Amendment No1 (nov 2008)

The Electricity Wiring Regulations

Amendment No. 1

Issued by: the Regulation and Supervision Bureau for the Water, Wastewater and Electricity Sector in the Emirate of Abu Dhabi www.rsb.gov.ae

November 2008

Publication No. ED/R01/010 (Rev 1)

Foreword The Regulation and Supervision Bureau for the water, wastewater and electricity sector in the Emirate of Abu Dhabi (the Bureau) issued new Electricity Wiring Regulations in December 2007, covering the design, installation and maintenance of electrical installations in premises. Following implementation of these Regulations and feedback received from building developers, contractors and distribution companies the Bureau has drafted an amendment to the Regulations, referred to as Amendment No. 1 (Nov 2008). This amendment contains a number of clarifications and additional guidance. Two items of particular note relate to the arrangements for RCD protection in Final Distribution Boards (clause 7.8.6) and the method for calculating Diversified Load (clause 3.2.5). The Amendment was published in draft on 10 August 2008 and comments received from interested parties have been considered in detail before preparing the final document. Amendment No. 1 shall be incorporated in the Electricity Wiring Regulations from 1 January 2009, but may be used voluntarily before that date.

Nick Carter Director General 4 November 2008

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Amendment No.1 [Note: new or replaced text is shown in blue. Deleted text is shown as strikethrough. The reason for the change is given in brief in the right margin]

1.2.2

Notes which are included below clauses, in italic text, are not mandatory and are for guidance, clarification or provide supporting technical information.

1.3.8

Relaxation of any of the requirements of the Regulations shall be approved by the Bureau upon written request by any Distribution Company, Customer, property Owner, Licensed Contractor or other person. Such requests may be referred to a dispensation panel established for such purpose by the Bureau.

amended to specify notes to clauses as mandatory

provision for establishing a dispensation panel

2.1.25 Diversified Load: the load at a Distribution Board, at the Supply Intake or at any other point in an Installation, calculated using diversity factors as illustrated in Appendix A20(f) and Guidance Note G2. 3.2.5

The Customer must provide an estimate of the Connected Load at the Premises, including at each Distribution Board. In addition, the Diversified Load for the whole Premises and at each Distribution Board, must be calculated by the Customer’s appointed Licensed Contractor, design engineer or other qualified person and submitted in the format given in Appendix A20(e), see Guidance Note G2.

4.1.10 The maximum three-phase Prospective Fault Current (fault level) for LV supplies shall be 46 kA (1 second) at the LV busbar of the Distribution Company's HV/LV substation …

The Electricity Wiring Regulations - Amendment No. 1 (Nov 2008)

new definition of 'Diversified Load'

addition of term 'Diversified Load'

correction

228

4.2.15 Where a HV/LV substation is required for the supply of Premises ... 5.3.2

Residual Current Devices with a residual current rating of 30 mA and complying with BS EN 61008 and BS 4293 may be used as a means of supplementary protection against Direct Contact. …

[Note: ... It should be noted that earth leakage RCD devices do not protect against electric shock between phase conductors or between phase conductors and neutral.] 5.4.3

5.4.5

RCD devices for Final Circuits must have a time-current performance characteristic complying with BS EN 61008 and BS 4293. … Earth Leakage Protection provided at the Supply Intake must be set to discriminate with ELP devices at Final Circuits (i.e. earth faults on Final Circuits must be automatically disconnected by the closest ELP device, except in the case of back-up operation of devices at the Supply Intake). See Appendix A5(m) and Guidance Note G4(e).

[Note: such discrimination may be provided by time-delayed RCD's, earth fault relays or other suitable devices at each LV panel or circuit breaker at the Supply Intake. ELP is not required at Sub Distribution Boards but, if provided, must discriminate with ELP devices on upstream and downstream Circuits.] 5.4.6

correction

correction

clarification

correction

additional cross-reference

clarification

The operating current setting for ELP devices at the Supply Intake must take into account the nature of the Installation (e.g. commercial, industrial, etc), the likelihood and magnitude of earth fault currents, and the requirement for protection against Indirect Contact, see Appendix A5(m) and Guidance Note G4(f).

[Note: where the Supply Intake consists of a

The Electricity Wiring Regulations - Amendment No. 1 (Nov 2008)

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229

multi-panel LV switchboard, each panel or circuit breaker should be fitted with ELP devices in order to limit the extent of power interruptions. The ELP device for the incomer panel must discriminate with the outgoing panels / circuits.] 5.5.9

5.6.8

Where Circuit conductors are installed close to or within items of metalwork (such as mentioned in clause 5.5.7) ... Water heaters, air conditioning units, fan-coil units, motors and other similar items must be provided with double pole isolation (or 4 pole isolation for 3-phase items) to ensure safe access for the purpose of maintenance and repair.

correction

new clause

[Note: double pole isolation may be provided by a plug and socket-outlet arrangement.] 6.2.1

(b) … The Distribution Company system is earthed at the distribution transformer (11kV/400V) and separate earth and neutral conductors are used …

[Note: these types of earthing systems are illustrated in Appendix A5(a) – A5(c). Earth resistance values of less than 10 Ohms may be specified by the designer for purposes such as Functional Earthing or for specialist installations such as petrol stations, telecommunications sites, etc.] 6.4.3

[Note: where it is proposed to use structural steel or reinforcing steel as an Earth Electrode, suitable testing points must be provided.]

6.6.1

All Exposed-Metallic-Parts of an Installation, including Appliances, must be connected to Earth via Earth Conductors which in accordance with the requirements of Regulation 6.5.

The Electricity Wiring Regulations - Amendment No. 1 (Nov 2008)

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note added

note added

correction

230

6.8.3

6.8.4

Lightning protection systems must be designed, constructed and maintained in accordance with BS 6651 BS EN 62305, except that the lightning protection system is not to be bonded to the Installation Main Earth Terminal. The use of structural steel in place of, or in connection with, lightning down conductors is not permitted unless approved by the Distribution Company. Where such approval is given provision must be made for regular testing of the structural earth system from roof level to ground (e.g. via a separate test cable installed through the building). Structural foundations or piles may be used as lightning earth electrodes if sufficiently separated from the Main Earth Electrodes and where inspection / testing points are provided for future maintenance.

7.1.3

The use of 'Shuko' CEE7/7 2-pin type plugs is strictly prohibited. The use of 'Euro' CEE7/16 plugs is permitted only where used with an approved adaptor converting such plugs for use on BS 1363 type socket-outlets, see Appendix A17(a).

7.1.4

An allowable exception to clause 7.1.1 is the use of shaver supply units in bathrooms, complying with BS 3535. For these types of socket-outlet, which are supplied by a SELV safety isolating transformer, 2-pin unearthed type plugs may be used but which must also comply with BS 3535. See Appendix A17(c).

7.1.7

7.1.9

Socket-outlets for normal use must be positioned at a standard height of 300 mm or 450 mm above floor level or 100 mm above work surfaces, see Appendix A16.

amended to new BS EN standard

new clause

amended to clarify prohibitions

amended to allow the use of CEE7/16 'Euro' plugs in shaver supply units

amended to allow alternative mounting height of socket-outlets

Socket-outlets in kitchens or other areas where water is used must be positioned at least 1.0 m away from sources of water (e.g. sinks, basins,

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filter units, supply taps). Consideration must be given to the use of splash proof socket-outlets (IP 54).

requirement for splash-proof socketoutlets deleted

7.1.14 Outdoor socket-outlets must be of the weather protected type (IP55) and incorporate a 30 mA RCD, see Guidance Note G7(c).

[Note: where a number of outdoor socket-outlets are installed in close proximity, the above requirement may be met by one RCD device serving the group of outlets, provided that the RCD device is readily accessible and visible to persons using the socket-outlets and is clearly labelled.] 7.3.2

7.4.6

The rating of lighting Circuits shall be selected in accordance with the number of connection points to be supplied, the type and rating of luminaires to be used, and the Connected Load for the Circuit. A standard method of calculating Connected Load is given in Guidance Note G2 and illustrated in Appendix A20(f).

note added for groups of outdoor socket outlets protected by one RCD

amended to meet sizing according to Connected Load

Where conduit is buried installed within a wall, floor or ceiling it must be installed at a minimum depth of 50 mm from the surface. If it is installed at a shallower depth then metal conduit must be used. See Guidance Note G7(e).

[Note: for a solid wall, floor or ceiling the above required depth may be reduced to 25 mm for lengths of conduit which are within 4 m of a visible Accessory or connection point, or where the Circuits contained in the conduit are protected by a 30 mA RCD.]

note added to relax depth requirement for buried conduits

7.5.10 The cross-section of cables must be selected according to the expected load, voltage drop, ambient temperature and installation conditions ...

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[Note: the sizing of Final Circuits and Circuits feeding FDBs must be in accordance with the Connected Load. Other Circuits may be sized in accordance with the Diversified Load, with allowance made for future load growth where appropriate. See clause 7.6.1, 7.7.7 and Guidance Note G2.] 7.5.12 Other than as allowed under clause 7.5.15, all cables that are not armoured, or that do not have a metallic sheath or screen, must be installed in plastic or metal conduit or trunking throughout their entire length. 7.6.1

7.7.6

The sizing of Final Circuits must be in accordance with the Connected Load on each Circuit (see Guidance Note G2), whilst taking account of ambient temperature, grouping factors and power factor, see Appendix A7(a) A7(h). Busways, bus ducts and busbar risers shall have neutral conductors of equal size to the phase conductors and shall have a dedicated Earth Conductor. The use of the metal casing as an Earth Conductor shall not be is permitted only for Earth Leakage Protected Installations, and with the prior approval of the Distribution Company.

noted added

amended to allow the use of metallic sheathed or screened cable without conduit

amended to specify sizing according to Connected Load

amended to allow the use of Busways where the metal casing is used as an Earth Conductor

[Note: Aluminium metal casings should be used in preference to steel due to the risk of corrosion and high resistance joints. In either case the sizing of such conductors must meet the values equivalent to copper conductors given in Appendix A5(j).] 7.7.7

The current rating of busways, bus ducts and busbar risers shall be based on the Connected Load Diversified Load of the relevant part of the Installation being supplied, with allowance made for future load growth where appropriate. However, additional diversity factors may be

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applied for high-rise buildings or other large installations rather than taking the sum of Connected Loads. Diversity factors must be justified and submitted with the design for approval by the Distribution Company, see Regulation 3.2 and Guidance Note G2. 7.8.2

Distribution Boards must be of robust construction, capable of withstanding expected electrical, thermal, and environmental stresses in normal service and during faults.

[Note: Final Distribution Boards, including the incoming cable, will normally be rated for the Connected Load of the Circuits supplied; other Distribution Boards and Distribution Circuits may be rated for the Diversified load, using appropriate diversity factors, and with allowance made for future load growth where appropriate. - see Guidance Note G2.] 7.8.6

All Final Distribution Boards must have at least two busbar sections, be arranged so as to provide for at least two zones of Earth Leakage Protection (e.g. 100mA and 30mA) and to avoid complete disconnection of power to the area being served, in the event of an earth fault. This may be achieved by either of the following methods:

note added to clarify rating of Distribution Boards

clarification and note to explain the requirement for two busbar section DBs and alternative arrangements

(a) two or more busbar sections, each protected by an RCD; (b) one busbar section, with individual RCBOs fitted on all Final Circuits (the incomer device may be a time-delayed RCD or an isolator switch where adequate fault protection is provided by an upstream Protective Device); (c) two or more FDBs installed together to serve an area, each having one busbar section protected by an RCD of appropriate rating (e.g. one DB with an incomer 100mA RCD for lighting and another DB with incomer 30mA

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RCD for power circuits)

[Note: either solid busbar or removable ('comb') busbar DB's are acceptable (horizontal or vertical type) if factory assembled and where the manufacturer's type tests are provided. Single phase DBs up to 12 ways, serving a limited area, may be provided with one busbar section, and one incomer RCD of appropriate rating, e.g. hotel rooms, pump room, central a/c room, etc.] 7.8.8

The number of Final Distribution Boards and Sub Distribution Boards provided in a Premises shall take into account the future accessibility, maintainability and safety of the system, whilst limiting the extent of possible power outages to serviced areas.

[Note: to meet the above requirement Final Distribution Boards should be limited to a maximum capacity of 14 ways 3-phase (or 42 ways single phase) and Sub Distribution Boards should be limited to 18 ways 3-phase. 7.8.13 All outgoing circuits of Distribution Boards must be provided with only circuit-breakers (such as CBs, MCBs, MCCBs, RCDs, RCBOs, etc) and shall not contain fuses of any kind, except for capacitor banks. See Regulation 10.2.

[Note: the incoming device of a DB may be an isolator switch, where adequate fault protection is provided by an upstream Protective Device.] 7.8.15 Distribution Boards of rating above 200 A shall be installed in a dedicated room. Distribution Boards of rating 200 A and below may be installed in a cupboard or other suitable enclosure complying with clause 7.8.14 and clause 3.5.9.

clarification to include Sub Distribution Boards clarification

clarification note

amended to allow use of enclosures for small DBs

[Note: Main Distribution Boards of rating 200 A and above must be located in a Supply Intake room, see Appendix A12(b).]

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9.3.2

9.3.2

9.4.1

9.4.1

9.5.1

9.5.1

(a) all Final Circuits must be protected by an RCD of residual current rating 30 mA and complying with BS EN 61008 and BS 4293. Such protection may be grouped across several Circuits at the Final Distribution Board. However, fan-coil units mounted in a ceiling void in a bathroom may be provided with 100mA RCD protection.

Correction

Additional text allowing 100mA RCD protection for FCUs in a bathroom ceiling void

(e) Appliances, Luminares or Accessories which are within Arm's Reach from a bath, shower or similar facility must be supplied by SELV or PELV and have a minimum level of ingress protection of IPX4. Underwater lighting must be supplied by SELV at a maximum voltage of 12 V a.c. or 30 V d.c. and with ingress protection IPX8.

clarification of requirements for ingress protection

(a) all Final Circuits must be protected by an RCD of residual current rating 30 mA and complying with BS EN 61008 and BS 4293. …

correction

(e) Appliances, Luminares or Accessories which are within Arm's Reach from a swimming pool must be supplied by SELV or PELV and have a minimum level of ingress protection of IPX7. Underwater lighting must be supplied by SELV at a maximum voltage of 12 V a.c. or 30 V d.c. and with ingress protection IPX8.

clarification of requirements for ingress protection

(a) all Final Circuits must be protected by an RCD of residual current rating 30 mA and complying with BS EN 61008 and BS 4293. …

correction

(e) Appliances, Luminares or Accessories which are within Arm's Reach from a water fountain must be supplied by SELV or PELV and have a minimum level of ingress protection of IPX7. Underwater lighting must be supplied by SELV at a maximum voltage of 12 V a.c. or 30 V d.c. and with ingress protection IPX8.

clarification of requirements for ingress protection

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APPENDICES A3

Reference standards … continued (p112)

- add row as follows: RCD socket-outlets

A5(j)

added reference standard for RCD socket-outlets

BS EN 7288

Sizing of earth conductors Note 2: Earth Conductors must always be insulated and a cross-sectional area of less than 2 1.5 mm must not be used unless they are an integral part of a sheathed cable (e.g. an Appliance flexible cord).

changed from 2.5mm 2

A5(k) Minimum number of earth electrodes Note 2: Structural foundations of large buildings may be used as Earth Electrodes, see clause 6.4.3 and 6.8.4.

note added

A5(m) Residual operating current settings for RCDs and ELP devices

last row of table: LV main circuit breakers or switchboards (Supply Intake)

See Note 4

Note 2: all Final Circuits in a bathroom (including lighting, but excluding FCUs in the ceiling void) must be provided with 30 mA RCD protection. See clause 9.3.2(a).

clarification for discrimination of protection

additional notes added

Note 3: where a circuit supplies more than one type of equipment the lower value must be used for RCD protection (e.g. a circuit supplying bedroom lighting and bathroom lighting must be protected by a 30 mA RCD). Note 4: the selection of ELP devices at main switchboards must take into account the

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requirement for discrimination with downstream protective devices (clause 5.4.5 and 5.4.6). For small supplies (200A or less) a 300mA RCD device may be used, with time delay of 200ms. For larger supplies (above 200A) earth fault relays may be used in conjunction with MCCBs (e.g. 1A, 3A, 5A with time delay up to 400ms) or ACBs with integral earth fault setting. In the latter case the earth fault setting must trip the ACB within 400ms, taking into account the Earth Fault Loop Impedance of the installation.

A6(f)

MCBs selection criteria

amend row 4 and 5 as follows: MCB rating

Cable size 2 mm

Cable rating at o 30 C

Cable rating at o 40 C

20

4.0

32 (6.3)

27.8 (5.4)

Radial Circuit to fixed appliances (e.g. a/c unit)

32

2 x 4.0

48 (9.3)

41.7 (8.1)

Ring Circuit to socket-outlets

Typical applications

Note 1: cable ratings are taken from Appendix A7(a), assuming one circuit in conduit, with temperature correction factors applied from Appendix A7(g). Power factor of 0.85 is assumed to calculate kW ratings at 230V.

amended to allow 2 2 x 4mm conductors instead 2 of 6mm

clarification notes added

Note 2: selection of MCBs for overload protection of cables must take account of the device characteristics given in Appendix A6(b) to A6(d). These are based on minimum MCB operating currents of 1.45 times the MCB nominal rating (In) and a maximum 'non-tripping' current of 1.15 times In. Hence, cables must be selected with ratings at least 1.15 times the MCB nominal rating (see IEE Guidance Note 6 - section 2).

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A12(b) Diagram: Typical layout of supply intake room

- amend table as follows: Main circuit breaker rating (A)

Intake room dimensions (m)

1600 - 2500

3.5 x 3.5

1000 - 1200

3.0 x 3.0

600 - 800

2.5 x 2.5

400 - 500

2.5 x 2.0

200 - 300

2.0 x 2.0

Note 1: the above rooms sizes are given for guidance and other requirements for access and safety should be taken into account (see Regulation 3.5)

amended to specify dimensions of supply intake rooms

note added

A12(c) Typical layout of final distribution board

- amend drawing to show 2-section busbar A12(d) Typical layout of LV switchroom

- amend drawing (outgoing circuits should be above panels 2 and 3) A14

correction

correction

Diagram: Typical layout for ring circuit and radial circuits

- amend to show 2 or more 15A socket-outlets - remove joint on spur socket-outlet

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239

A15

Minimum number connection points Room

of

socket-outlets

and

Minimum number of outlets for domestic premises

Kitchen: 13A socket-outlets (worktops)

Minimum 2 double, plus every 2 m of worktop

13A socket-outlets (Appliances)

Minimum 1 single, plus as required for free standing Appliances (e.g. fridge)

20A spur Connection points for washing machine, dryer, etc

Minimum 1, plus as required for number of items installed (flex outlets or socket-outlets)

45A Cooker control unit

1

Bedrooms

2 double, 1 single

Lounge or dining

3 double, 1 single

Hall or corridor

1 single

Bathrooms

amended to cater for various sizes of kitchens

adjusted to provide for safety and convenience

only BS 3535 shaver socket (if required)

Note 1: in general, double socket-outlets should be used in preference to single socket-outlets wherever possible

notes added for clarification

Note 2: socket-outlets should be conveniently located to avoid the need for extension cables and adapters (which introduce risk of overheating and fire) Note 3: 15A BS 546 socket-outlets are not permitted in domestic premises (see clause 7.1.1)

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Note 4: the maximum number of socket-outlets on a Circuit is not limited and is dependent on the load supplied and the wire size (see Appendix A6(f) and Guidance Note G2)

A16

Diagram: Mounting height for accessories and socket-outlets

correction

- amend to show double socket-outlets

A19(g) Sequence of testing for new installations Note 2: testing of RCDs must include measurement of the operating time (ms) at In and at 5 x In, as well as check of non-operation at 50% x In.

new note added

A19(h) Additional test procedures - additional test procedures to be added for RCDs and ring circuits

addition

A20(a) Electrical installation certificate add "Total Diversified Load", in row 3

addition of term ’Diversified Load’

A20(b) Inspection report add "Total Diversified Load", in row 3 A20(e) Load Distribution Schedule

- see last page

A20(f) Load Distribution Schedule - example

- see last page

G1

addition of term ’Diversified Load’ amended to show calculation of diversified load

example added showing calculation of diversified load

Guidance note on supply voltage change … the UK has adopted a supply voltage of 230 / 400 V

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G2

Estimation of Connected Load and Diversity Factors

- amended to reflect realistic Circuit ratings (Connected Load) and typical Diversity Factors Estimation of Connected Load and Diversified Load for domestic premises Type of load

Connected load [see note 1]

Typical diversity factor [see notes 3 and 7]

Lighting

•

• • 13A socket-outlets

•

sum of wattage of all luminaries or assume 100W for each lighting point (except chandelier points) chandelier lighting points – 500W 1.8 x lamp wattage for fluorescent lighting

75%

1,000 W for first socket-outlet plus 200 W for remainder socket-outlets (including kitchen ring circuits),

50%

[see note 2]

Kitchen power points

•

• • Other power points

• •

Air conditioning

• • •

kitchen appliance connection points assume 1,500 W each or actual rating of appliance (e.g. washing machine, dryer, dish washer etc) cooker – assume 3,000 W or actual rating of oven plus the largest ring fridge – assume 300 W or actual rating

50%

water heater – 1,500 W or actual rating motors (e.g. lifts) – actual rating

50%

split air conditioning units – full rating window air conditioning units – full rating central a/c units (see note 5)

90%

- page 195 text deleted and replaced with the following notes: Note 1: the Connected Load values shown above are based on typical Appliances and connection

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242

points. Specific site information should be used where available. Note 2: the Connected Load (and cable rating) for Circuits supplying socket-outlets should be based on 1,000 W for the first socket-outlet, plus 200 W for the remainder, where a double socket outlet is counted as 2 (e.g. circuit rating for 5 x double socket-outlets = 1kW + 9 x 0.2kW = 2.8kW). Note 3: typical diversity factors for domestic premises are shown above but the designer may select a different value representing the intensity of usage (e.g. higher value for high usage Circuits, such as communal kitchens, lower value for lower occupancy dwellings, etc) Note 4: additional diversity factors may be applied at Sub Distribution Boards and Main Distribution Boards, typically 0.9. Hence, the expected demand at the Supply Intake may be 0.81 times the sum of the FDB Diversified Loads. Note 5: a 90% diversity factor may be applied for split or window type air conditioning units; diversity factors for central a/c units should be based on manufacturers data or load data taken from other similar installations (during summer temperature conditions) Note 6: The calculated Diversified Load for Premises should be checked against electricity usage data for similar Premises (typically 30 - 80 W / sq m for domestic Premises and 100 – 150 W / sq m for offices and shops, including air conditioning). Note 7: for non-domestic Premises an assessment of diversity factors must be made by a qualified designer or engineer with knowledge of the proposed usage of the Installation. For offices and shops diversity factors of 80% – 90% may be typical for lighting and power Circuits. However, for industrial equipment (e.g. machinery, water pumps, etc) diversity factors may range from 20% to 100%, depending on the operating cycle of the equipment.

The Electricity Wiring Regulations - Amendment No. 1 (Nov 2008)

revised calculation of Connected Load for socket-outlet Circuits

selection of appropriate diversity factors

diversity factors for Main and Sub Distribution Boards

correction

check of diversified load vs. floor area

assessment of diversified load for non-domestic Premises

243

G5(a)

RCD operating characteristics and electric shock … This is normally achieved with RCD devices complying with BS EN 61008 and BS 4293. …

G7(c)

correction

Weather protected outdoor socket-outlets diagram note: IP66 IP55 weather protected socket-outlet with 30mA RCD

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correction

244

Appendix A20(e) Load Distribution Schedule Project / Building Name:

............................................................. Main Contractor: ............................................................. Electrical Contractor: ............................................................. Incoming Cable size / type: ............................................................. Main breaker type & rating:

Address / Location:

Incomer

Distribution Board No. / Ref. Fed from: Busbar section / RCD

CCT ref. No.

MCB rating (A)

Phase & Neutral Size mm2

Earth size mm2

Cable rating A (kW) [see notes]

............................................................. ............................................................. ............................................................. .............................................................

Circuit name / Point reference

No. of points (double / single)

Date: Document No.

Connected Load per point (kW)

........................ .......................

Circuit Load (kW) R

Y

B

Diversity factors

Circuit load after diversity (kW)

R1

............................

Section 1 ...........

Y1 B1 R2 Y2 B2 R3 Y3 B3 R4

Section 2 .............

Y4 B4 R5 Y5 B5 R6 R7 R8 GROSS FLOOR = ........ sq m

TOTAL CONNECTED LOAD = ...... kW

FLOOR AREA DIVERSIFIED LOAD = ...... W / sq m

TOTAL DIVERSIFIED LOAD = ...... kW (%)

Notes:

1. Cable ratings taken at xx oC and xx power factor, installed as single circuits in conduit 2. Cable rating must be above circuit Connected Load and at least 1.15 times MCB nominal rating

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Appendix A20(f) Load Distribution Schedule - sample Project / Building Name:

Mr Mubarak Al Hosni Villas Sector ME-10 Plot C-96, Abu Dhabi FDB-2 second floor apartment......... MDB-1 (intake room).......................

Address / Location: Distribution Board No. / Ref. Busbar section / RCD

Section 2 30mA RCD 40A 3ph

63A isolator 3ph

Section 1 100mA RCD 40A 3ph

Incomer

Fed from: CCT ref. No.

MCB rating (A)

Phase & Neutral Size mm2

Earth size mm2

Cable rating A (kW) [see notes]

Main Contractor:

Sedmand Construction LLC......... Al Ramal EC ................................. Incoming Cable size / type: 4C x 16mm XLPE with SWA-earth…....................... Main breaker type & rating: 63A isolator + 2 RCD (see below)…......................

Electrical Contractor:

Circuit name / Point reference

No. of points (double / single)

Date: Document No. Circuit Load (kW)

Connected Load per point (kW)

R

1.0

R1

6

1.5

1.5

17.5 (3.4)

Lighting, bedrooms 1, 2, 3

10

0.1

Y1

6

1.5

1.5

17.5 (3.4)

Lighting (fluorescent) - kitchen

10

0.05

B1

6

1.5

1.5

17.5 (3.4)

Lighting - lounge (inc. chandelier 500W)

11

0.1/0.5

R2

6

1.5

1.5

17.5 (3.4)

Smoke detectors

3

0.02

Y2

10

2.5

1.5

24.0 (4.7)

FCU-1, FCU-2, FCU-3

3

0.6

B2

10

2.5

1.5

24.0 (4.7)

FCU-4

1

1.6

R3

32

6.0

2.5

41.0 (8.0)

Cooker

1

3.0

3.0

1.5

Y3

spare

B3

spare

R4

16

2.5

1.5

24.0 (4.7)

Water heater: kitchen

1

1.5

Y4

16

2.5

1.5

24.0 (4.7)

Water heater: bathrooms 1 and 2

2

1.2

B4

6

1.5

1.5

17.5 (3.4)

Lighting (fl) + shaver socket - bathrooms 1, 2

6

0.05

R5

32

2 x 4.0

2 x 2.5

48.0 (9.3)

Socket-outlets - kitchen ring (inc. fridge)

3d + 1s

1.0 / 0.2

Y5

16

2.5

1.5

24.0 (4.7)

Socket-outlets: maid's room + corridor

1d + 2s

1.0 / 0.2

B5

20

4.0

2.5

32.0 (6.3)

Flex-outlets - dishwasher, dryer

2

1.5

R6

16

2.5

1.5

24.0 (4.7)

Flex outlet – washing machine

1

1.5

R7

32

2 x 2.5

2 x 1.5

36.0 (7.0)

Socket-outlets (ring) - lounge

4d + 3s

1.0 / 0.2

R8

32

2 x 4.0

2 x 2.5

48.0 (9.3)

Socket-outlets (ring) - bedrooms 1, 2, 3

8d + 3s

1.0 / 0.2

GROSS FLOOR = 200 sq m

TOTAL CONNECTED LOAD = 29.6 kW

FLOOR AREA DIVERSIFIED LOAD = 85 W / sq m

TOTAL DIVERSIFIED LOAD = 17.0 (57%)

Notes:

4-7-08 ARE-34-8.

Y

B

0.50 1.5 0.06 1.8 1.6

2.4 0.3 2.2 1.6 3.0 1.5 3.0 4.6 9.3

9.3

Diversity factors

Circuit load after diversity (kW)

0.75

0.75

0.75

0.38

0.75

1.13

1.0

0.06

0.9

1.62

0.9

1.44

0.5

1.50

0.5

0.75

0.5

1.20

0.75

0.23

0.5

1.10

0.5

0.80

0.5

1.50

0.5

0.75

0.5

1.50

0.5

2.30

11.0 17.0 kW

1. Cable ratings taken at 30oC and 0.85 power factor, installed as single circuits in conduit 2. Cable rating must be above circuit Connected Load and at least 1.15 times MCB nominal rating

The Electricity Wiring Regulations - Amendment No. 1 (Nov 2008)

246