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and Electricity Intak
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4.2.7 The Electricity Intake must not be located on the reverse side of a bathroom or kitchen wall, or below a bathroom or kitchen. The Electricity Intake must not be located below any water services or pipes, such as mains water supply, drainage systems, storage tanks, air conditioning chillers, or other liquids or hazardous materials.
4.2.8 The Electricity Intake room must be well ventilated, preferably without the need for forced air circulation. Where air conditioning is required in the Electricity Intake room, the requirement for fresh air circulation must also be provided to avoid condensation.
[Note: consideration must be given to the relevant UAE fire code requirements.]
4.2.9 At least one emergency lighting unit must be fitted in all Electricity Intake rooms, which must be provided with a battery rated for minimum 3 hours illumination, and subject to adequate routine maintenance.
4.2.10 Doors to Electricity Intake rooms must be arranged to open outwards, be kept free from obstructions, and be capable of being opened from the inside without the use of a key. 4.2.11 The need for delivery of heavy equipment to the Electricity
Intake room during construction and for future repair or alterations must be taken into account in the location of the Electricity Intake room.
4.2.12 For Electricity Intake rooms greater than 6 m in length, more than one door shall be provided as a means of emergency access.
4.2.13 Electrical Installation layouts and minimum sizes of the Electricity Intake are given in Appendix A12(b) and A12(d). 4.2.14 For large Electrical Installations, the Electricity Intake may contain one or more LV switchboards, the requirements for which are given in Regulation 7.9.
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4.2.15 Where a HV/LV substation is required within the Premises, the design and construction requirements for the substation will be specified by the Distribution Company.
4.3
The Connection Point
4.3.1 Equipment at the Connection Point must be locked or sealed by the Distribution Company to prevent deliberate or accidental interference. Such locks or seals will include those for metering equipment, etc.
4.3.2 The Owners’ Main Distribution Board must always include a means of emergency isolation in the case of a fault or breakdown (e.g. main circuit-breaker) which is readily accessible and clearly labelled so as to be easily operated by the Owner. Such means of emergency isolation must be left unlocked at all times, except when locked in the open position to allow access to the Electrical Installation (e.g. for maintenance).
4.4
Multiple occupancy Premises
4.4.1 Individual Customers within multiple occupancy Premises may be supplied by the Premises Owner’s Electrical Installation consisting of rising and lateral mains (cabling or busbars). Rising and lateral mains will normally be owned and operated by the Premises Owner.
4.4.2 The electricity metering for individual Customers for a rising or lateral mains system will normally be at the point nearest to each Customer, remote from the main Electricity Intake.
4.5
Metering requirements
4.5.1 The requirements for Customer metering are contained in the Customer Metering Regulations, issued by the Bureau. Additional detailed requirements and procedures will be provided by the Distribution Company where required.
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5.1
General principles
5.1.1 All Electrical Installations and individual Circuits therein must be designed, constructed and maintained to provide protection against the following:
(a) overload;
(b) short-circuits (phase to phase or phase to Earth); and
(c) electric shock (due to Direct or Indirect Contact with electricity).
5.1.2 Protection against conditions of overload and short-circuit will normally be provided by MCBs, MCCBs or similar devices, see Regulation 5.2 below.
5.1.3 Protection of persons against electric shock due to Direct Contact or Indirect Contact must be provided by one of the methods detailed in Regulation 5.3 below.
[Note: see Guidance note G4(a) and G4(b) for explanation of Direct and Indirect Contact.]
5.2
Overload and short-circuit protection
5.2.1 All Electrical Installations and individual Circuits therein must be provided with devices that protect against thermal, electromagnetic and other detrimental effects caused by overload and short-circuits. Such devices must be located at suitable sections and Circuits so as to give effective automatic disconnection in such conditions.
5.2.2 The main circuit-breaker at the Connection Point must be of MCCB or ACB type and adequately rated for the maximum Prospective Fault Current.
5.2.3 All Circuits must be individually protected against overloads and short-circuits by suitable devices. Replaceable or re-wireable fuse links are not permitted for this purpose.
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5.2.4 The time-current performance characteristics of Protective Devices must conform to the relevant reference standards listed in Appendix A3.
[Note: the time-current performance curves for MCBs are shown in Appendix A6(a) – (d).]
5.2.5 To ensure protection against overload, Circuit conductors must be sized taking into account the time-current characteristic of the Protective Device.
[Note: see note 2 of Appendix A6(f).]
5.2.6 Protective Devices at the Main Distribution Board must have a Prospective Fault Current withstand and interruption rating above the maximum Prospective Fault Current declared by the Distribution Company for the relevant Connection Point.
5.2.7 Protective Devices downstream of the Main Distribution Board may have a reduced Prospective Fault Current withstand and interruption rating, taking into account the ‘energy let-through’ characteristic (I2t) of the upstream
Protective Device, see Appendix A6(e). Where appropriate, an allowance may also be made for the attenuation of Prospective Fault Current due to the Circuit impedance.
5.3
Electric shock protection
Direct Contact
5.3.1 Protection of persons against the risk of Direct Contact with electricity must be provided by either physically preventing contact or by an inherently safe systems of supply, using one or more of the following measures:
(a) insulated conductors, see Regulation 5.7;
(b) secure enclosures, barriers or covers on live parts; (c) Separate Extra-Low Voltage (SELV) system; or (d) Protective Extra-Low Voltage (PELV) system.