Dubai Building Code (2021)

Dubai Building Code

Part G: Incoming utilities

G 17

G.4.4

Point of Supply

G.4.4.1

General

Point of supply shall be made available at one location

within a plot/project, unless otherwise approved by

DEWA. The point of supply defines the boundary of

DEWA equipment, and shall be decided by DEWA.
The circuit breaker(s) and/or main distribution

board (MDB) provided at the point of supply shall be

designed and rated to suit the required application, and

to conform to all applicable requirements of G.4 to G.7.
The main circuit breaker at the point of supply

(see Figure G.1) shall be marked as such and shall be

identifiable from other breakers for easy operation in

an emergency. Where more than one incoming supply

is available, in any premises, each main circuit breaker

shall be marked to indicate which installation, or

section of the installation, it controls.

Where a main low voltage (LV) distribution panel is

connected directly to the LV side of the transformer,

the main incomer circuit breaker proposed in the LV

panel shall be a fully withdrawable four-pole type air

circuit breaker (ACB) (see Figure G.2).
Where the consumer’s main LV distribution board

(DB)/panel is connected to DEWA’s two or more

distribution transformers, separate bus-sections with

mechanically and electrically interlocked bus-section

breakers/isolators (four-pole) shall be provided.

Figure G.1

Main circuit breaker

Figure G.2

Typical fully withdrawable four-pole circuit breaker

All incoming cable terminations/live connections in

metering cabinets, MDBs and sub-main distribution

boards (SMDBs) shall be shrouded and insulated.
All exposed live terminal connections and busbars in

any LV DB shall be shrouded and/or insulated.

Dubai Building Code

Part G: Incoming utilities

G 18

G.4.4.2

Switchgear locations

The main electrical switchroom shall be located near

to the plot entrance, on the ground floor. Where a

substation is provided within the building, the main

electrical switchroom shall be provided in the ground

floor area adjacent to the transformer room.
The consumer’s MDBs, SMDBs and final DBs shall

all be installed in locations to which access is always

available. The minimum dimensions for safe access

shall be in accordance with Figure G.3.
The mounting height [to the top of the board(s)] shall

normally be 2 m from the ground/floor level.

All main electrical switchrooms, and other sub-

electrical switchrooms in which capacitor banks are

installed, shall be air-conditioned. Non-air-conditioned

electrical rooms shall be ventilated and provided with

heavy duty exhaust fans and metallic louvered doors,

as applicable.

As required by Table 1.9, Ch. 1 of UAE FLSC

[Ref. G.1]

interior electrical rooms shall be separated from the

rest of the building by a 2 h fire rated enclosure. If the

access door to the room opens to the exterior then it

can be louvered. Where the access door opens to the

interior of the building it shall be 90 min fire rated

without louvers.

Figure G.3 Layout of main electrical switchroom with one cubicle type LV switchboard/panel

Key

01: LV switchboard/panel

02: Capacitor bank

03: SMDB (sample)

04: kWh meters

05: Non-maintained, minimum

3 h rated, self-contained

emergency light

06: Light fitting

07: Non-combustible door in

an exterior wall and 90 min

fire resistance rated, non-

combustible, non-louvered door

in an interior wall

NOTE: The minimum clear space

shown at the sides and rear of

the panel is for switchboards

with rear access requirements

only.

An adequate level of illumination shall be provided to

facilitate safe operation at all times. All electrical rooms

shall be provided with non-maintained emergency

lighting in accordance with Ch. 6 of UAE FLSC

[Ref. G.1]

Door openings to electrical switchrooms shall meet the

following requirements.
a) The door shall open outwards in the direction of

egress.

b) The opening shall be kept free from obstructions.
c) The door shall not open towards a driveway,

staircases and steps, or other areas of people or

traffic movement.

1,500

Dubai Building Code

Part G: Incoming utilities

G 19

A minimum illumination of 500 lux shall be provided to

facilitate safe operation at all times.
Incoming supply cables to the consumer’s MDB(s)

shall be completely segregated and identified from the

consumer’s cables.
Electrical switchrooms shall not be located below or

beside the following wet areas:
1)  bathrooms;
2)  toilets;
3)  kitchens;
4)  pantries;
5)  storage tanks;
6)  air conditioning chillers or other liquid/hazardous

materials.

Water pipes shall not be installed within or on electrical

switchroom walls.

G.4.4.3

Main electrical switchroom

The dimensional layout of electrical switchrooms shall

be maintained as shown in Figure G.3 for a single LV

panel, Figure G.4 for switchrooms containing two

freestanding LV panels or Figure G.5 for switchrooms

containing wall mounted LV panels. The electrical

switchroom shall not be used for storage of any

equipment, material, etc.

Figure G.4 Layout of main electrical switchroom with two cubicle type switchboards/panels

NOTE: The minimum clear space shown at the sides and rear of the panel is for switchboards with rear access

requirements only.

Key

01: LV switchboard/panel

02: Capacitor bank

03: SMDB (sample)

04: kWh meters

05: Non-maintained, minimum

3 h rated, self-contained

emergency light

06: Light fitting

07: Non-combustible door in

an exterior wall and 90 min

fire resistance rated, non-

combustible, non-louvered door

in an interior wall

As required by Table 1.9, Ch. 1 of UAE FLSC

[Ref. G.1]

interior electrical rooms shall be separated from the

rest of the building by a 2 h fire rated enclosure. If the

access door to the room opens to the exterior then it

can be louvered. Where the access door opens to the

interior of the building it shall be 90 min fire rated

without louvers.

1,200

1,500

Dubai Building Code

Part G: Incoming utilities

G 21

Figure G.6

Typical arrangement for tariff metering cabinet recessed within compound wall

G.4.5

Tariff metering

G.4.5.1

Individual consumer premises

Individual consumer premises include villas, farms,

gardens and accommodation blocks. The metering

cabinet (including main incomer circuit breaker) in such

premises shall be installed in the compound wall as

illustrated in Figure G.6.

A minimum clearance of 2 m shall be maintained

between electricity and water service cabinets/points.

For CT operated meters, VT fuses shall be sealed type,

located in a sealable enclosure.

Key

01: Compound wall

02: Weatherproof (IP 55)

metering cabinet

03: Hinged door with provision

for wire sealing and pad locking

(hole size: min. 10 mm diameter)

04: Cable (gland) box

05: Transparent meter viewing

window (min. 5 mm thickness,

size: 150 mm × 150 mm)

06: Protection cover with hinges

on top (size: 200 mm × 200 mm)

07: Position of incomer breaker

08: 150/100 mm PVC pipe

sleeve for service cable

09: Conduit/s for earthing

conductors (ECC)

Type of kWh metering

Dimensions (mm)

Direct connected metering

(Up to 125 A)

600

800

250

200

800

(min.)

1,600

(max.)

1,800

(max.)

CT. Operated metering

(5 A meter and CT ratio up

to 400/5 A)

800 1,000 300

250

800

(min.)

1,600

(max.)

1,800

(max.)

Dubai Building Code

Part G: Incoming utilities

G 22

G.4.5.2

Multiple consumer premises

Multiple consumer premises include residential/

commercial buildings, industries, large utility complexes

and schools. The MDBs and SMDBs, with associated

metering, shall be installed in separate electrical

switchrooms. Switchrooms shall be located close to the

entrance boundary line. Access shall be available at all

times for operation, testing, inspection, maintenance

and repair.

For all buildings having a cooling load of at least 1 MW,

or a gross floor area of 1,000 m

or greater, additional

electrical submetering (of tariff class accuracy) shall

be installed. The submetering shall record demand and

consumption data for each energy-consuming system

in the building with a load of 100 kW or greater.
All tariff metering shall be smart meters, normally

provided by DEWA and restricted to one for each

consumer installation, unless otherwise approved/

specified by DEWA.

G.4.5.3

Metering cabinet arrangement

The minimum space provided for installation of a kWh

meter shall be 300 mm wide and 500 mm high

(see Figure G.7). A minimum space of 1,200 mm shall

be provided in the front of kWh meter cabinet/meters.
The general arrangement and dimensional layout of

the metering cabinets and array of meters installed

in electrical switchrooms and enclosures, along with

associated wiring, shall be submitted to DEWA for

approval.

A minimum 2 m clearance shall be maintained between

electrical and water service.

The following typical arrangements of kWh metering

cabinets/kWh meters are given for guidance:
a)

multi-tenant arrangements (see Figure G.7);

single-tenant arrangements (see Figure G.8).

Figure G.7

Typical multi-tenant metering arrangement

Key

01: MDB/SMDB

02: PVC/GS trunking

03: Non-combustible type

board/plate for fixing kWh

meters

04: kWh meter

05: Supply cables

NOTE 1: Layout indicates the

minimum space, maximum

number of rows and

arrangement of kWh meters.
NOTE 2: Earthing details,

outgoing circuits and conduits

terminations are not indicated.

Dimensions (mm)

1,800

600 (min)

500

100

300

Dubai Building Code

Part G: Incoming utilities

G 23

Figure G.8 Arrangement of metering in main LV panel

Key

A: CT operated, kWh metering

compartment

B: Transparent viewing window for

meter (size: 1.25 m × 1.25 m)

C: Protection cover with hinges on top

(size: 1.5 m × 1.5 m)

D: Three sealable type VT fuse

carriers in sealable enclosure for data

concentrator

E: kWh meter

F: Pad locking arrangement (hole size:

10 mm diameter)

G: CT shorting terminal block in

sealable enclosure (RS1 and

RS2/YS1 and YS2/BS1 and BS2)

01: Load side busbars (400 mm)

02: Metering

03: Main incomer and CTs

04: Main cable terminal

05: 20 mm conduit from the kWh

metering compartment to the cable

trench

For CT operated meters and data concentrators,

VT fuses shall be sealed type, located in a sealable

enclosure.
To facilitate meter reading, a transparent viewing

window shall be provided in all metering cabinets,

and in doors of enclosures housing the meters with

associated distribution switchgear (see Figure G.8,

item B). The material used for the viewing window shall

be not less than 5 mm thick. The window shall have a

hinged type protection cover.
All metering cabinets and enclosures shall be

constructed from non-combustible material.
When meters are installed in electrical switchrooms,

fire-resistant/non-combustible base plates shall be

provided. Single core PVC or XLPE insulated and PVC

sheathed cables conforming to BS 6004 shall be used

for connection to kWh meters.
All metering cabinets/compartments shall be provided

with padlocking and wire sealing facilities on their

external door/cover, which shall normally be hinged

(see Figure G.9). Generally, all apparatus, circuit

breakers, isolators, busbars, removable lid section of

busbar - trunking, etc., installed on the supply side of

any DEWA’s metering shall have provision for sealing

by DEWA.

C
D

Dubai Building Code

Part G: Incoming utilities

G 24

Figure G.9

Typical metering cabinet padlocking and wire tag

The metering section/compartment in all MDBs and

SMDBs, if and when incorporated within, shall be

segregated from other sections/compartments.

For consumer premises with groups of villas,

space/provision shall be made for installing DEWA

feeder pillars. The location of such feeder pillars shall

be finalized during estimation taking into account the

cable route, cable route length, road crossing, etc.

G.4.5.4

CT metering requirements

Metering by means of current transformers (CTs) shall

be installed where the circuit breaker rating at the

point of supply is 160 A and above.

NOTE 1: DEWA provides the smart kWh meter(s)

and associated CTs for all tariff metering. In some

circumstances the consumer might be permitted

to provide the kWh meter and CTs as private check

meters for energy monitoring purposes.
NOTE 2: The basic data schedule for the smart

metering is shown in Table G.1 and Table G.2.

The meter and CTs shown in Figure G.8 shall be tested

and calibrated by DEWA prior to installation onsite.
The CTs shall be located on the busbars immediately

after the circuit breaker/isolator at which the complete

installation is to be metered.
Removable links of adequate length shall be provided in

the busbar of each phase to enable easy maintenance

and replacement of CTs.
Three CTs shall be provided for each metering.
The following CT transformation ratios shall be used:
a)  200/5;
b)  300/5;
c)  400/5;
d)  800/5;
e)  1,600/5;
f)  2,400/5.

Each CT shall have the following markings (illustrated

in Figure G.10):

1)  manufacturer’s name and/or trademark;
2)  rated primary current and secondary current;
3)  rated frequency and primary maximum voltage;
4)  accuracy class;
5)  rated output (VA);
6)

terminal (secondary winding) identification

(S1, S2); and

power flow direction (P1, P2).

Figure G.10

Typical CT nameplate

Dubai Building Code

Part G: Incoming utilities

G 25

Table G.1

Electricity meter specifications

Table G.2

Current transformers (CT) specifications

No.

Description

Specification

Type of meters

Static type
kWh meter

Reference voltages and frequency

See G.4.2

Accuracy class

Meter application

System rating

3.1

Direct metering on LV system

≤120 A

Class 1

3.2

CT metering on LV system

>125 A

0.5s

Register

4.1

Type of register

LCD

4.2

Number of digits

8 (minimum)

4.3

Height of numerals

8 mm (minimum)

4.4

LCD screen size

80 mm × 20 mm or

approved by DEWA

Service conditions

5.1

Operating temperature range (minimum)

700 °C

5.2

Relative humidity

100%

5.3

Transport and storage temperature range (minimum)

850 °C

Type of communication

Modular type with detachable

communication module (to

choose wired or wireless

communication system)

Meter communication ports

Optical. M-bus, RS485, etc.

No.

Description

Specification

Rated secondary current

5 A

Maximum primary voltage

600 V

Rated frequency

50 Hz

Rated primary current
(only one is applicable)

200 A, 300 A, 400 A, 800 A,

1,600 A or 2,400 A

Rated burden

5 VA

Number of phases

Accuracy class
CT application

CT metering on LV system

Medium of installation

Air

Size of busbars (primary)

Rated primary current

a) 200 A, 300 A
b) 400 A
c) 600 A, 800 A

Busbar size

20 mm × 10 mm
30 mm × 10 mm
50 mm × 10 mm or
2 number 30 mm × 10 mm

d) 1,200 A, 1,600 A
e) 2,400 A

2 number 60 mm × 10 mm
2 number 80 mm × 10 mm

Dubai Building Code

Part G: Incoming utilities

G 26

Table G.3 Ambient design conditions for Dubai

G.4.6

Ambient design conditions

All equipment, apparatus, materials and accessories

used in electrical installations shall be suitable for

the purpose intended and capable of operating with

satisfactory performance in the climatic conditions

described in Table G.3.

Parameter

Condition

Altitude

Sea level (coastal)

Maximum outdoor ambient temperature

(shade):

48 °C

Minimum ambient air temperature

2.8 °C

Maximum ambient air temperature

48 °C

Maximum average temperature

over 24 h

37.8 °C

Maximum average over temperature

one year

26.9 °C

Relative humidity

100% (max.)

Thunderstorms per year

Occasional

Earthquake loading

0.07 g

Wind speed

45 m/s at 10 m height

Ground temperature

40 °C

Soil thermal resistivity

2.0 °C/m/w at depth

of 0.9 m

NOTE: Heavy condensation and sandstorms also prevail

G.4.7

Cables and conductors

G.4.7.1

General

For general purposes and in normal situations,

LSF/XLPE insulated, stranded copper conductor cables

shall be used for all fixed wiring installations. The

cables shall be appropriate to the building type and

conform to the respective standard from the

following list:
a)  BS 5467;
b)  BS 6004;
c)  BS 6724;
d)  BS 7211;
e)  BS 7629-1;
f)  BS 7846;
g)  BS 7889;
h)  BS 8436.
In certain circumstances, PVC insulated cabling may

be used for general purpose installations, subject to

approval by DEWA.

In flammable/explosive situations, cables shall be

selected in accordance with the requirements of NFPA

70, as required by Ch. 10 of UAE FLSC

[Ref. G.1]

Flexible cables and cords for use in electrical

installations shall be LSF insulated and sheathed,

stranded copper conductors conforming to BS 7211.

Cables for connection between ceiling rose and

luminaire for pendant type light fittings and for

enclosed luminaires shall be heat resistant silicone

rubber insulated with stranded copper conductor

conforming to BS EN 50525.

For elevators and similar applications, rubber insulated

or PVC insulated flexible cables conforming to BS EN

50214 shall be used.
kWh meter tails shall normally be single core PVC

insulated and sheathed cables conforming to BS 6004.
The cables used for control, relays, instrument

panels, etc. shall conform to BS 6231. Single core

cables armoured with steel wire or tape shall not be

used for AC circuits.

G.4.7.2

Minimum size of conductors

The size of conductor used for lighting circuits shall be

not less than 2.5 mm

The size of conductor used for utility sockets shall be

not less than 4 mm

Dubai Building Code

Part G: Incoming utilities

G 27

G.4.7.3

Current rating, size and voltage drop

All cables shall be sized to continuously carry the

normal current of the individual circuits based on

various laying conditions as applicable and the

maximum ambient temperature (see BS 7769).
The cable sizes for general purpose applications should

typically be not less than those given in Table G.4,

Table G.5 and Table G.6.

Table G.4

Typical recommended cable sizes – Single core LSF

insulated, non-armoured cables, stranded copper conductors

Size of cables in concealed

conduits

Max. rating of

MCB/MCCB

(A)

Max. load

current/

demand (A)

2 × 1C,

single-phase

(mm

)

3/4 × 1C,

three-phase

(mm

)

2.5

10/15

—

100

—

125

—

120

150/160

Table G.5

Typical recommended cable sizes – Multicore armoured LSF

insulated cables, copper conductors

Table G.6

Typical recommended cable sizes – Multicore armoured

XLPE insulated cables, copper conductors

Size of one 3/4 C LSF/SWA/

LSF cable installed in normal

situations (mm

)

Max. rating of

MCB/MCCB

(A)

Max. load

current/

demand (A)

2.5

10/15

100

125

160

120

180

150

200

185

250

240

300

350

400

Size of one cable installed in

normal situations (mm

)

Max. rating of

MCB/MCCB

(A)

Max. load

current/

demand (A)

100

125

160

200

120

225

150

250

185

300

240

350

300

400

NOTE: The following process can be used to determine

which cable size to select from Table G.4, Table G.5 and

Table G.6.
a) Assess initial demand with safe diversity and

anticipated demand in future, if any, as applicable

to individual circuits, for selection of cable size,

breakers rating, etc.

b) Assess individual fault levels and select

MCBs/MCCBs accordingly.

c) Refer to manufacturer’s catalogues and select

MCBs/MCCBs, cable sizes, etc. for specific

applications, considering inductive/capacitive loads,

laying conditions, voltage drop, correction

factors, etc.

The voltage drop from the point of supply to any point

in the wiring installation shall be not more than 4%

of the nominal voltage of the electric supply, unless

otherwise specified.

Dubai Building Code

Part G: Incoming utilities

G 28

G.4.7.4

Cable colour identification

The colour identification of insulated cable cores of

unarmoured, armoured and flexible cables and of

sleeve, band or disc of bare conductors shall be as

indicated in Table G.7 and Table G.8.

Table G.7

Non-flexible cables and bare conductor colour identifiers

Table G.8

Flexible cables and cores colour identifiers

Function

Colour identification

Earth continuity

conductor (ECC)

Green

and Yellow

Neutral conductor

in single-phase and

three-phase circuits

(N)

Black

Phase conductor in

single-phase circuits

Red

Red (R)

Yellow (Y)

Blue (B) as

applicable

Phase conductor in

three-phase circuits
R-phase

Red

Y-phase

Yellow

B-phase

Blue

Function

Colour identification

Live

Brown

Neutral

Blue

Earth

Green

and Yellow

G.4.8

Wiring installations exposed to high

temperatures

Any part of a wiring installation (such as the individual

circuit cables, final connections to equipment,

appliances and light fittings) shall be rated to maintain

its performance at the temperatures likely to be

encountered. Heat-resistant sleeves shall be provided

for individual cores and/or heat-resistant cables.

For end connections to luminaries with incandescent

and halogen lamps, and fixed heating appliances,

heat-resistant sleeves and cables shall be rated for a

minimum operating temperature of 85 °C.

G.4.9

Wiring installations in hazardous

areas

All light fittings, wiring accessories and other electrical

equipment in potentially hazardous atmospheres shall

be selected in accordance with BS EN 60079.

G.4.10 Load balancing

In all cases where a three-phase supply is provided

to premises, the various categories of connected load

(such as lighting, socket outlets, water heaters,

single-phase air conditioning units, equipment,

apparatus, etc.) shall be distributed and connected

on red, yellow and blue phases as evenly as possible,

to maintain load balance between the phases at all

distribution levels.

G.4.11 Wiring accessories

G.4.11.1

Conduits and fittings

High impact rigid PVC conduits and fittings shall

conform to all relevant parts of BS 4607, BS EN 60423

and BS EN 61386. They shall meet the following

requirements:
a) be suitable for use at a maximum ambient

temperature of 48 °C;

b) not soften or suffer structural degradation at a

temperature of 70 °C;

c) be non-hygroscopic;
d) be heat-resistant.
PVC conduits shall be provided with copper/brass

terminals.

Steel conduits and fittings shall conform to the

relevant specifications in BS EN 60423 and

BS EN 61386. They shall be hot-dip galvanized to

Class 4 protection, both inside and outside.

Flexible steel conduits and fittings shall conform to

BS EN 61386.
Conduit systems shall be designed and installed to

exclude moisture, dust and dirt. Small drainage holes

shall be provided at the lowest part of the system to

avoid the accumulation of condensation.

Dubai Building Code

Part G: Incoming utilities

G 29

G.4.11.2 Trunking

Where applicable, surface and underfloor (duct)

trunking and their fittings shall conform to

BS EN 50085. Trunking and fittings shall be

constructed of steel, hot-dip galvanized both inside

and outside, or non-combustible insulating material

with removable covers. Installation of the trunking

shall be carried out strictly in accordance with the

manufacturer’s guidelines.
The protective conductor shall run inside the trunking

and not in parallel.
Small insulated cables shall not be installed in

perforated trunking.
Additional supports shall be provided where trunking

changes direction.
Earth bonding shall be provided between sections/gaps

in all trunking runs and bolted connections.

G.4.11.3 Cable trays and supports

Cable trays, accessories and supports shall be either

hot-dip galvanized or PVC-coated steel. Cable trays

shall be either the perforated type or ladder type. They

shall have sufficient strength and rigidity to support

the cables installed, and be provided with upstands of

dimensions sufficient to carry cables on both sides.

Cable tray systems, cable ladder systems and their

fittings shall conform to BS EN 61537.

All fittings, bends, tees, elbows, couplers, etc. and

supports shall be of factory-made sections and of the

same quality as the trays. Cables shall be fastened

securely by purpose-made clips, cleats or saddles.
Earth bonding shall be provided between sections/gaps

in all cable tray runs and bolted connections.
Small insulated cables shall not be installed in

perforated cable trays.
Additional supports shall be provided where cable trays

change direction or cable drops out of the cable tray.
Installation shall be carried out in accordance with

G.4.17.

G.4.12 Low-voltage switchgear and control

gear assemblies

G.4.12.1 Main and sub main distribution boards

MDBs and SMDBs installed within the consumer

installations shall be factory-built assemblies and

conform to the relevant parts of BS EN 61439/

IEC 61439.

The assemblies shall be constructed of materials

capable of withstanding the following when

encountered in normal service:
a)  mechanical stress;
b)  electrical stress;
c)  thermal stress;
d)  the effects of humidity.
Apparatus forming part of the assembly shall have

clearances, creepage distances and isolating distances

conforming to BS EN 61439/IEC 61439. These

distances shall be maintained during normal and

relevant service conditions.
The phase busbar, neutral bar and earth bar shall be

copper. They shall be colour identified as indicated in

Table G.7 and Table G.8. The neutral bar shall be of the

same cross-section as the phase busbar.
The circuit breakers, busbars, etc. shall be designed

and rated to suit individual applications at the site

conditions. Table G.9 may be used to indicate the

preferred details and parameters of the equipment

and components in MDBs/SMDBs for an individual

application.

Dubai Building Code

Part G: Incoming utilities

G 30

Parameter

Specification

I. Reference standards

BS EN 61439/IEC 61439

II. Rating of incoming supply

200 A [ ]
300 A [ ]
400 A [ ]
800 A [ ]
1600 A [ ]
2,500 A [ ]

Breaker/isolator +
(+On-load)

Breaker [ ]
Isolator [ ]

III. Construction

1. Mounting

Wall [ ]
Floor [ ]
Pedestal [ ]
...................................[ ]

2. Degree of protection of the enclosure for

installation

Indoor-IP41/42 [ ]
Outdoor-IP54/55 [ ]
...................................[ ]

3. Painting/finish (internal/external)

Stove enamelled [ ]
Epoxy [ ]
Polyester [ ]
Galvanized [ ]
...................................[ ]

4. Front cover (+neoprene)

Hinged [ ]
Bolted [ ]
Panel lock [ ]
Gasketted+ [ ]

Table G.9

Specification of MDBs/SMDBs

Parameter

Specification

5. kWh meter reading provision

Glass window [ ]
Gasketted [ ]

6. Cable tray

Top [ ]
Bottom [ ]
Top and bottom [ ]

7. Ventilation

Natural via louvers [ ]
Mechanical exhaust/supply [ ]
...................................[ ]

8. Sealing/pad locking provision

IV. Internal layout/arrangement and fault rating

1. Segregation of live parts: Incoming supply

terminals/lugs

Barrier [ ]
Shroud [ ]
Firmly secured [ ]
Separately mounted and removable by tool [ ]

Busbar, tap-out connections and terminals
(separate and independent of each other)

Firmly secured [ ]
Separately mounted and removable by tool [ ]

Neutral and earth busbars and terminals

Separately mounted with adequate working

clearances/spacing from incoming supply

terminals/lugs [ ]

2. Arrangement of busbars and tap-out

connections to outgoing circuit breakers

Rigid, firmly secured, supported, direct and as

short as possible [ ]
Adequately sized [ ]
Min. number of bolted joints [ ]

3. Rating/size of phase and neural busbars and

terminals (at max. 50 °C ambient)

Rated for max. 70 °C internal ambient, consistent

with the rated incoming supply breaker/isolator

[ ]

Tinned electrolytic copper [ ]

Dubai Building Code

Part G: Incoming utilities

G 31

Parameter

Specification

4. Rating of main incomer and busbars DEWA’s

...................................[ ]

- Min. fault rating

40 kA [ ]
...................................[ ]

5. Min. and max. rating of outgoing circuit

breakers

...................................[ ]

- Min. fault rating

35 kA [ ]
...................................[ ]

6. Provision of min. working clearance/space for

incoming supply cable terminations

200 A
300 A
400 A

200 A/300 A/400 A incomers (mm)
800 A/1,600 A/2,500 A incomer (mm)
Outgoing circuit cables

250 [ ] 350 [ ] 450 [ ]
750 [ ]
With/without cable box [ ]
Adequate [ ]

7. Provision of supports/facility for dressing/

clamping outgoing circuit cables

Channels [ ]
Trunking [ ]
...................................[ ]
Max. height 2 m (From FFL) [ ]

8. Operational access/convenience for switchgear

incoming supply circuit breaker/isolator outgoing

circuit breaker

From outside of hinged door/bolted cover [ ]
Restricted/lockable [ ]

9. Maintenance access/replacement convenience

for switchgear components

Breaker [ ]
CTs [ ]
4 kWh meter [ ]
Gland plate [ ]

10. Provision for termination of Cu./XLPE/

AWA(S.C.)

Non-ferrous glands plate [ ]

Parameter

Specification

V. Identification

1. Rating of incoming supply and outgoing circuit

breakers:

(For the specified rating – refer approved single

line
diagram no.: ................................)

Thermal [ ]
Discrimination [ ]
Fault [ ]

2. Type of circuit breakers:
Incoming
Outgoing

ACB [ ] MCCB [ ] F/S [ ]
MCCB [ ] F/S [ ] C/L MCCB [ ]

3. Terminal ferrules for control/auxiliary circuits

kWh meter [ ] Indicating instruments[ ]

Other...................................[ ]

VI. Earthing

Compliance with G.4.19..................... [ ]

1. Rating/size of earth busbar and terminals

Adequate, consistent with the min. fault rating

specified under IV.4 and IV.5 [ ]

Adequate no. and size to terminate main and

circuits ECCs [ ]

2. Earthing of conductive parts

Enclosure [ ]
Hinged door [ ]
Cable glands [ ]

3. Termination of ECCs

Copper lugs [ ]

VII. Metering

Compliance with G.4.5................... [ ]

1. Standard indicating instruments

Volt meter with selector switch [ ]
Power factor (PF) meter [ ]
Ammeter [ ]
Current transformers [ ]
Indicating lamps [ ]

2. kWh meters/CTs

Tested and calibrated in DEWA [ ]

Table G.9 Specification of MDBs/SMDBs (continued)

Dubai Building Code

Part G: Incoming utilities

G 32

Parameter

Specification

3. Wiring/connections of CT meter

“Load” side of Incoming supply breaker [ ]

4. Protection of CT meter wiring (Allow six spare

fuse cartridges in the MDB)

Current coil [ ]
Voltage coil [ ]
“Sealed” type fuse [ ]
Heat resistant/High voltage grade [ ]

5. Mounting height from FFL

Max. 2 m. [ ]
Min. 0.8 m. [ ]

6. Mounting (if door/cover mounted)

Hinged door mounted [ ]

7. CTs for tariff metering

Exclusive [ ]
Accuracy class 0.2S [ ]
Matching ratio [ ]

VIII. Tests/Certification

1. Type test
2. Routine tests and checks:
Visual checks;
Screwed/bolted connections;
Operational checks;
Dielectric test.

As specified by the Consultants/Owner [ ]
Certificate for review/reference [ ]
Compliance with specifications [ ]
Tightness [ ]
Mechanical/Electrical [ ]
2,500/2,125 V (85%) [ ]

The following shall be provided in MDBs with a rating of 200 A or more, and may be

provided in SMDBs if appropriate:
a)

voltmeter (with R-Y-B “OFF” selector switch);

b) ammeter (with CTs as applicable);
c) maximum demand indicator/recorder;
d)

PF meter;

e) indicating lamps;
f) associated protective devices.
The switchgear, equipment and accessories shall conform to the following standards

as applicable:
1)  BS EN 60670;
2)  BS EN 60898-1;
3)  BS EN 60947;
4)  BS EN 61439;
5)  IEC 61439.

G.4.12.2 Final distribution boards

DBs installed for connection of the final circuits within electrical installations shall be

factory-built conforming to BS EN 61439/IEC 61439. An integral isolator shall be

provided for isolation of the incoming supply.

The circuit breaker accessories shall conform to the standards as specified by the

project designer(s).
Rewireable type fuses shall not be used in any wiring installation. Table G.10 may

be used to indicate the preferred details and parameters of the equipment and

components in final DBs for an individual application.

Table G.9 Specification of MDBs/SMDBs (continued)

Dubai Building Code

Part G: Incoming utilities

G 33

Parameter

Specification

I. Reference standards

BS EN 61439, BS EN 60947, IEC 61439

II. Rating of incoming supply

40 A [ ]
60 A [ ]
100 A [ ]
125 A [ ]
.................... [ ]

(+On-load)

Breaker [ ]
Isolator [ ]

III. Construction

1. Mounting

Wall [ ]
Pedestal [ ]
Surface [ ]
Recessed [ ]

2. Degree of protection of the enclosure for

installation

Indoor-IP41/42 [ ]
Outdoor-IP54/55 [ ]
...................................[ ]

3. Painting/Finish (internal/external)

Stove enamelled [ ]
Epoxy [ ]
Polyester [ ]
Galvanized [ ]
...................................[ ]

4. Front cover (+neoprene)

Hinged [ ]
Bolted [ ]
Panel lock [ ]
Gasketted+ [ ]

Table G.10

Specification of DBs

Parameter

Specification

5. Cable tray/conduit entry

Top [ ]
Bottom [ ]
Top and bottom [ ]

6. Assembly

Factory assembled [ ]
...................................[ ]

IV. Internal layout/arrangement and fault training

1. Segregation of live parts:
Incoming supply terminals/lugs

Barrier [ ]
Shroud [ ]
Firmly secured [ ]
Separately mounted and removable by tool [ ]

Busbar, tap-out connections and terminals

(Separate and independent of each other)

Barrier [ ]
Firmly secured [ ]
Separately mounted and removable by tool [ ]

Neutral and earth busbars and terminals

Separately mounted with adequate working

clearances/spacing from incoming supply

terminals/lugs [ ] and outgoing terminals of

MCBs/FS [ ]

2. Arrangement of busbars and tap-out

connections to outgoing circuit breakers/neutral

busbars

Segregated for each:

Group of MCBs/TP ways [ ]
ELCB Section [ ]
Rigid, firmly secured, supported, direct and as

short as possible [ ]
Adequately sized [ ]
Min. number of bolted joints [ ]
Min. number of looped connections [ ]

Dubai Building Code

Part G: Incoming utilities

G 34

Parameter

Specification

3. Rating/size of phase and neural busbars and

terminals (at max. 50 °C ambient)

Rated for max. 70 °C internal ambient, consistent

with the rated incoming supply breaker/isolator

[ ]
Tinned electrolytic copper [ ]
...................................[ ]

4. Min. fault rating of circuit breakers

6 kA (as per designed downstream short-circuit

current) [ ]

5. Provision of supports/facility for dressing

clamping outgoing circuit cables

Channels [ ]
Trunking [ ]
..................... [ ]

6. Operational access/convenience for switchgear.
Incoming supply circuit breaker/isolator
Outgoing circuit breakers

Max. height 1.8 m (from FFL) [ ]
From outside of hinged door/bolted cover [ ]
Restricted/lockable [ ]

7. Maintenance access/replacement convenience

for switchgear components

Breaker(s) [ ]
Isolators [ ]
ELCB/s [ ]
UV relays [ ]

8. Provision for termination of PVC/SWA/PVC/

XLPE/SWA/PVC cables

Gland plate [ ]
Cable gland [ ]

9. ELCBs/RCCBs

Window air conditioning [ ]
Split air conditioning [ ]
Lighting [ ]
Small power [ ]
Others..................... [ ]

10. UV Relays with auto-reset timer

Window air conditioning [ ]
Split air conditioning [ ]
Others.................... [ ]

Parameter

Specification

V. Identification

1. Rating of incoming supply and outgoing circuit

breakers:

(For details of the rating specified – refer to

approved SLD/distribution schedules)

Thermal [ ]
Fault [ ]
Discrimination [ ]

Type of circuit breakers: Incoming Outgoing C/L-

Current Limit

Isolator [ ]
MCCB [ ]
C/L MCCB [ ]
C/L MCCB [ ]
F/S [ ]
C/L [ ]
For general loads, Type 1/L[ ]
For motor load, Type 2/G [ ]

2. Colour codes for internal, main circuits wiring:
Phase
Neutral
Earth

Red/yellow/blue [ ]
Black [ ]
Green and yellow [ ]

3. Terminal ferrules for control/auxiliary circuits

Indicating instruments [ ]
Others..................... [ ]

4. Permanent labels, engraved, “Traffolite” or

similar

Board designation [ ]
Controls [ ]
Circuit designation [ ]
Indications [ ]
Warning notice(s) [ ]
ELCB/UV relay section [ ]

Table G.10 Specification of DBs (continued)

Dubai Building Code

Part G: Incoming utilities

G 35

Parameter

Specification

VI. Earthing

Compliance with G.4.19..................... [ ]

1. Rating/size of earth busbar and terminals

Adequate, consistent with the min. fault rating

specified under IV.4 [ ]

Adequate no. and size to terminate main and

circuits ECCs [ ]

2. Earthing of conductive parts:

Enclosure [ ]
Hinged door [ ]
Cable glands [ ]

3. Termination of ECCs

Copper lugs [ ]

VII. Tests/certification

1. Type test
2. Routine tests and checks:
Visual checks
Screwed/bolted connections;
Operational checks
Dielectric test

As specified by the Consultants/Owner [ ]
Certificate for review/reference [ ]
Compliance with specifications [ ]
Tightness [ ]
Mechanical/electrical [ ]
2,500/2,125 V (85%) [ ]

Table G.10 Specification of DBs (continued)

G.4.13 Apparatus and accessories

G.4.13.1 Switches

Switches provided for local isolation of electric supply to individual apparatus and/or

circuits shall conform to BS EN 60669. The rating of the switches shall be selected

based on individual applications, such as for resistive or inductive loads. The current

rating shall be not less than 5 A.
Switches shall be metal clad when used within industrial installations.
Switches installed for control of discharge lighting shall have a minimum current

rating that is twice the steady state continuous current of the circuits.

For large groups of lighting, a gang switch shall be provided with phase barrier inside

the switch boxes.

For outdoor locations, switches with weather protection classified as IP55 in

accordance with BS EN 60529 shall be used.

For areas with a high risk of fire or explosion, gas sealed switches conforming to

BS EN 60079 shall be used.

For appliances rated 20 A and above, and where visual indication of the presence of

power is desired, a DP switch with neon indicator shall be provided.

Dubai Building Code

Part G: Incoming utilities

G 36

Figure G.11 Typical 3-pin flat, double-pole, shuttered, switched single

socket

Shaver socket outlets shall conform to:
a) BS EN 61558 in bathrooms; and
b) BS 4573 in rooms other than bathrooms.
In hotel rooms, 5 A plugs and socket outlets for table

lamps which are switched from a dedicated lighting

circuit shall conform to BS 546.
Industrial plugs and socket outlets shall conform to

BS EN 60309. They shall feature a switch that is

integrally built in or attached to them. The rating and

type of socket outlets with plugs shall be selected

to suit individual applications and shall not be

interchangeable for different current ratings.

Weather protected type (classified as IP55 in

accordance with BS EN 60529) socket outlets shall be

used for outdoor applications.

G.4.13.3

Arc fault detection devices (AFDDs)

Additional protection to mitigate the risk of fire due to

arcing is recommended in certain applications. AFDDs

protect against series and parallel arcing by detecting

low-level hazardous arcing that circuit breakers, fuses

and RCDs are not designed to detect.

AFDDs shall be selected in accordance with

BS EN 62606. An AFDD shall be placed at the origin of

the circuit to be protected.

AFDDs are available in the following types:

one single device, comprising an AFD unit and

opening means, intended to be connected in series

with a suitable short-circuit protective device

declared by the manufacturer as conforming to one

or more of the following standards:
1)  BS EN 60898-1;
2)  BS EN 61009-1; or
3)  BS EN 60269 series;

one single device, comprising an AFD unit

integrated in a protective device conforming to one

or more of the following standards:
1)  BS EN 60898-1;
2)  BS EN 61008-1;
3)  BS EN 61009-1; or
4)  BS EN 62423;

an AFD unit (add-on module) and a declared

protective device, intended to be assembled onsite.

Examples of where such devices can be used include:
1) premises with sleeping accommodation;
2)

locations with a risk of fire due to the nature of

processed or stored materials;

3) locations with combustible construction materials;
4)

structures having fire propagating features; and

5) locations with endangered or irreplaceable objects

(such as museums, libraries, art galleries).

G.4.13.2 Plugs and socket outlets

Single-phase plugs and socket outlets used in domestic

and commercial installations shall conform to BS 1363.

The socket outlets shall be of the type illustrated in

Figure G.11.

15 A plugs and socket outlets used in domestic and

commercial installations shall conform to BS 546.

Dubai Building Code

Part G: Incoming utilities

G 37

G.4.13.4

Surge protection devices (SPDs)

Surge protection devices shall be implemented on electrical distribution systems

within new buildings. SPDs shall have the necessary capability to deal with the

current levels and durations involved at the point of installation.

For the protection of AC power circuits, SPDs are allocated a type number. The

number corresponds to a test class from the BS EN 61643 series as follows, and as

illustrated in Figure G.12:

type 1 – only used where there is a risk of direct lightning current and typically

used at the origin of an installation;

type 2 – used at DBs;

type 3 – used at or near equipment.

Figure G.12

SPD installation location based on type

Figure G.13

Cooker control unit installed within 2 m of appliance

4.4 in Institution of Engineering and Technology, 2018. Electrician's

guide to the building regulations

[Ref. G.2]

)

Key

01: Type 1 Main switchboard

02: Type 2 Sub distribution

03: Type 3 Final equipment

Key

01: Control switch to be located

within 2 m from controlled appliance

02: Electric hob

03: Electric oven

04: Consumer unit

G.4.13.5 Cooker control units

All stationary cooking appliances in domestic premises shall have a cooker control

switch. The switch shall conform to BS 4177 and be located separately from the

appliance (see Figure G.13). The cooking appliance shall incorporate an integral

earthing terminal.
The cooker control switch shall be two-pole (for a single-phase appliance) or four-

pole (for a three-phase appliance). It shall be connected to a separate final sub-circuit

from the DB, through a 100 mA ELCB.

Dubai Building Code

Part G: Incoming utilities

G 39

G.4.13.7 Control of water heaters, saunas,

Jacuzzis and washing machines

Double-pole switches with neon indicator shall

be provided, appropriately rated for control of the

equipment. The final connection to the equipment shall

be made from a flex outlet plate. The plate shall be

mounted adjacent to the equipment.

For water heaters installed in a bathroom or water

closet, the control switch shall be installed immediately

outside the room. For saunas and Jacuzzis, the control

gear shall be placed outside the sauna room/cabin.
Water heaters, saunas, Jacuzzis and washing machines

shall be connected to a separate final sub-circuit from

the DB.
Water heaters shall incorporate an integral earthing

terminal adjacent to the phase and neutral terminals.

All terminals shall be housed in a suitable recess with a

splash proof removable cover. Every heater circuit shall

be protected by a 30 mA RCCB/ELCB.

G.4.13.8

Control of air conditioning unit/

equipment

Window-type room air conditioners with a maximum

cooling capacity of 1.5 kW shall be connected by a

15 A switched socket outlet. For other room

air-conditioning units, a double-pole switch of

appropriate rating, with flex outlet, shall be provided

and mounted adjacent to the unit.

Each room air-conditioning unit shall be connected to a

separate final sub-circuit from the DB.

A maximum of two window-type air-conditioning units

are permitted to connect on a single-phase supply.

Where three or more window-type units are installed,

they shall be balanced as evenly as possible over a

three-phase supply.
The breaker rating and wire size shall be selected based

on the connected load of the air conditioning unit,

subject to minimum 20 A with 4 mm

circuit wires.

G.4.13.9

Extra LV safety apparatus

Extra LV safety apparatus includes:

a) electric buzzers and bells;
b) mirror lights and shaver socket outlets in

bathrooms;

light fittings for underwater installations.

Extra-LV safety apparatus shall incorporate an

appropriately rated double wound safety isolation

transformer. The transformer shall either be integral

or mounted separately. A cartridge fuse or MCB shall

be incorporated in the secondary circuit. The safety

isolation transformer shall conform to BS EN 61558.

Segregation of LV and extra-LV circuits shall be in

accordance with G.4.18.4.

G.4.13.10 HV discharge lighting equipment

HV discharge lighting equipment and installations shall

conform to BS 559. They shall be rated for voltages

not exceeding 5 kV, RMS to earth, measured on open

circuit.

HV discharge lighting equipment, including neon signs,

shall not be installed without prior approval from

DEWA.

G.4.13.11 Electric motors and starters

Control of electric motors shall conform to

BS EN 60204 where the equipment is within the scope

of the standard.
All motors shall be protected against overload,

short-circuit and earth leakage. They shall also be

protected against voltage fluctuations and the loss of

one or more phases, as necessary for the individual

application.
Every motor having a rating exceeding 0.37 kW shall be

provided with control equipment incorporating means

of protection against overload of the motor.
Only the installation of single-phase motors rated up

to 3.7 kW, and three-phase motors up to 110 kW, is

permitted, unless otherwise approved by DEWA.

Dubai Building Code

Part G: Incoming utilities

G 40

Where multiple motors above 110 kW are proposed,

the advice of DEWA shall be sought on obtaining a bulk

supply.
Starters shall be provided with overload relays

of the thermal type. Relays shall have automatic

compensation for variations in ambient temperature

between 28 °C and 48 °C.
Starting equipment to limit current shall consist of any

of the following:
a)  adjustable speed drive;
b)  intelligent controllers;
c)  another type of device approved by DEWA.
All motors shall be provided with an isolator, to isolate

the motor from the supply during inspection and

maintenance. The isolator shall interrupt the supply on

all phases. The isolator may be integral with the control

gear or separate but shall be in close proximity to the

motor. The control gear shall incorporate emergency

stop pushbutton(s).
When motor starting gear is energized from an

auxiliary circuit, the auxiliary circuit shall also be

isolated during inspection and maintenance.
All starters, isolators and pushbuttons

(see Figure G.15) shall be clearly marked in Arabic and

English stating which machine they control and their

function. To avoid confusion, the words “START” and

“STOP” shall be used (and not “OPEN” and “CLOSED”).

Figure G.15

Push buttons

G.4.14 Standby generators

Standby safety power provision shall be made for all

projects and premises in the category of touristic,

commercial and cultural, that require dedicated

transformer and LV panel supplies. These include, but

are not limited to:
a)  shopping malls and shopping centres;
b)  hotel buildings;
c)  amusement and theme parks;
d)  museums;
e)  major exhibition halls;
f)  hospitals;
g)  main government buildings.

NOTE 1: For new and existing buildings, the following

are considered to be essential services/loads.
a)

separate main and/or sub-main LV panel;

in-house standby generator(s) of sufficient

capacity for 100% backup, with auto-changeover

functionality (ATS).

Motors and their control gear shall be located in well

ventilated areas with adequate space for operation,

inspection and maintenance.

Dubai Building Code

Part G: Incoming utilities

G 41

The following loads shall be served by standby

generators:
1) elevators, escalators, security systems, CCTV,

alarm systems, BMS systems, stairways,

entrances, control rooms, data centres, electrical

rooms, generator rooms, etc.;

minimum 20% of lighting installations in the

landlord areas (corridors, public lobbies, assembly

points, reception, underground parking, etc.).

NOTE 2: For new buildings, the following are

considered to be non-essential services/loads:

a) additional ACB(s) as incomer with auto-changeover

facility (motorized ACB operation) to connect to

external mobile generator for all non-essential LV

panels;

b) access for transportation and stationing of the

mobile generators, intake arrangements for

cabling and connections, identification labels and

notices for connection of the generator during

emergencies.

NOTE 3: The requirements listed above are for the

standby provision of electrical power under unforeseen

power interruptions only. Emergency and standby

power requirements of fire and life safety systems

are covered in Ch. 6 to Ch.10 of UAE FLSC

[Ref. G.1]

Emergency generators for operational continuity can

be shared with those required by UAE FLSC provided

that the shared generator(s) meets the requirements

of both codes.

Generator rooms shall be 2 h fire rated to conform

to Table 1.9, Ch. 1 of UAE FLSC

[Ref. G.1]

. Exterior

walls do not need to be fire rated unless there is a

risk of exterior fire spread and the wall is fire rated in

accordance with Ch. 1 of UAE FLSC

[Ref. G.1]

. Louvers

in fire rated walls are not permitted without opening

protection.

NOTE 4: Installing and connecting standby generators

in the consumer’s installation to maintain power supply

in the event of mains failure is permitted only with

prior approval from DEWA.
NOTE 5: The changeover circuit breaker or isolator

should have four poles for three-phase supply and two

poles for single-phase supply. This ensures that the

phases and neutral of the two systems remain separate

and distinct.
NOTE 6: The installation should be carried out in

such a way that there is no possibility of paralleling

generator supply with DEWA supply.
NOTE 7: Adequate mechanical and electrical interlock

should be provided between the incomer circuit

breakers or isolators of both the generator and DEWA

supplies. Full details of the equipment, including details

of the essential loads, and circuit and wiring diagrams,

should be submitted to DEWA for approval before

commencement of the works.

NOTE 8: Provision for connecting a mobile generator

with incomer rating 2,500 A/1,600 A, to maintain

power supply in the event of mains failure, should be

included in the MDB/LV panel. The circuit breaker

should be a four-pole type. Adequate mechanical and

electrical interlock should be provided between the

incomer circuit breakers of both the mobile generator

and DEWA supply.
NOTE 9: The location of main electrical room should

be near to the front entrance/approach road and

sleeves are to be provided for intake generator cables.

This provision is not mandatory for the main LV panel

connected with standby generator in auto/manual

changeover mode.

G.4.15

Power to fire pumps

Table 9.3, Ch. 9 of UAE FLSC

[Ref. G.1]

requires

a direct power supply from the utility company to

the main electric fire pump and jockey pump via a

dedicated DB located inside the pump room.

NOTE: It is the responsibility of the consumer to

provide this arrangement at the main LV panel.

Dubai Building Code

Part G: Incoming utilities

G 42

There are three possible options which are acceptable to both DCD and DEWA for

providing power supplies to main electric fire pump and jockey pump. These are

shown in Figure G.16, Figure G.17 and Figure G.18.

LV PANEL (FORM-4)

Figure G.16 Fire pump supply direct from DEWA transformer (substation within plot boundary)

Key

01: DEWA transformer

02: Stand by generator

03: DEWA supply cable

04: LV Panel (Form – 4)

05: Check meter

06: Fire pump ACB – 4P

07: Neutral bar

08: Electro – mechanical interlock - 4P

09: DEWA incomer ACB – 4P

10: Stand by generator incomer ACB – 4P

11: Earth bar

12: Minimum 6 m apart

13: Earth pits

14: Fire pump control panel

15: Fire pump

Dubai Building Code

Part G: Incoming utilities

G 43

Figure G.17 Fire pump supply from essential panel/MDB (substation within plot boundary)

Key

01: DEWA transformer

02: Mobile generator

03: DEWA supply cable

04: LV panel (Form – 4)

05: DEWA incomer ACB – 4P

06: Mobile generator incomer ACB – 4P

07: Electro – mechanical interlock – 4P

08: Neutral bar

09: Earth bar

10: Check meter

11: Minimum 6 m apart

12: Earth pits

13: Stand by generator

14: Fire pump control panel

15: Fire pump

LV PANEL (FORM-4)

Dubai Building Code

Part G: Incoming utilities

G 44

Metric cabinet

Figure G.18 Fire pump from essential panel/MDB (external DEWA feeder with

MCCB incomer and CT metering)

NOTE: For fire pumps requiring 300A or 400A direct feeder connections, the MDB

can be replaced with the respective fire pump panel.

Key

01: DEWA supply cable

02: Metering cabinet

03: Main incomer MCCB

04: kWh meter

05: Neutral bar

06: Earth bar

07: Minimum 6 m apart

08: Earth pits

09: Three-pole isolator

10: Electro-mechanical interlock – 4P

11: Fire pump control panel

12: Fire pump

G.4.16 Assessment of connected load and

maximum demand

G.4.16.1 Lighting and small power circuits

All lighting and fan circuits shall be installed as follows:
a) maximum load per circuit of 2,000 W;
b) minimum circuit wire/EEC size of 2.5 mm

LSF

copper, with maximum circuit breaker protection of

16 A.

If light fixtures are not selected at design stage, a

minimum of 100 W shall be used for each normal

lighting and fan point. Fluorescent lamps shall be

assessed as 1.8 times the lamp wattage.

Wherever fittings with discharge light, compact

fluorescent lamps or low-volt lamps are installed,

the circuit breaker rating, circuit conductor sizes and

number of fittings shall be selected based on the actual

load, including losses, for the specific application.

Prior approval from DEWA shall be obtained for every

installation.

A radial final sub-circuit shall be installed to serve

a maximum of five 13 A switched socket outlets in

rooms other than the kitchen. It shall be controlled by

a 20 A circuit breaker in the DB. A maximum of ten

socket outlets in rooms other than the kitchen shall be

connected to a ring circuit, controlled by a 30 A circuit

breaker.

Dubai Building Code

Part G: Incoming utilities

G 45

A current demand of 13 A shall be assumed for each

13 A switched socket outlet circuit. A minimum of 200

W per point shall be used for calculation purposes

for each 13 A switched socket outlet, installed for

general utility purpose, other than the kitchen. All twin

socket outlets shall be taken to be as two separate

socket outlet points. Kitchen area might need separate

circuits.
A current demand of 15 A shall be assumed for each

15 A switched socket outlet circuit. However, for

general purpose utility socket outlets, an assumed load

of 1,000 W per socket outlet installed in commercial

and industrial premises, and 500 W per socket outlet

in residential premises, is permitted.

For stationary appliances and equipment, including

air conditioners, the actual load of each appliance and

equipment shall be taken to be a connected load.

The current demand of specific equipment such as an

electric clock, and other current-using equipment with

a maximum rating of 5 VA, may be omitted from the

assessment of load.

For multi-consumer installations, including commercial

premises such as shops, showrooms, garages and

workshops, where provision for connection of

additional load might be required, the assumed

connected load of additional spaces/circuits shall

also be indicated in the load distribution schedules

submitted for DEWA’s approval (see G.4.16.2).

G.4.16.2

Maximum demand

All DBs shall be rated for the TCL before a demand

factor is applied.

The demand load of each final sub-circuit is

determined by adding the actual or assumed load of

individual points/appliance/equipment, whichever

is higher. An allowance for diversity shall be applied

where appropriate.
The details of load distribution schedules shall be

submitted for DEWA’s approval in the format identified

in Table G.11 to Table G.14.

The TCL of individual distribution levels/circuits shall

be in accordance with G.4.7 to G.4.16. An appropriate

demand factor worked out by a qualified electrical

Engineer is permitted, to determine the maximum

demand at the main or sub-main distribution level.

Demand factor is equal to or less than one.

Dubai Building Code

Part G: Incoming utilities

G 46

Table G.11 Typical details of connected load, maximum demand and kWh metering schedule

DETAILS OF CONNECTED LOAD, MAX. DEMAND & kWh METERING

PROJECT:

BUILDING/ ________

OWNER:

AREA:

PLANNED COMPLETION DATE:

CONSULTANT:

PLOT NO.:

LVP/MDB/SMDB ______ (OF) _______

LOCATION OF LVP/MDB:

CIRCUIT/

FEEDER

SMDB/DB

NO.

1-PH/

3-PH

ACB/

MCCB/

ISOLATOR

RATING

(A)

FAULT

DUTY

CABLE SIZE, TYPE

AND

NO. OF CORES

ECC

SIZE

1C,

LENGTH

CABLE

(m)

CONNECTED LOAD

(KW)

TOTAL

CONNECTED

/INSTALLED

LOAD

(TCL)

MAX.

DEMAND/

OPERATIONAL

LOAD

(MDL)

PROPOSED TYPE & NO.

OF kWh METERS

REMARKS

NO. OF

CORES

1C/2C/

TYPE

XLPE/

PVC/

SWA

SIZE

R-PH

Y-PH

B-PH

1-PH

(1)

3-PH

(2)

* LV/

(3)

Incomer:
Outgoing:

MDB CONNECTED TO: DEWA LV/DB TRANSFORMER

SMDB CONNECTED TO: MDB…..

TOTAL CONNECTED LOAD

PER PHASE:

TOTAL:

DEMAND FACTOR:

MAX. DEMAND: ______ kW

* OVERALL TOTAL CONNECTED/INSTALLED LOAD (TCL): __________kW

TOTAL BUILT-UP AREA:

CONSULTANT/CONTRACTOR:

TEL:

FAX:

* TCL - shall include all loads proposed to be installed including standby, spare and future load provisions..

Type of meter (rating of incomer): (1) Up to 60 A (2) Up to 125 A (3) LV CT … / … A /HV CT … / … A (* 200/5 Amps CT metering)

(1)Phase

(3)Phase

Dubai Building Code

Part G: Incoming utilities

G 47

Table G.12 Typical load distribution schedule

LOAD DISTRIBUTION SCHEDULE (1-Phase)

PROJECT:

BUILDING/ ______

LOCATION OF DB:

DB No.:
FED FROM:

MDB/SMDB ________/ METER ENCLOSURE

TING

INC

OME

TING

LCB

. No.

CIR

. No.

MCB R

TG. IN

AMP

CCT WIRE SIZE

C WIRE SIZE

ROOM/

AREA

CONNECTED LOADS/ POINTS

ATT

/UNIT

LOAD PER

CIRCUIT - WATT

MARK

LTG

FAN

. F

SH.

13 A S

H/D

COOKE

15 A S

' A

'S' A

. PUMP

TOTAL

CABLE SIZE: 1x 2/3/4C…

Cu. PVC/XLPE/SWA/PVC +1 X 1C,….

Cu. PVC, ECC

c. fan = ceiling fan, ex. fan = exhaust fan, sh. s/o = shaver socket - outlet

CABLE SIZE: 2 x 1C…

Cu. PVC +1 X 1C,….

Cu. PVC, ECC

w/h = water heater, h/d = Hair Dryer, 'w' = window type & 's' = split type

Dubai Building Code

Part G: Incoming utilities

G 48

Table G.13 Typical connected load/points schedule

TYPICAL CONNECTED LOAD/POINTS SCHEDULE

LOCATION OF DB:

LOAD:

SCHEDULE:

TING

INC

OME

TING

LCB

. No.

CIR

. No.

MCB R

TG IN AMP

CCT WIRE SIZE

C WIRE SIZE

ROOM/

AREA

CONNECTED LOADS/ POINTS

ATT

/UNIT

LOAD CIRCUIT

MARK

LTG

C_F

EX_F

_S/

13A S.

H/D

COOKE

15A S./

' A

'S' A

_PUMP

TOTAL

CABLE

+1X

Cu, G/Y PVC, ECC C_

Fan,

Socket

CABLE

X 1C,

Cu, G/Y PVC, ECC W/H

Split

Dubai Building Code (2021) - page 16