprietary purpose-made brackets of adequate strength and rigidly fixed on a faceplate and well fitted on the bedhead trunking. The installation of the fitting shall be such that it shall not strike on the wall or glazed partition when stretched, retracted, or moved.

(g) Medical gas terminal units

Medical gas terminal units complete with all baseplate, pipework and fixings shall be supplied and installed as included in other part of this Contract but the Contractor shall allow for the coordination with others for the exact opening on the faceplate complete with baseplate to accommodate the necessary medical gas outlets.

(h) Audio Outlets

Audio outlet for radio and TV sound systems shall comprise channel selector buttons volume control audio driven unit complete with jack plug for stereophone headset, etc. The Contractor shall also supply 1 no. stereophone headset with foam ear tips, complete with 2 m tubing for each radio and TV sound outlet. Details of the provisions are as mentioned in other sections of this part of Specification. The Contractor shall supply and install the whole radio and TV distribution system as specified in the Contract.

(i) Faceplate for other services

The Contractor shall provide anodized aluminium faceplates for the panels of patient monitoring system and speaker for intercom system as required.

23) The Contractor shall measure the exact dimensions of bedhead trunking for each room prior to ordering. The Contractor shall also render the best co-ordination and cooperation with all involved parties for the installation of all services for the trunking system, to the satisfaction of the Architect.

24) Notwithstanding the layout of the provisions mentioned in the above clauses, the Contractor shall arrange the provisions in according to the ergonomic principles. All control switches, light switches and socket outlets on the bedhead units for use by the patients shall be easily and conveniently accessible to them when they are on beds. Such controls are preferably located on the left hand side of the respective beds. The Contractor shall submit detail layout to the Architect for approval prior to work.

25) Internal wirings of all equipment shall be carried out by the Contractor in a neat and competent manner. Both colour coding and identification sleeves at terminations shall be used, and the identification shall be consistent throughout the installation. Connection wiring diagrams shall be provided which shall bear either the colour code or sleeve identification to enable ease of connection and identification.

Internal wiring shall be PVC insulated multistrand cables with the appropriate current and voltage rating. Cables between the faceplate assemblies and back box mounting connectors shall be formed into harnesses appropriate. All wirings passing from one side of the segregation barrier to the other shall pass through the barrier by means of a grommet hole. The wiring shall be fully shrouded at its connections. Wirings for essential and non-essential services shall be segregated as accordingly to any relevant Specifications.

26) A suitable cable harness with a polarized multipin connector shall be provided for the connection for all external system circuit wiring from the back box terminal block to the faceplate assembly for ELV enclosure.

27) The connector shall be of durable construction having good positive alignment.

28) A layer of insulating material shall be fitted between the base of the terminal block and back box overlapping the edges of the terminal block by not less than 10mm and marked clearly and indelibly with each terminal way number and/or circuit reference. The terminal block shall be manufactured from a high quality material having shrouded connector, a minimum cable entry of 4mm² and minimum rating of 10 Amps.

29) The LV power circuit wiring shall be connected directly to the terminals of 13A socket outlet.

Wiring from the bedhead luminaires and associated control to the relevant circuit connections on the LV cover plate assembly shall be by means of a terminal block, generally as described for the ELV enclosure above, mounted to the inside of the L.V. cover plate.

2.2 Busbar Trunking system

2.2.1 All busbar trunkings, or busducts shall comply with the Electrical General Specification and shall be of low impedance all insulated type with copper conductors housed in a totally enclosed non-ventilated galvanised steel housing, protected against mechanical damages and dust accumulation.

2.2.2 All fittings such as plug-in units, elbows, flanges and connection accessories shall be from the same proprietary manufacturer compatible with each other and having the required current ratings. Plug-in MCCB or fused units and flange end units shall be provided as required.

2.2.3 All of busducts shall be used purely for electrical ducts only, with a degree of protection of not less than IP65 to BS EN60529 as specified in the Electrical General Specification.

2.2.4 All tap-off openings along the busbar riser shall be provided with hinged water tight covers completed with locks and keys. Each phase bar at a plug-in opening shall be

individually insulated and segregated.

2.2.5 At every location where the busduct passes through floor or wall, a tailor made feeder section in such a way shall be provided such that the busduct can be removed from either side of the floor/wall opening without affecting the remaining installation.

2.2.6 Busbar risers/trunkings shall be protected against water ingress. All wetted and/or damaged busbars must be replaced.

2.2.7 Where busducts pass through floor slabs, a minimum waterproof concrete curb of not less than 200mm high or at least 100 mm higher than that of any other curbs in the same room, whichever is the higher, shall be installed.

2.2.8 Where busducts pass through fire rated partitions, the opening shall be filled up with appropriate fire rated materials.

2.3 X-ray Viewer

2.3.1 The viewers are capable of being bolting together to form continuous rows of viewers. The X-ray viewers shall comply with DIN 6865 and IEC 601 or equal and shall be CE marked.

2.3.2 The housing and the viewing panel of all X-ray viewers shall be made of aluminum and unbreakable acrylic glass respectively. The film holding device shall be made of stainless steel and shall hold the film in place simply by pushing the film under it. All film viewing panel shall be made of unbreakable acrylic glass with its viewing surface not less than 800 x 450mm. Each X-ray viewers shall equip with 4 nos. of 15W daylight tubes or as specified and special ballast resistors that guarantee low heat dissipation of the X-ray viewers. The color temperature of tubes shall be around 6500 kelvin. Furthermore, the lightness per lux and the luminance per cd per m2 shall be around 5800 and 1700 respectively. The X-ray viewer shall perform a unique brightness on viewing surface, appearance of shading would not be allowed.

2.4 Ultra-violet Sterilizing Light (UV)

2.4.1 The UV sterilizing light shall be factory assembled and tested to be capable of killing mold and other airborne microbial contaminants such as cold, flu and measles viruses, Legionella, tuberculosis and other bacteria, viruses and mold spores. The testing certificate shall be submitted for approval.

2.4.2 UV sterilizing light shall be suitable to be installed inside air-conditioning ductwork and maintain high effectiveness under such conditions.

2.4.3 All electrical wiring shall be in accordance with the current IEE Wiring Regulations and the recommendation of the manufacturer and comply with the relevant standards. All necessary electrical cables/accessories for proper operation of the complete installation shall be provided.

2.4.4 UV shall not generate substances in excess of the safety standards specified by the Occupational, Safety & Hygienic Association (OSHA), USA and Food & Drug Association (FDA), USA.

2.4.5 UV shall consist of emitter tube /sockets, stainless steel housing, power source, power cover, reflector, socket holders.

2.4.6 Emitter tube shall consist of electrodes, glass tube and a thread connector at the base of the tube for connection with the tube socket provided at the power generator. Each tube is

capable of producing broadband UVC waveform in the 250-269 nm range. The required quantity and output of the tubes for each air handling plant shall be in accordance with the manufacturer’s recommendation which shall be sufficient to handle the design air flow rate being served.

2.4.7 The power generator of the UV shall be able to operate on 220V/50 Hz single phase supply. It shall generate appropriate supply to match with the operation requirements of the emitter tubes. The power generator shall be equipped with built-in regulator for output adjustment and shall consist of on/off indicator lamp, overload protection device, tube sockets, control knob for regulator setting and on/off switch.

2.5 Lightning Protection System

2.5.1 General

The Contractor shall select, design, supply, install, test and commission the lightning protection system comprising non-radioactive lightning control terminals as shown on the drawings.

The Contractor shall be responsible for the design of the lightning protection system and selection of equipment and components including the matching with other components to ensure that the system conforms with relevant standards such as CP33:1996, BS6651:1992, AS1768:1991, IEC 1024-1:1990 and the specified performance requirements.

The system shall be verified by international recognized laboratory to ensure the system design satisfies the performance requirements.

The Lightning Protection system shall be a specialist design system comprising one or more non-radioactive lightning control terminal(s) connected to the lightning earth pits by a special design co-axial cable as shown on Drawings.

The system shall be designed to have the protection coverage of a minimum of 90% striking frequency with peak current exceed 10 kA level.

2.5.2 Air Termination

The air termination shall be of the type that responds dynamically to the appearance of a lightning downleader by creating free electrons and photo-ionisation between a spherical surface and an earthed central finial. The air termination shall be non-radioactive.

Arcing is not to be continuous and shall only occur during the progress of the lightning leader. Arcing shall not occur solely due to electrostatic field when a thunderstorm is overhead except when there is leader activity in the region.

The external shape of the terminal shall be such as to significantly reduce the build up of sharp point corona discharge under static field thunderstorm conditions.

The air termination shall not be dependent upon batteries or external power supplies for any part of its operation. It shall have no moving parts.

The materials of the air termination shall be non corroding in normal atmosphere. The centre earthed finial shall be at least 300mm² in cross section and be made of electric grade non ferrous material. The outer metallic surfaces of the terminal shall be manufactured of anodised aluminium with spherical dimensions of at least 355mm (dia.), 280mm (h).

The protective zone provided by the air termination shall be such that it becomes the preferred strike point for all discharges exceeding a peak amplitude of lightning stroke current of 6.5KA/10kA/16KA according to the statistical level 98%(high)/ 93% (medium)/85%(standard) respectively of protection required. The design shall take account of upward leader competing projections on the structure.

2.5.3 Air Termination Support

The support shall consist of a minimum of 2 metres of insulating fibreglass cylindrical tube. The tube shall have a minimum wall thickness of 4mm and have such diameter as to allow neat in-line mounting of the terminal. The down conductor shall pass through the centre of the tube.

The support shall be securely bolted to other mast materials with guy wires used where necessary to enable the air termination and mast system to withstand maximum locally recorded wind velocities.

2.5.4 Down conductor

The screened/insulated down conductor shall consist of a plastic filler, copper conductor, inner insulation, outer copper conductor, conductive sheath, all concentrically arranged. The outer diameter of the down conductor shall be less than 37mm.

The main copper conductor shall be made of electrical grade copper of minimum cross sectional area of 50mm². The down conductor shall have maximum characteristic impedance of 8 Ohms and a maximum inductance of 40 nH/m.

The main copper conductor shall be capable of direct connection to the base of the air termination by use of a compression coupling.

The down conductor shall be installed in accordance with the manufacturer's instructions and should not be subject to bends of less than 0.5 metres radius.

The down conductor shall be kept in constant physical contact with the structure via conductive clamps. The top 10% of the installed length from the terminal shall be anchored at least every 1 metre. The lower shall be anchored at least every 2 metres.

Impulse ratings between conductors shall be 200kV, i.e: core - screen 200kV based on 1/50 s wave shape.

2.5.5 Lightning Event Counter

The lightning event counter shall have an electronically controlled mechanical register which activates one registration for every discharge at the point of measurement over 1500A - 8/20s peak current.

The lightning event counter shall be robust, easy to install and housed in IP67 rated enclosure. It requires no batteries or external power source to operate.

The lightning event counter shall be installed to the manufacturer's instructions in a readily accessible manner so that readings can be taken at regular intervals. It shall be positioned such that it’s operating temperature is in the range of -40°C to +50°C.

2.5.6 Grounding

The grounding system reading shall not exceed 10 ohms static impedance except with prior approval by the Architect.

Grounding will be done by copper wire or tape buried not more than 750mm deep or by deep driven copper bonded steel core ground rods especially designed for electrical grounding or a combination of these. In all cases the grounding system shall be electrically connected to the centre ground rod which is securely clamped to the down conductor system.

Bonding of the grounding system to metallic parts of the building, the structural reinforcing steel of the building and to arriving services is recommended. The resistance should be measured and the 10 ohms maximum figure achieved before such bonding is done.

Electrically conductive, non soluble Earth Enhancing Compounds may be used to help achieve low ground resistance provided the materials are mixed and installed strictly in accordance with the manufacturer's instructions.

3. Constraints Applicable to The Installation

The Contractor shall take into account any special noise control requirements in carrying out works in existing premises. Special noise control measures shall be adopted if required. The Contractor shall include in the master programme for Works Order with special noise control requirement.

4. Testing and Commissioning

4.1 Compliance with Testing and Commissioning Procedures

The Contractor shall test and commission the Electrical Installation in compliance Testing & Commissioning Procedures stated in the Preliminaries unless otherwise specified on the Drawings or in this Particular Specification.

4.2 Testing and Commissioning Procedures for Special Items

The Contractor shall propose and submit to the Architect for approval the detailed testing and commissioning procedure for those special installations which are not covered by the G.S. The Contractor shall submit the procedure for testing and commissioning of the following items, if included in the Works Order, to the Architect for approval:

4.2.1 Musical Class Changing Bell System 4.2.2 Stage Lighting System 4.2.3 Nurse/Staff /Emergency Call System 4.2.4 Bedhead Trunking System

4.3 Particular Requirements on Testing and Commissioning Schedules/Sequences

4.3.1 All submissions as required under these procedures are to be submitted to the Architect at least 4 weeks prior to the commencement of testing and commissioning work.

4.3.2 The Contractor shall allow for the attendance on testing and inspection of the Electrical Installation to be conducted by the local electricity supply company so as to ensure that permanent electricity supply will be energized in such good time to the satisfaction of the Architect.

4.3.3 The Contractor shall propose on the minimum operating period of a system prior to full load test to the Architect for approval.

4.4 Others

“Not Used”

5. Maintenance and Training

5.1 Maintenance Requirements

The Contractor shall comply with the maintenance requirement as stipulated in the G.S.

5.2 Training Requirements

Upon request, the Contractor shall provide training on the system operation to the Architect’s representatives and the users at no cost.

5.3 Others

“Not Used”

6. Schedule of Appliance/Equipment Supplied by the Employer

The following appliances / equipment may be supplied by the Employer, but collected, installed and connected as and when required by the Contractor except otherwise specified. The Contractor shall be responsible for the returning of any surplus material to the designated Government / Employer store as and when required.

(a) Battery wall clock (b) Refrigerator (c) Tea urn (d) Radiator/heater (e) Cooker/kettle/dispenser, etc

- PS-35/24 - TC R318