Completion .1 Commissioning

Mains supply

Before commissioning, ensure mains supply has been continuously connected for at least 24 hours.

11.4.2 Completion Tests General

As per the clause 8 and section 12.4 of BS5266, the complete emergency lighting installation including individual light fixtures should be tested and records should be maintained.

Daily Tests:

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Any fault recorded in the log book has been given urgent attention and action noted.

Monthly Tests:

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Each luminaire is tested by stimulating a mains failure and switching the system or the light into battery operation.

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All light fittings should be visually inspected, unless the system is addressable in nature.

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All charger / Control devices / battery should be visually inspected.

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All faulty lamps / charger / control devices / battery etc should be replaced and the system put into complete normal operation.

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Records should be maintained.

Yearly Tests:

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Rated life of the battery must be verified and all battery units must be replaced with new units if required.

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A measurement of emergency illumination is carried out randomly on the premises.

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Records should be maintained.

11.4.3 Maintenance General

Carry out the 6-monthly procedures.

12 EARTHING

12.1 General

12.1.1 Cross References General

Comply with the General services requirements section.

12.1.2 Standards General

BS 7430 Code of Practice for Earthing

BS 7671 Requirements for Electrical Installations

IEC Earthing arrangement and protective conductors.

EVN Regulation

12.2 Quality

12.2.1 Submissions Shop drawings

Submit layout drawings of the earthing system showing the following information:

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Earth Bar Details

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Earth Electrode Details

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Exact routing of all main earth loops.

Test results

Earth electrode resistance test results.

12.3 Components

12.3.1 General

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Every means of earthing and every protective conductor shall be selected and erected to satisfy the requirements of the listed standards.

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The cross-sectional area of every protective conductor shall be as per IEE Wiring Regulations and telecommunications authority regulation.

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All switchboards, motor control centers, motor starter panels, and final distribution boards shall have a copper earth bar to which shall be connected the earth conductor of the equipment.

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Main equipotential bonding conductors shall connect to the main earthing terminal for that installation extraneous conductive parts including: main water pipes, main gas pipes, other devices pipes and ducting, risers of air conditioning systems, and metallic parts of the building structures.

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Local supplementary bonding connections shall be made to metal parts where those parts are extraneous conductive parts and are simultaneously accessible with exposed conductive parts or other extraneous parts and where local equipotential bonding is provided Metalwork which may be required to be bonded includes baths, metal pipes, switches and taps.

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An earth rod for main telecommunication room must be provided at the entry box. The required earth resistance should not exceed more than 5 ohms

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The main telecommunication room must be provided with a good earth set with resistance of less than 1 ohms.

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Any metal parts in telecommunication room must be earthed / earth bonded in accordance with the manufacture’s guidelines and safety standards

12.3.2 Earth Electrode

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Earth Electrode will normally comprise of 16 mm diameter steel-cored copper rods driven to a minimum depth of 3m. The tap of each Earth Electrode must be housed inside a 300 mm x 300mm x 300mm inspection pit which is clearly labelled and accessible for routine testing. Alternative types of Earth Electrode may be used with prior approval of the Distribution Company (e.g. plate or wire mesh type, or structural steelwork in a building).

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Earth Electrode can alternatively by the building structural pile.

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Where more than one Earth Electrode is required to achieve the required Earth Resistance value these must be separated at a distance greater than their mutual resistance zone.

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For long terms performance of Earth Electrode, proprietary chemical or salt materials may be used around the Earth Electrode to maintain moisture content but these must be stable and sustain their chemical properties over time.

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For supplies of 500 A rating and above, at least two independent Earth Electrode must be provided, regardless of the Resistance Value achieved for each Earth Electrode, and connected to the same Main Earth Terminal.

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Metallic service pipes (such as water, gas, etc.) must not be used as Earth Electrodes.

12.3.3 Earth Bar

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Earth bar with enough number of ways and mounted on high impact uPVC channel with disconnecting link shall be provided on the wall of each electrical, plant rooms and connect to the enclosure and ground buses of all equipment in the room. Unless otherwise specified, 650mm long and 90mm width earth bar shall be provided, as minimum.

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Earthing clamp shall be used to connect the earth electrode to the earth bars with PVC earthing cables.

12.3.4 Earth conductors

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All earthing conductors shall be copper conductor material only. Material shall be in conformity with the codes and standards.

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All Earth Conductors must be covered with green/yellow PVC insulation and terminated with purpose made lugs or fixings.

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Where associated with Circuits, all Earth Conductors must be labelled at their termination points with Circuit identification numbers.

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The connection of Earth Conductors to Earth Electrodes must be made using corrosion resistant clamps.

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Where earth conductors are buried below ground they must be mechanically protected.

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All circuit must have a Circuit Earth Conductor size in accordance with Electricity Wiring Regulation.

Circuit Earth Conductors must, where practicable, run alongside the associated phase and neutral conductors.

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For metal sheathed or armoured cables, the sheath or armouring may be used as the Earth Conductor where it is rated to the equivalent of the conductor size required in accordance with Electricity Wiring Regulation. The metal sheath or armouring must be terminated by suitable cable glands with

appropriate connection to an Earth Conductor. However, where such cables are installed underground a separate Earth Conductor must be laid alongside the power cables.

12.3.5 Joints General

All crossing of conductors in the main earth grid should be joined. Compression type joints may be used for stranded conductors & when compressed firmly onto its associated conductor the joint should conform to BS 3288-1.

No conductor strip should be drilled for a bolt having a diameter greater than one third of the width of the strip. If this diameter would be exceeded then a flat should be jointed to the strip.

The following methods have been found to be satisfactory:

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Brazing using zinc free brazing material with a melting point of at least 600 degree C.;

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^Bolting;

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Riveting & sweating;

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Thermic welding;

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Cold pressure welding.

12.3.6 Ground Enhancement Material Maintenance Free (no salt recharging required) Non-polluting to soil and water table

Function: Independent of continuous water presence Resistivity: <20 ohm-cm

In document 01. Electrical Tech Spec (Page 100-104)