Introduction section1: general requirements



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DEWA Regulations Book - UPDATED 2017

APPENDIX 4


DATA SCHEDULE FOR ELECTRICITY METERS AND CURRENT TRANSFORMERS
(Refer Section 3, for Regulations)



    1. Electricity Meters:




Sr. No.

Description




1.


Type of Meters

Static type







Kilo Watt-hour Meter

2.

Reference voltages & frequency

Refer clause 1.2,

3.

Accuracy Class

Section 1




Meter Application System Rating




3.1

Direct Metering on LV system < or = 120 A

1

3.2

CT Metering on LV system > 125 A

0.5S

4.

Register




4.1

Type of register

LCD

4.2

No. of digits

8 (minimum)

4.3

Height of numerals

8 mm (minimum)

4.4

LCD Screen Size

80 mm x 20 mm (or)







approved by DEWA

5.

Service Conditions




5.1

Operating temperature range (minimum)

700C

5.2

Relative Humidity

100%

5.3

Transport & Storage temperature range (minimum)

850C

6.

Type of meter communication

Modular type with detachable







communication module







(to choose wired or wireless







communication system)

7.

Meter communication ports

Optical, M-Bus, RS485, etc




    1. Current Transformers:




SR. No

Description




1.


Rated Secondary Current



5A


2.

Maximum primary voltage




600 V

3.

Rated Frequency




50 Hz

4.

Rated primary Current




160A,200A, 300A,




(only one is applicable)




400A, 600A,










800A,1200A, 1600A or










2400A

5.

Rated burden
















5 VA

6.

No. of Phases
















1

7.

Accuracy Class










CT Application

System Rating







CT metering on LV system

> 125A

0.2S

8.

Medium of installation




Air

9.

Size of Busbars (Primary)










Rated Primary Current




Busbar Size




a) 160A, 200A, 300A




20 mm x 10mm




b) 400A




30 mm x 10 mm




c) 600A, 800A




50 mm x 10 mm










or 2 Nos. x










30mm x 10mm




d) 1200A, 1600A




2 Nos. x 60mm x 10 mm




e) 2400A




2 Nos. x 80mm x 10mm

APPENDIX 5 SELECTION OF CABLES


Recommended size of cables for use in fixed wiring installation, for general purposes, and in normal situations, in the Emirate of Dubai.


TABLE - 1




Single - Core PVC insulated, non-armoured, Stranded copper Conductors (BS 6004 & BS 6346)


Size of cables, in 'concealed' conduits

Max. rating of MCB/MCCB
(Amps)

Max. Load current/demand
(Amps)

2 x 1C, 1 Phase (mm2)

3/4 x 1C, 3 Phase (mm2)

1.5


1.5


10


10


2.5

2.5

15

15

4

4

20

20

6

6

25

25

6

10

30

30

10

16

40

40

16

25

50

50

25

25

60

60

35

50

80

80

-

70

100

100

-

95

125

125

-

120

150

150



Common notes for Tables 1,2 & 3



      1. 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.




      1. Assess individual fault levels and select MCBs/MCCBs accordingly.




      1. Refer manufacturer’s catalogues and select MCBs/MCCBs, cable sizes, etc. for specific applications, considering inductive/capacitive loads, laying conditions, voltage drop, correction factors, etc.




      1. Refer Section 4 of Regulations.

TABLE - 2


Multi core armoured PVC insulated, copper Conductors ( BS 6346)


Size of 1 No., 3/4 C PVC/SWA/PVC Cable installed in normal situations (mm2)

Max. rating of MCB/MCCB
(Amps)

Max. Load current/demand (Amps)

1.5

2.5

4


6

10


16

25


35

50


70

95


120

150

185

240

300

400


10


15

20


30

40


50

60


80

100

125

160

180

200

250

300

350

400


10


15

20


30

40


50

60


80

100

125

160

180

200

250

300

350

400




Refer Table 1 for notes
TABLE - 3
Multi core armoured XLPE insulated, Copper Conductors (BS 5467)


Size of 1 No., Cable installed in normal situations
(mm2)

Max. rating of MCB/MCCB
(Amps)

Max. Load - current/demand (Amps)

10

16


25

35


50

70


95

120

150

185

240

300


50

60


80

100

125

160

200

225

250

300

350

400


50

60


80

100

125

160

200

225

250

300

350

400


Refer Table 1 for general notes
APPENDIX 6


COLOUR IDENTIFICATION OF UNARMOURED, ARMOURED AND FLEXIBLE CABLE CORES AND BARE CONDUCTORS
(Section 4 of regulations)


  1. Non - flexible cables and bare conductors:







Function



Colour Identification

Earth Continuity Conductor (ECC)


Neutral Conductor in 1 and 3-phase circuits (N)

Phase conductor in 1-phase circuits




Phase conductor in 3-phase circuits R - phase
Y - phase B - phase

Green - and - Yellow Black

Red or
Red (R) / Yellow (Y) / Blue (B) as applicable


Red Yellow Blue


  1. Flexible Cables and Cores:






Function



Colour of Core

Live Neutral Earth

Brown Blue


Green - and - Yellow

APPENDIX 7


SPECIFICATIONS OF MDBs/SMDBs
(Refer section 4) MDB/SMDB No. :

  1. REFERENCE STANDARDS


  1. RATING OF INCOMING SUPPLY BREAKER/ISOLATOR+

(+On-load)



  1. CONSTRUCTION




  1. Mounting


  1. Degree of protection of the enclosure for installation


  1. Painting/Finish (Internal/External)




  1. Front Cover (+Neoprene)


  1. KWH Meter reading provision 6.Cable Tray

  1. Ventilation




  1. Sealing/pad locking provision




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