Electrical Installation Design Project_DUBAI STANDARD_ by Mohnad Ibrahim

Building Electrical Installation
Design and Drafting Project
Project using UAE (Dubai) Standard
3/28/2015
Electrical Engineer
Mohnad Ibrahim Abdalla Jobbara

Project : Building Electrical Installation Design & Drafting
Flat Design 1
Designed by : Mohnad Ibrahim
Supervisor : Amjed Osman Elsayed

Building Electrical Installation Design Project
Designed by: Mohnad Ibrahim Abdalla Jobbara
Project in Dubai standards (BS)
Dubai Design parameters
Voltage : 230/400
Frequency : 50Hz
Diversity factor “D.F” : 0.9
Power Factor (Cos Ф) : 0.8
Building Specification:
Number of floors : 6 Floors + Ground floor
Number of flats : 36 flats ( 6 flats per floor (3 large “3BHK”, and 3 small “2BHK”) )
All 2BHK flats are typical (same)
All 3BHK flats are typical (same)
Number of lifts : 2 Lifts
Generator to supply power for lift 1 (10 HP), lift 2 (10 HP), Water pump (50 HP), Fire-fighting water
pump (50HP), DB GF.
The building is supplied with central chilled water system (MCC)
a. Chiller -1 100 kW
b. Chiller -2 100 kW
c. AHU -1 50 HP
d. AHU -2 50 HP
e. CHWPP-1(Duty) 20 HP
f. CHWPP-2(DUTY) 20 HP
g. CHWPP-3(Standby) 20 HP
h. CHWSP-1(Duty) 15 HP
i. CHWSP-2(Duty) 15 HP
j. CHWSP-3 (Standby) 15 HP

2 BHK Flat Design
Note :
W/H , W/M = 1500 w
FCU 1 Tonne = 1200 w
 See Drawings No: 7, 8, 9, 10, 11, 12
- Civil layout drawing
- Furniture layout drawing
- Lighting layout & Shop drawings
- Power layout & Shop drawings

Calculation:
Total connected load = (6900+7200+6600) = 20700 W
T.C.L = 20.7 kW
Diversity Factor (D.F) = 0.90 (90% used)
Max Demand = T.C.L x D.F
= 20.7 x 0.9 = 18.63 kW
Calculation of main isolator and main feeder cable of DB-F11
Max demand of DB-F11 = 18.63 kW // 3 Ф
Current (I) = P /( √3 x cos Ф xV
= 18.63 / (1.732 x 0.8x 400)
= 33.61 A
Plus 25% as safety factor
= 33.61 x 1.25 = 42.0125 A
Standard main isolator size = 50 A, 4P
Main feeder cable = 1 x 4C x 10mm², XLPE/SWA/PVC, Cu+ 1 x 1C x 10mm², PVC/PVC, Y/G Earth Cable

3 BHK Design
Note :
W/H , W/M = 1500 w
FCU 1 Tonne = 1200 w
 See Drawings No: 13, 14, 15 ,16 ,17,18

Calculation:
Total connected load = (9000 + 9100 + 8900) = 27000 W
T.C.L = 27 kW
Diversity Factor (D.F)= 0.90 (90% used)
= 27x 0.9 = 24.30 kW
Calculation of main isolator and main feeder cable of DB-F14
Max demand of DB-F11 = 24.3 kW // 3 ø
Current (I) = P /( √3 x cos Ф xV
= 24300/ (1.732 x 0.8x 400)
= 43.84 A
Plus 25% as safety factor
= 43.84 x 1.25 = 54.8 A
Main feeder cable = 1 x 4C x 16mm², XLPE/SWA/PVC, Cu+ 1 x 1C x 16mm², PVC/PVC, Y/G Earth
cable

DB – GF Design
Total Connected load = 5900 W ,
T.C.L = 5.90kW
Diversity Factor = 0.90 (%90 used)
Max demand = T.C.L X D.F
= 5.9 X 0.90 = 5.31 kW
Calculation of main isolator and main feeder cable of DB-GF
Max demand of DB-GF = 5.31kW // 3ø
Current (I) = P /( √3 x cos Ф xV)
= 5.31 /(1.732 x 0.8x 400)
= 9.58 A
Plus 25 % as safety factor
= 1.25 X 9.58 = 11.975 A
Main feeder cable = 1 x 4C x 4mm², XLPE/SWA/PVC, Cu+ 1 x 1C x 4mm², PVC/PVC, Y/G Earth cable
 See Drawings No: 1, 2, 3, 4, 5,6

SMDB – 1F load schedule
S.
NO
Load Design CB Wire Earth T.C.L
(kW)
R (kW) Y (kW) B (kW)
1 DB-F11
(2BHK)
50A, 4p 1 x 4C x
10mm²
1 x 1C x
10mm²
20.7 6.9 7.2 6.6
2 DB-F12
(2BHK)
50A, 4p 1 x 4C x
10mm²
1 x 1C x
10mm²
20.7 6.9 7.2 6.6
3 DB-F13
(2BHK)
50A, 4p 1 x 4C x
10mm²
1 x 1C x
10mm²
20.7 6.9 7.2 6.6
4 DB-F14
(3BHK)
60A, 4p 1 x 4C x
16mm²
1 x 1C x
16mm²
27 9 9.1 8.9
5 DB-F15
(3BHK)
60A, 4p 1 x 4C x
16mm²
1 x 1C x
16mm²
27 9 9.1 8.9
6 DB-F16
(3BHK)
60A, 4p 1 x 4C x
16mm²
1 x 1C x
16mm²
27 9 9.1 8.9
TOTAL LOAD 143.1 47.7 48.9 46.5
Total connected Load = 47.7 + 48.9 + 46.5 = 143.1 kW
Max demand = T.C.L X D.F
= 143.1 X 0.9 = 128.79 kW
Max demand of SMDB-F1 = 128.79 kW // 3ø
Current (I) = P /( √3 x cos Ф xV)
= 128.79/ (1.732 x 0.8 x 400)
= 232.37 A
Plus 25 % as safety factor
= 1.25 x 232.37 = 290.46 A
Main feeder cable = 1 x 4C x 185mm², XLPE/SWA/PVC, Cu+ 1 x 1C x 95mm², PVC/PVC, Y/G Earth cable
NOTE
 SMDB-2F to SMDB-6F are Typical to SMDB-1F

Central Chilled Water System (MCC)
1. Chiller (1)
P= 100kw 3phase
Current (I) = 100,000/(1.732×400×.8)= 180.42 A
Plus, 25% as safety factor 180.42× 1.25 = 225.525 A
Standard disconnect switch size = 250 A, 4P
Main feeder cable = 1 x4C×150mm²+ 1x1C×95mm² Y/G
2. Chiller (2)
P= 100kw 3phase
Current (I) = 100,000/ (1.732×400×.8)= 180.42 A
3. AHU -1 (50HP)
P= 50×746 = 37.3kW
Current (I) = 37300/ (1.732×400×.8) =67.3 A
Plus, 25% as safety factor 67.3 × 1.25 = 84.125 A
4. AHU -2 (50HP)
P= 50×746 = 37.3kW
Current (I) = 37300/ (1.732×400×.8) =67.3 A
Plus, 25% as safety factor 67.3 × 1.25 = 84.125 A
5. CHWPP-1 (20HP) (Duty)
P= 20×746 =14.92 kW
Current (I) = 14920/ (1.732×400×.8) =26.92 A

6. CHWPP-2 (20HP) (Duty)
P= 20×746 =14.92 kW
Current (I) = 14920/ (1.732×400×.8) =26.92 A
7. CHWPP-3 (20HP) (Standby)
P= 20×746 =14.92 kW
Current (I) = 14920/ (1.732×400×.8) =26.92 A
8. CHWSP-1 (15HP) (Duty)
P= 15×746= 11.19 kW
Current (I) = 11190/ (1.732×400×.8)= 20.19 A
Standard Main Isolator size = 30 A, 4P
9. CHWSP-2 (15HP) (Duty)
P= 15×746= 11.19 kW
Current (I) = 11190/(1.732×400×.8)= 20.19 A
10. CHWSP-3 (15HP) (Standby)
P= 15×746= 11.19 kW
Current (I) = 11190/ (1.732×400×.8)= 20.19 A

MCC Load Schedule
S/NO Load
Description
CB Wire earth T.C.L
(kW)
R (kW) Y(kW) B(kW) Type of
Motor
Starter
1 Chiller 1 250A,4P 1x4C×150mm² 1x1C×95mm² 100 33.33 33.33 33.33 -
2 Chiller 2 250A,4P 1x4C×150mm² 1x1C×95mm² 100 33.33 33.33 33.33 -
3 AHU 1 100A,4P 1 x4C×35mm² 1x1C×25mm² 37.3 12.43 12.43 12.43 VFD
4 AHU 2 100A,4P 1 x4C×35mm² 1x1C×25mm² 37.3 12.43 12.43 12.43 VFD
5 CHWPP-1
(Duty)
40A, 4P 1 x4C×10mm² 1x1C×10mm² 14.92 4.97 4.97 4.97 Y/▲
6 CHWPP-2
(Duty)
40A, 4P 1 x4C×10mm² 1x1C×10mm² 14.92 4.97 4.97 4.97 Y/▲
7 CHWPP-3
(Standby)
40A, 4P 1 x4C×10mm² 1x1C×10mm² 14.92 4.97 4.97 4.97 Y/▲
8 CHWSP-1
(Duty)
30A, 4P 1 x4C×6mm² 1 x1C×6mm² 11.19 3.73 3.73 3.73 Y/▲
9 CHWSP-2
(Duty)
30A, 4P 1 x4C×6mm² 1 x1C×6mm² 11.19 3.73 3.73 3.73 Y/▲
10 CHWSP-3
(Standby)
30A, 4P 1 x4C×6mm² 1 x1C×6mm² 11.19 3.73 3.73 3.73 Y/▲
TOTAL LOAD 326.76 108.92 108.92 108.92 -
* Standby loads are not consider in the calculation of Total load
Total Load Connected = 3 x 108.92 = 326.76 kW
Max demand = T.C.L x D.F
= 326.76 x 1 = 326.76 kW
Max Demand of MCC = 326.76 kW (3 phase)
Current (I) = P /( √3 x cosФ xV)
= (326760)/(1.732 x 400 x 0.8)
= 589.56 A
Plus, 25% as safety factor
= 1.25 x 589.56 = 736.95 A
Standard Main Isolator Size = 800 A, 4P
Main feeder cable for MCC = 2 x4C×300mm². XLPE/SWA/PVC, Cu+ 2x1C×150mm² Y/G

SMDB. Comm load calculation
I. Lift 1 (10 HP)
P= 10×746= 7.46 kW
Current (I) = 7460/(1.732×400×.8) = 13.46A
Plus, + 25% as safety factor 13.46× 1.25 = 16.825 A
II. Lift 2 (10 HP)
P= 10×746= 7.46 kW
Current (I) = 7460/(1.732×400×.8) = 13.46A
III. Water Pump (50 HP)
P= 50×746= 37.2 kW
Current (I) = 37200 / (1.732×400×.8) = 67.12 A
IV. Fire Fighting Water Pump (50 HP) – F.F.W Pump
P= 50×746= 37.2 kW
Current (I) = 37200 / (1.732×400×.8) = 67.12 A

SMDB. Comm load Schedule
S.NO Load
Description
CB Wire Earth Total
Load
R (kW) Y (kW) B (kW)
1 Lift -1 20A,4P 1 x 4C x 4mm² 1 x 1C x 4mm² 7.46 2.486 2.486 2.486
2 Lift -2 20A,4P 1 x 4C x 4mm² 1 x 1C x 4mm² 7.46 2.486 2.486 2.486
3 Water Pump 100A,4P 1 x4C×35mm² 1 x1C×25mm 37.2 12.4 12.4 12.4
4 F.F.W Pump 100A,4P 1 x4C×35mm² 1 x1C×25mm 37.2 12.4 12.4 12.4
5 DB - GF 15A,4P 1 x 4C x 4mm² 1 x 1C x 4mm² 5.9 2 2 1.9
TOTAL LOAD 31.772 31.772 31.672
Total Connected Load = 31.772 + 31.772 + 31.672 = 95.216 kW
= 95.216 x 0.9 = 85.6944 kW
Max demand of SMDB - Comm = 85.6944 kW (3 ø)
Current (I) = P / (√3 x cosФ xV)
= 85694.4 / (1.732 x 0.8 x 400)
= 154.61 A
Plus, +25% as safety factor
= 154.61 x 1.25
= 193.26 A
Main feeder cable for SMDB - Comm = 1 x4C×95mm². XLPE/SWA/PVC, Cu+ 1x1C×50mm² Y/G

MDB Load Schedule
S.No Load
Description
CB Wire Earth Total
Load
R
(kW)
Y
(kW)
B
(kW)
1 SMDB-
Comm
200A,4P 1 x4C×95mm² 1x1C×50mm² 95.216 31.772 31.772 31.672
2 SMDB-1F 300A,4P 1x4C
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
x185mm²
1 x1C x95mm² 143.1 47.7 48.9 46.5
8 MCC 800A,4P 2x4C×300mm² 2x1C×150mm² 326.76 108.92 108.92 108.92
9 Capacitor
bank
2000A,3P 4x4C×300mm² 4x1C×150mm²
TOTAL LOAD 426.892 434.092 419.692
*** The load on the phases is not balanced:
- Average power = (426.892 + 434.092 + 419.692) / 3 = 426.892 kW
- By subtracting 7.2 kW from Y phase and add it to B phase, then the phases will be balanced
Total Connected Load (T.C.L) = 426.892 + 434.092 + 419.692 = 1280.676 kW
Max demand = T.C.L x D.F
= 1280.676 x 0.9 = 1152.6084 kW
Max demand of MDB = 1152.6084 kW (3 ø)
Current (I) = P / (√3 x cosФ xV)
= 1152608.4 / (1.732 x 0.8 x 400)
= 2079.62 A
Plus, + 25% as Safety factor
= 2079.62 x 1.25 = 2599.525 A
Standard Main Isolator size = 3000 A, 4P, ACB
Main feeder Cable for MDB (Main Distribution Board) :
5x4C×300mm²XLPE/SWA/PVC+ 5x1C×150mm² Y/G

Transformer Sizing
1. Max demand of MDB = 1152.608 kW
2. Total max demand of MDB in kVA = Power (kW) / CosФ
= 1152.608 kW / 0.8
= 1440.76 kVA
3. Add 10 % as future load
Max demand in kVA = 1440.76 x 1.10 = 1584.836 kVA
4. Transformer Size = (Total max demand with future load in kVA/ Transformer load (90%))
= 1584.836 kVA / 0.90
= 1760.92kVA
Standard Transformer size = 2000kVA,
Voltage : 11kV/ (400-230V), Step-down, 3phase.
Frequency : 50 Hz,
Winding : Delta/Star,
Cooling : Air Cooled
Capacitor Bank Sizing
Size = Max demand MDB in kW x {tan (cos-¹ø1) - tan (cos-¹ø2)}
= 1152.608 kW x {tan (cos-¹0.8) - tan (cos-¹0.98)}
= 1152.608 kW x {tan (36.87) - tan (11.478)}
= 1152.608 kW x {0.75 -0.203}
= 630.47 kVAR
Standard size of Capacitor bank = 750 kVAR
Current (I) = P / (√3×sinø×V) = 630.47 kVAR / (1.732 x 0.6 x 400)
= 1516.71 A
Plus, +25% as safety factor = 1516.71 x 1.25
= 1895.88 A
Standard main Isolator size = 2000 A, 3P
Main feeder cable for MDB = 4x4C×300mm²+ 4x1C×150mm² Y/G
Generator Sizing
Max demand SMDB-Comm = 85.6944 kW
Max demand in kVA = Power (kW) / CosФ
= 85.6944 kW / 0.8 = 107.118 kVA
Generator Size = ( Total max demand in kVA / Generator load (80%) )
= (107.118 kVA / 0.8) = 133.8975 kVA
Standard Generator Size = 160 kVA, 3phase, 4 wire 230/400, 50 Hz

Cable tray layout and Panel Board location
Cable tray sizing
(1)→(1)
No of cables: 8 (MDB to SMDB-F (1-6) – MDB to MCC)
Cable size (MDB to SMDB-F (1-6)) = 1x4C×185mm² + 1x1C×95mm² Overall dia mm 56.4
Cable size (MDB to MCC) = 2x4C×300mm² + 2x1C×150mm² Overall dia mm 67.9
28.2+ 11×56.4 + 4×67.9+2 x 33.95 = 988.1
Standard cable tray size = 2 x (500mm×100mm), because the size exceeded standard cable tray size
(2)→(2) :
No of cables : 2 ( MDB to ATS – ATS to SMDB.Comm)
Cable size MDB to ATS = 1x4C×95mm² + 1x1C×50mm²
Cable size ATS to SMDB.Comm = 1x4C×95mm² + 1x1C×50mm²
Overall dia mm 42.0
(42× 3) + (21×2) = 168
Standard cable tray size = 200mm×200mm
(3)→(3) :
No of cables : 2 (SMDB.Comm to lift 1 and lift 2 )
Cable size lift 1 = 1x4C×4mm² + 1x1C×4mm²
Cable size lift 2 = 1x4C×4mm² + 1x1C×4mm²
Overall dia mm 16.9
Then (16.9× 3) + (8.45×2) = 67.6
(4)→(4)
No of cables : 2 (SMDB - Comm to Water pump and F.F Pump )
Cable size of water pump = 1x4C×35mm² + 1x1C×25mm²
Cable size of F.F.pump = 1x4C×35mm² + 1x1C×25mm²
Overall dia mm 32.2
Then, ( 32.2× 3) + (16.1×2)= 128.8
(5)→(5) :
No of cables : 3 (SMDB - Comm to water pump, F.F.pump ,and DB-GF )
Cable size of water pump = 1x4C×35mm² + 1x1C×25mm² Overall dia mm 32.2
Cable size of F.F.pump = 1x4C×35mm² + 1x1C×25mm Overall dia mm 32.2
Cable size of DB-GF = 1×4C×6mm² + 1x1C×6mm² Overall dia mm 19
Then, (16.1 x 2) + (32.2×3) + (19) + (9.5)= 157.3
(6)→ (6):
No of cables 1(DB-GF )
Cable size of DB-GF = 1×4C×4mm² + 1x1C×4mm²
Overall dia 4core DB-GF 16 = 16.9
Then, (2×8.45) + (16.9)= 33.8
Standard cable tray size = 50mm x 50mm

Cable Schedule
From To Size Length
MDB MCC 2x4C×300mm² 35 meters
MDB SMDB-Comm 1x4C×95mm² 10 meters
MDB SMDB-1F 1x4C x185mm² 15 meters
Voltage drop calculation
Note
The total voltage drop from MDB to DB or final mechanical equipment, must be less than 4% if
not, then we have to increase the cable size
 Calculation of the voltage drop from MDB to DB-F64
% Vd (MDB - DB-F64) = %Vd (MDB - SMDB-6F) + % Vd (SMDB – DB-F64)
1. % Vd (MDB to SMDB-6F)
Vd = I ×L (Meter) × VD / (R× 1000)
Cable size = 1x4C x185mm²
I = current of max demand of SMDB-6F = 232.37 A
L = 60 Meters, R = 1
VD = 0.26 (See page 34, cable data table)
Vd = (232.37 × 60× 0.26)/(1000×1) = 3.63 V
%Vd = (3.63/400) ×100 = % 0. 9075
2. %Vd (SMDB-6F to DB-F64)
Vd = I ×L (Meter) × VD / (R× 1000)
Cable size = 1 x 4C x 16mm²
I = current of max demand of DB-F64 = 43.84 A
L = 20 Meters
R = 1
Vd = (43.84 × 20× 2.5)/(1000×1) = 2.192 V
%Vd = (2.192/400) ×100 = % 0.548
Voltage drop:
% vd (MDB - DB-F64) = %Vd(MDB - SMDB-6F) + % Vd (SMDB-6F – DB-F64)|
= 0.9075% + 0.548 %
= 1.46 %, (voltage drop Less than 4%, so it is acceptable sizes)

 Calculation of the voltage drop from MDB to Chiller
% Vd (MDB- chiller1)= %Vd(MDB-MCC) + % Vd(MCC-Chiller1)
1. %Vd(MDB-MCC) :
Vd = I ×L (Meter) × VD / (R× 1000)
Cable size = 2x4C×300mm²
I = current of max demand of MCC = 589.56 A
L = 35 Meters
R = 2
Vd = (589.56 × 35× 0.185)/(1000×2) = 1.9087 V
%Vd = (1.9087/400) ×100 = % 0.48
2. % Vd(MCC-Chiller1):
Vd = I ×L (Meter) × VD / (R× 1000)
Cable size = 1x4C×150mm²
I = current of max demand of MCC = 180.42 A
L = 30 Meters
R = 1
Vd = (180.42 × 30× 0.30) / (1000×1) = 1.62378 V
%Vd = (1.62378/400) ×100 = % 0.406
Thus, % Vd (MDB- chiller1) = %Vd(MDB-MCC) + % Vd(MCC-Chiller1)
= 0.48 % + 0.406%
= 0.886 % (< 4 % “less than 4%)
So, the sizes of all cables are in acceptable range, the cables are OK

Short circuit calculation
Method to be used for calculation: Per- unit method
Z → Impedance
P.u→ per unit
Assume base MVA = 100MVA
Collect information from nearest substation about the fault level.
Fault level = 350 MVA
Steps:
(1) Zpu network = Base MVA/ Fault MVA
(2) Zpu T/F = (Z% × Base MVA)/(100×T/F MVA)
T/F = 2000 kVA = 2 MVA * T/F = Transformer
(3) Zpu cable:
Z cable = (Z/Km× L(Meters))/(R×1000)
Z/Km = page no .106
Zpu cable = (base MVA×Zcable)/ (KV)²
V=400 = 0.400 kV
(4) Total Zpu MDB = Zpu net + Zpu T/F + Zpu cable
(5) Fault MVA at MDB = Base MVA/Totale Zpu
(6) Short –circuit rating of MDB = Fault MVA/ (√3×kV) = kA

Calculation of the short circuit current for MDB, SMDB-1F, DB-F11
(1) Zpu network = Base MVA/ Fault MVA
= (100 MVA)/(350MVA)= 0.286Pu
(2) Zpu T/F = (Z% × Base MVA)/(100×T/F MVA)
T/F = 2000KVA = 2MVA
= (5×100MVA)/(100×2MVA)= 2.5Pu
(3) Zpu cable: (T/F to MDB) 4×4C×300mm²
Z/Km = 0.1212 , L (Meters) = 15 meters
= (0.1212 × 15)/(5×1000) = 0.0003636 Ω
Zpu cable(T/F to MDB) = (base MVA×Z cable)/ (KV)²
V=400 = 0.400 KV
= (100MVA×0.0003636)/(0.400)²
= 0.22725 Pu
(4) Total Zpu MDB = Zpu net + Zpu T/F + Zpu cable
= 0.286 + 2.5 + 0.22725 = 3.01325 pu
(5) Fault MVA at MDB = Base MVA/Total Zpu
= (100MVA)/(3.01325) = 33.187 MVA
Short –circuit rating of MDB = Fault MVA/ (√3×kV)
= (33.187 MVA)/(1.732×0.400 kV) = 47.9027 kA
Standard short-circuit rating at MDB = 50 KA
(1) Zpu cable : (MDB to SMDB-1F) : 1×4C×185mm²
Z/Km = 0.184 , L meters = 35meters
= (0.184 × 35) / (1×1000) = 0.00644Ω
Zpu cable (MDB to SMDB-1F) = (base MVA×Z cable)/ (kV) ²
V= 400 V = 0.400 kV
= (100MVA×0.00644)/(0.400)²
= 4.025 Pu
(2) Total SMDB-1F = Zpu MDB + Zpu cable (MDB TO SMDB-1F)
= 3.01325 + 4.025 = 7.03825 pu
(3) Fault MVA at SMDB-1F = Base MVA/Total Zpu
= (100MVA)/ (7.03825) = 14.208 MVA
Short –circuit rating of SMDB-1F = Fault MVA/ (√3×kV)
= (14.208 MVA)/(1.732×0.400 kV) = 20.51 kA
Standard short-circuit rating at SMDB-1F = 25 KA

(3) Zpu cable : (SMDB-1F to DB-F11) : 1×4C×10mm²
Z/Km = 2.336 From page no (106) in the manual
= (2.336 × 20)/(1×1000) = 0.04672Ω
Zpu cable (SMDB-1F to DB-F11) = (base MVA×Z cable)/ (kV)²
V= 0.400 = 0.400 kV
= (100MVA×0.04672)/(0.400)²
= 29.2 pu
Total Zpu(SMDB-1F toDB-F11
= Zpu SMDB-1F + Zpu cable (SMDB1Fto DB-F11)
= 7.03825 + 29.2 = 36.23825 pu
Fault MVA at DB-F11 = Base MVA/Total Zpu
= (100MVA) / (36.23825) = 2.76 MVA
Short –circuit rating of DB-F11 = Fault MVA/ (√3×kV)
= (2.76 MVA) / (1.732 × 0.400 kV) = 3.98 KA
Standard short-circuit rating at DB-F11 = 6 KA

Drawings:
Civil Layout Drawing No (1)
Lighting Layout Drawing No (2)

Lighting Shop Drawing No (3)
Power Layout drawing No (4)

Power Shop Drawing No (5)
Ground Floor Cable Tray Layout Drawing No (6)

Furniture Layout Drawing No (8)

Lighting Shop drawing No (10)

Power Layout Drawing No (11)

Furniture Layout Drawing No (14)

Lighting Shop Drawing No (16)
Power Layout Drawing No (17)

Electrical Installation Design Project_DUBAI STANDARD_ by Mohnad Ibrahim

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