Electricity.pdf

Course in 

BUILDING ELECTRICAL SYSTEMS DESIGN & DRAFTING

Prepared By Eng : AMJED OSMAN ELSAYED MOHAMED

E‐mail: [email protected] 

INTRODUCTION  design of the electrical installation in building used to be simple and straight forward . Such installations

generally

included electrical service from an electricity board company , power distribution within the building for sockets (receptacles ), air conditioniong and other electrical loads , lighting and few specialty system such as fire alram and telephone .

Eng : Amjed Osman

Building Electrical Design

Generation , transmission and distributions of electrical energy

Eng : Amjed Osman

Building Electrical Design

Transmission of Electricity  From power station to consumer

Power Station

High Voltage  Distribution

Generation Primary  Transmission

Secondary  Transmission

11kV, 17kV,

330kV,

60kV,

11kV,

22kV, 23kV

500kV

132kV

33kV

Yard  transformer

Regional  Substation

Zone  Substation

Eng : Amjed Osman

240/415V

Distribution Substation

Building Electrical Design

Distribution of Power High Voltage and low voltage distribution system Consumer 1 and 2: 230V two wire Consumer 3 : 230/400V three wire

Bulk Supply Consumer

Consumer 4 : 230/400V four wire

1

2

3

4

Delta/Star  transformer

Line 1(A) Line 2(B)

Three phase, high  voltage distribution

Line 3(C) Neutral

Three Phase  Star System

Three phase four wire distribution  low voltage 230/400V

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Building Electrical Design 5

Types of phase:‐  There are 3 phase types: 1. Red phase or phase (A) 2. Yellow phase or phase (B) 3. Blue phase or phase (C)

 Phase system: There are 3 types of phase system : 1. One ø system or 1 phase system 2. Tow ø system or 2 phase system 3.Three ø system or 3 phase system

Eng : Amjed Osman

Building Electrical Design

Eng : Amjed Osman

Building Electrical Design

ELECTRICAL CODES AND STANDARDS: Electrical codes :‐ the principles used in electrical design and installation are know as electrical codes. 

Examples : UK‐ UAE‐ QATAR‐ OMAN‐ SUDAN:‐ UK, UAE, Qatar ,Oman, Sudan follow B.S (British standards) know IEC(International Electrotechnical Commission)

USA‐KSA:‐ USA,KSA follow NEC codes (National electrical codes) which is chapter no 70 in NFPA book (National fire protection association )

European countries: European countries follow IEC standards (international electrical technical commission ). Eng : Amjed Osman

Building Electrical Design

Voltages and codes around the world  U.K → U.K follow B.S codes (also know as IEE regulation ) Normal voltages

230/400V 50Hz.

 USA→ USA follow NEC (NFPA 70) Normal voltage

110/220 220/380

60Hz 60Hz

 KSA→ KSA follow NEC (NFPA 70) Before 2010 KSA was having 2 voltages 127/220 V 60Hz 220/380 V 60 Hz In 2010 the ministry of electricity decided that new project after 2010 will have only one voltage through out KSA 220/380 60Hz Eng : Amjed Osman

Building Electrical Design

Voltages and codes around the world  UAE → UAE follow B.S

Normal voltage

230/400v 50 Hz

 SUDAN → Sudan follow B.S

Normal voltage

240/415v 50 Hz

 Qatar → Qatar follow B.S

Normal voltage 240/415v

50Hz Eng : Amjed Osman

Building Electrical Design

SWITCH  used for on or off purpose of small equipment like light – ceiling fan

–exhaust fan - socket – water heaters – washing machine – cooking range- window and split A/C – small water pumps.etc

 Rating of switch : the maximum current which can flow through switch safety without any damages for switch is know as rating of switch

Eng : Amjed Osman

Building Electrical Design

Standard Rating of Switch  5A  10 A  15 A  20 A  25 A  30A or 32 A

Note  In Gulf we used 10 A switch for light only  In Gulf we used 20 A switch for W/H – W/M etc Eng : Amjed Osman

Building Electrical Design

Types of Switch  One way switch

 Two way switch

 Intermediate switch

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Building Electrical Design

One way switch

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Building Electrical Design

Two way switch

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Building Electrical Design

Intermediate switch

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back box In Gulf they are 2 standard back box size 1. 3×3 2. 6×3

Gang : represents no. of switch in back box 1 Gang

2 gang

3 gang

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Building Electrical Design

Gang four gang 4G

five gang 5G

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six gang 6G

Building Electrical Design

Sockets Types of S/O in BS (Sudan , Oman, Qatar, UAE )  3pin → 13A general s/o → 15A s/o for A/C → 45A flex outlet for W/H , W/M , C/R

 K.S.A : S/Os in NEC standard are know as receptacles Receptacles → 15A/20A , 220 V Receptacles →15A or 20A , 127 V

Eng : Amjed Osman

Building Electrical Design

Sockets  Other classification

1. Single S/O outlet : The back box has only one s/o inside .the back box size is used 3×3.

2.Double or twin S/O outlet : The back box has two s/o , the back box size is used 6×3

3.Shaver outlet : (110_ 220 v)

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Building Electrical Design

Radial circuit

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Ring circuit

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flex outlet

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CILEING ROSE

WIRES AND CABLES: Wire : conductor + insulation (small size)  Cables : conductor + insulation + sheath (large size )  Bare conductor : only conductor (no insulation). Ex, over

head lines in Sudan

Units of wires and cables  mm² → Sudan and B.S countries (UAE, K.SA,Qatar) OR  AWG →(American Wire Gnage )  mm² : it is cross sectional area of conductor without

insulation Eng : Amjed Osman

Building Electrical Design

AWG

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Building Electrical Design

Equivalent of mm² to AWG MM²

AWG

REMARK

1.0 mm²

18 AWG

AWG For KSA

1.5 mm²

16 AWG

AWG For KSA

2.5 mm²

14 AWG

AWG For KSA

4 mm²

12 AWG

AWG For KSA

6 mm²

10 AWG

AWG For KSA

10 mm²

8 AWG

AWG For KSA

16 mm²

6 AWG

AWG For KSA

25 mm²

4 AWG

AWG For KSA

35 mm²

2 AWG

AWG For KSA

50 mm²

1 1/0 AWG

AWG For KSA

70 mm²

2/0 AWG

AWG For KSA

95 mm²

3/0 AWG

AWG For KSA

120 mm²

4/0 AWG

AWG For KSA

150 mm²

250 kc MIL

AWG For KSA

185 mm²

350 kc MIL

AWG For KSA

240 mm²

400 kc MIL

AWG For KSA

300 mm²

500 kc MIL

AWG For KSA

Eng : Amjed Osman

Building Electrical Design

CORE OF CABLES Core (c) represents the numbers of conductors in the cable , there are two types of the cable based on the cores of cables

1. Single core cable (1c)

2. Multi core cable (a) 2 core cable (2c)

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Building Electrical Design

CORE OF CABLES (b) Three core cable (3c)

(c)Four core cable (4c)

(d)3 ½ core or 3.5 core

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Building Electrical Design

Run of cable:Run of cable represents the no .of single core or multi core  Always the earth is separate run and 1c only . no multi core for earth

wire  We prefer multi core cables above 6mm², avoid single cables above 6mm² 1.5 mm² → single core (1c) 2.5 mm² → single core (1c) 4 mm² → single core (1c) 6 mm² → single core (1c) 10 mm² → (2c ,3c , 4c, 3.5c) 16 mm² → (2c ,3c , 4c, 3.5c) 25 mm² → (2c ,3c , 4c, 3.5c) : : 300 mm² → (2c,3c , 4c, 3.5c) Eng : Amjed Osman

Building Electrical Design

Earth wire sizing Earth wire is dependent on phase size Wire or cable size for phase and N

Earth wire or cable size

1.0mm²

1.0 mm²

1.5 mm²

1.5 mm²

2.5 mm²

2.5 mm²

4 mm²

4 mm²

6 mm²

6 mm²

10 mm²

10 mm²

16 mm²

16 mm²

25 mm²

16 mm²

35 mm²

25 mm²

50 mm²

25 mm²

70 mm²

35 mm²

95 mm²

50 mm²

120 mm²

70 mm²

150 mm²

95 mm²

185 mm²

95 mm²

240 mm²

120 mm²

300 mm²

150 mm²

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Building Electrical Design

Conductor materials

1. Copper (cu)

2. Aluminum (al) 

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Building Electrical Design

Insulation materials 1. PVC :(Poly-Viny Chloride) PVC insulated wires are used for smaller loads like light , fans , s/o , w/m , w/h , c/r  They can with stand up to 60 C,

 2. LSOH : Low Smoke zero Holagen LSOH insulated wires are used for smaller loads like lights , fans , s/o , w/h , w/m . c/r . Eng : Amjed Osman

Building Electrical Design

Insulation materials  XLPE : cross linked polyethylene  XLPE insulated cables are used as main

feeder cable (service wire) for DB OR SMDB OR MCC OR T/F etc. and for heavy mechanical load like chiller – AHU – Boilers  XLPE cables can with stand up to 90º c

 FR : Fire Retardant or MICC (Mincal Insulated Cable Conductor ) FR cable are professed for emergency load like lights fire fighting pumps , emergency lights ,fire alarms cables Eng : Amjed Osman

Building Electrical Design

Types power cable : 1.Un armoured cable

2. Armoured cable SWA (Steel Wire Armour ) b) AWA (Aluminum Wire Armour) c) SSA (Steel Strip Armour ) a)

d) ASA (Aluminum Strip Armour)

Eng : Amjed Osman

Building Electrical Design

Voltage classification  H.V → High Voltage (above 1000 v)  M.V → Medium Voltage (250 to 1000v)  L.V → Low Voltage (30 to 250 v)  ELV → Extra Low Voltage (voltage less

than 30 ac or 54 v dc) Grade of cable  means the with stand voltage whether the cable is for LV or MV or HV. Eng : Amjed Osman

Building Electrical Design

Color codes of cable PHASE

In sudan or gulf New color code countries in europe

Phase (A) or (1)

Red

Brown

Phase (B) or (2)

Yellow

Black

Phase (C) or (3)

Blue

Grey

Neutral

Black

Blue

Earth

Green or Y/G

Y/G

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Building Electrical Design

Final representation of cables 1×4c×10mm² ,XLPE/SWA/PVC.Cu,0.6/1kv + 1×1c×10mm², pvc /pvc ,cu Y/G                

1 → run 4c→ core 10mm²→size XLPE → insulation SWA→ armour PVC→ sheath Cu → conductor material 0.6/1kv → M.V /L.V grade Earth 1 → run 1c→ core 10mm²→ size PVC → insulation PVC→ sheath Cu → conductor material Y/G → Earth Eng : Amjed Osman

Building Electrical Design

Electrical faults  Types of electrical faults Over load Short circuit Earth –fault or shock Over voltage Under voltage Eng : Amjed Osman

Building Electrical Design

1. Over load Over load mean current more than rated current of equipment  Ex : 10 A rated switch 2A→ safe 6A→ safe 10A→ safe 11A→ un safe (over load current)  When over load current passes then the s/w gets damage.

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Building Electrical Design

2. Short circuit  When any phase of neutral or any two phase meet

each other then infinite current flows through them. Usually thousands of current in 1 ms (KA of current in 1ms ), this increase the temperature is know as short- circuit condition

Eng : Amjed Osman

Building Electrical Design

3.Earth – fault or shock  When any phase meet earth wire or any conducting materials eg

(metals – human body – water – etc. ) some a mount of current passes in to ground through the earth wire or any conducting material  This current passing to earth from phase wire is know as earth – leakage current and the fault is know as earth – fault . Good conductor

Bad conductor

Silver (best)

wood

Cu and AL

Rubber

All metals expect few semi‐ conductor

Plastic – paper – glass

Human body

porcelain

Water

Air Eng : Amjed Osman

Building Electrical Design

Summary  P – N → Short circuit  P – P → Short circuit  P – E or human body → earth fault –

shock  N – E or human body → No effect  E – human body → No effect

Eng : Amjed Osman

Building Electrical Design

Productive devices The devices which protected from electrical faults are knows as protective devices Types of protective devices 1. Fuse → protective from over load only 2. Circuit breaker → protects from over load and s.c faults 3. RCB or ELCB or GFCI→ protects from earth faults or shock 4. RCBO or RCCB → protects from over load , s.c and earth faults 5. UVR (Under Voltage Relay)→ protects from under voltage Eng : Amjed Osman

Building Electrical Design

Circuit Breaker : The  CB is protective devices which can  be operated manually and automatically it trips in case of over load and  short‐ circuit condition 

5 A to 40 A MCB (Miniature circuit breaker )

50 A to 600 A MCCB (Modulate Case circuit breaker ) 800 A to 3500 A ACB (Air Circuit Breaker)

Eng : Amjed Osman

Building Electrical Design

Standard of C.B (A)

Type of C.B

5

MCB

10

MCB

15

MCB

20

MCB

25

MCB

30 or 32

MCB

40

MCB

50

MCCB

60 or 63

MCCB

80

MCCB

100

MCCB

125

MCCB

150

MCCB

200

MCCB

225

MCCB

250

MCCB

300

MCCB

400

MCCB

500

MCCB

600

MCCB

800

ACB

1000

ACB

1250

ACB

1500

ACB

2000

ACB

2500

ACB

3000

ACB

3500

ACB

Eng : Amjed Osman

Building Electrical Design

Standard short – circuit rating of C.B 1. 6KA 2. 10KA 3. 16KA 4. 25KA 5. 35KA 6. 50KA Eng : Amjed Osman

Building Electrical Design

TYPES OF C.B 1.MCB → Miniature Circuit Breaker 2.MCCB→ Modulate Case Circuit Breaker 3.ACB → Air Circuit Breaker

other breaker used in H.V (power plants and s/s ) 4.VCB → Vacuum C.B 5. OCB → Oil C.B 6. SF6 Eng : Amjed Osman

Building Electrical Design

Types of MCB  B curve MCB 

 C curve MCB

 D curve MCB

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Building Electrical Design

Types of MCB

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Building Electrical Design

Application of B,C,D curve MCB

1. B curve MCB is preferred for lighting circuit. 2. C curve MCB is preferred for small heavy like W/H – W/M – C/R 3.D curve MCB is preferred for machine like (backing machine ).

Eng : Amjed Osman

Building Electrical Design

MCCB(Modulate Case circuit breaker ) Rating 50 to 600A

Types of MCCB 1. Adjustable MCCB here we can set the tripping value normally

2. Fixed or un adjustable MCCB

Eng : Amjed Osman

Building Electrical Design

ACB : Air Circuit Breaker Rating 800 to 3500A 1.Motorized with drawable ACB : Here the start and stop push buttons are operated by a motor which is required to be energized and after it is off we can with draw the ACB to avoid are flash

2.Motorized non_ with draw able ACB Here the start and stop push buttons are operated by a motor which is required to be energized and after it is off/on we need to with raw ACB Eng : Amjed Osman

Building Electrical Design

RCD or ELCB or GFCI  B.S (Sudan and UAE,Qatar)

→RCD (Residual Current Devices )

→ELCB (Earth Leakage Circuit Breaker)

 NEC (KSA)

→ GFCI : Ground fault Circuit Breaker Eng : Amjed Osman

Building Electrical Design

Working principle of RCD  The RCD continuously monitors the current difference

between phase and neutral . if the leakage current is equal to sensitivity of RCD then the RCD is trip  Recommended sensitivity of RCD :  For lights use 100 mA RCD (0.1A)  For sockets use 30 mA RCD (0.03A)  For W/H- W/M- C/R use 30 mA (0.03A)  For A/C use 100mA RCD (0.1A)  For under water lighting use 10mA RCD (0.001A) Note: the RCD is provide with a test buttons to verity that RCD is working propyl

Eng : Amjed Osman

Building Electrical Design

Working principle of RCD  No .of poles : Since neutral is compulsory in RCD we have

1. Two poles RCD

2. Four poles RCD

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Building Electrical Design

RCCB or RCBO :  RCCB

Residual Current Circuit Breaker

 RCBO

Residual CB with over current protection (over load & S.C)  Note  RCCB or RCBO protects from all 3 faults (over load , S.C and earth

fault)Since this technology is now they are very less used

Eng : Amjed Osman

Building Electrical Design

RCCB or RCBO  Ex : (C 40A - 100ma

- 10KA)

C → type of RCBO 40 A→ rating of RCBO 100mA → sensitivity of MCBO 10KA→ short- circuit rating  Note  In UAE they have both CB and RCD for all lights and W/H. S/O , A/C  In Qatar RCD are minatory for S/O , W/H , W/M only not require for lights and A/C.  In KSA RCD are not used GFCI are minatory only for equipment inside bath room and kitchen. Eng : Amjed Osman

Building Electrical Design

Isolator or disconnect switch (D/S):  Isolator or D/S is not a protective devices is it doesn’t trip in case of

any fault it is only meant for on and off purpose  It can look similar to CB with handle side handle or rotary handle Note  In sudan and B.S countries the isolator is used as main breaker knows as (main isolator ) inside the DB or final DB  Always install D/S near to every heavy mechanical equipment such as chiller , AHU , Motor and pumps , lights for maintains and repair purpose

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Building Electrical Design

STANDARD ISOLATOR RATING 1. 20 A 2. 25 A 3. 30 A 4. 40 A 5. 50 A 6. 60 A 7. 80 A 8. 100 A 9. 125 A 10. 150 A 11. 220 A 12. 225 A 13. 250 A 14. 300 A 15. 350 A 16. 400 A 17. 500 A

18. 19. 20. 21. 22. 23. 24. 25 26

600 A 800 A 1000 A 1250 A 1500 A 2000 A 2500 A 3000 A 3500 A

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Building Electrical Design

DB (NEC)

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DB (B.S)

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DB (B.S)

SMDB

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STANDARD ISOLATOR RATING  NO .OF POLES FOR ISOLATOR DB:

2P

4P

 No.of poles D/S near the heavy mechanical equipment  SPN for single phase equipment

 TPN for three phase equipment Eng : Amjed Osman

Building Electrical Design

Wires and cables insulation methods  Majorly the wires of cables are said to be installed in two methods  Cable in air No

(2) Cable in ground

1

Methods for cable in Air Free in Air

2

conduit

3 4 5

Cable trunking Cable tray Cable ladder

Methods for cable in ground Directly buried or directly laid under ground cable Duct bank or electrical ducts Cable tranch

Eng : Amjed Osman

Building Electrical Design

Conduit: (electrical pipe)  Material of conduit  PVC

 Metallic

 GI/GS→ Galvanized Iron/

Galvanized Steel Eng : Amjed Osman

Building Electrical Design

Conduit: (electrical pipe)  Material of conduit :  EMT→ Electrical Metallic Tubes  RGS/RGI →Rigid Galvanized Steel/

Rigid Galvanized Iron  Note  PVC conduits are used as connected conduit inside the wall , slabs ,

and floor screed.  GI/GS or RGI/RGS are used as exposed conduits or the wall , or slab in India and B.S countries (Qatar , UAE ,Oman)  EMT conduits are used as exposed conduits on the wall or slab in KSA Eng : Amjed Osman

Building Electrical Design

Standard size of conduits  ½ ´´ → 16 mm  ¾´´ → 20 mm  1´´ → 25mm  1¼´´→ 32 mm  2´´ → 50 mm  3´´ → 75 mm  4´´ → 100 mm  Note  ½ ´´ conduits are not recommended  ¾´´ (20 mm) 0r 1´´ (25 mm) conduit can be use for wiring

lighting  1´´ (25 mm) or (32mm) conduit can be used for wiring of s/o , w/h , w/m , c/r , pumps and low current system like fire alarms wires , CCTV telephone and TV wires. Eng : Amjed Osman

Building Electrical Design

Conduits accessories  Coupler : coupler used to join 2conduts

 Bends : In gulf countries bends are made 

at site in the same coduit using PVC bending 

Eng : Amjed Osman

Building Electrical Design

circular JB is fixed near to every light point , ceiling and exhaust and smoke electors

 Types of JB circular JB  One way

two way through

two way angle

two way U

three way

four way

Eng : Amjed Osman

Building Electrical Design

Junction box  octagonal JB

 back bax : are used for s/o flex outlet etc

 adapter : use for fixing conduit to the back box

Eng : Amjed Osman

Building Electrical Design

Standard mounting heights of wiring accessories  All switches → 1250 mm AFFL (After Finish Floor

Level) Light , fan , w/h , w/m .  Sockets →450 mm AFFL  Tel/sockets →450 mm AFFL  Sockets in kitchen → 250 mm above kitchen plat form  s/o for w/h , w/m , A/C , near the equipment

Eng : Amjed Osman

Building Electrical Design

Standard mounting heights of wiring accessories

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Building Electrical Design

conduiting laying of conduit is knows as coduiting there are three stages for conduiting

Conduiting in slab

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Building Electrical Design

Conduiting in wall

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Conduiting in floor

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Building Electrical Design

Cable trunking  Cable trunking is used to carry branch of wires (many wires )

 Materials' : 1. PVC cable trunking 2. Metallic cable trunking

Eng : Amjed Osman

Building Electrical Design

Standard size of cable trunking 1.  50mm ×50mm (5cm×5cm) 2. 100mm ×100mm (10cm×10cm) 3. 150mm ×150mm (15cm×15cm) 4. 200mm ×200mm (20cm×20cm) 5. 250mm ×250mm (25cm×25cm) 6. 300mm ×300mm (30cm×30cm) 7. 400mm ×400mm (40cm×40cm) 8. 500mm ×500mm (50cm×50cm) Note: other combination are also available ex : 300mm×100mm Eng : Amjed Osman

Building Electrical Design

Installation methods of cable trunking  The cable trunking can be installed is three method as per

requirements  On the surface of the wall

 Hanging from slab

 Under floor trunking

Eng : Amjed Osman

Building Electrical Design

CABLE TRAY Cable tray is used to carry heavy cable

 Types of cable tray:

1. Perforated cable tray : is preferred for carraying power cables

2. Plain cable tray : can be used for low current system like TV , CCTV ,FF

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Building Electrical Design

Materials of cable tray 1. No PVC 2. Metallic (a) Galvanized cable tray

(b) Hot dip galvanized cable

Eng : Amjed Osman

Building Electrical Design

Standard cable tray size 50mm ×50mm (5cm×5cm) 150mm ×150mm (15cm×15cm) 200mm ×100mm (20cm×10cm) 250mm ×100mm (25cm×10cm) 300mm ×100mm (30cm×10cm) 400mm ×100mm (40cm×10cm) 500mm ×100mm (50cm×10cm) 600mm×100mm (60cm×10cm) 800mm×100mm (80cm×10cm) 900mm×100mm (90cm×10cm) Note: if more than 900mm cable tray is required then use two cable tray parally

1) 2) 3) 4) 5) 6) 7) 8) 9) 10)

Eng : Amjed Osman

Building Electrical Design

Cable tray installation  Cable tray can be installed in three methods : 1. On the surface of wall

2. Hanging from cable

3.Floor mounted (on the floor ) Eng : Amjed Osman

Building Electrical Design

Cable laying methods on cable tray  There are three methods of cable laying on cable tray  Flat formation – touching  Flat formation – spacing  Trefoil formation (only for single core cables )

Eng : Amjed Osman

Building Electrical Design

Cable ladder  Cable ladder are preferred only for vertical installation only in

electrical shaft or riser

 Cable installation in ground :

there are three methods of cable tray installation in ground 1.Directly buried or directly laid under ground 2.Duct bank or electrical duct 3.Cable trench Eng : Amjed Osman

Building Electrical Design

Cable installation in ground 1.Directly buried or directly laid under ground

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Building Electrical Design

2.Duct bank or electrical duct

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3.Cable trench

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Building Electrical Design

Coordination with mechanical system 1. HAVC (Heating Ventilation and Air Conditioning ) 2. Plumbing

water supply b) drainage 3. Fire fighting 4. Conveyors like ,lifts scalolar 5. Swimming pool. a)

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Building Electrical Design

Types of HVAC system 1.

Window A/C

2. Split A/C

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3.VRV or VRF system

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4. Package A/C

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5. Central A/C – VAV system

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6. Chilled water system

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Building Electrical Design

Plumbing system 1. Water supply

2. Drainage system

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Building Electrical Design

 Fire fighting system

 Duty and stand by pumps Eng : Amjed Osman

Building Electrical Design

Plumbing system Lift :  The installation works of lift etc is done by separate contractor know as lift contractor  The elect.engineer has to provide a D/S inside the lift room for supply to the lift system  Summing pool : are usually done by separate contractor knows as swimming pool contractor .  Sometimes the elec. Engineer has to supply electricity to under water lights which is done at voltage not greater than 30 v a.c the lights shall be provide with 10ma RCD. Eng : Amjed Osman

Building Electrical Design

Panel board  An enclosure with protection devices such as C.B and

RCD knows as panel board .  Ex : DB – SMDB – MCC – MDB (All are panel board)  Switch gear : a panel board including instruments is knows as switch gear.  Ex : MDB – MCC

Eng : Amjed Osman

Building Electrical Design

MCC (motor control center )  MCC is a panel board to which major mechanical motors

or loads are connected.  MCC has measuring indicating remote start indicates.  Ex : MCC panel has ammeter voltmeter frequency meter power factor meter , phase indicators motor run off trip indicating lamps auto , manual selector switch CB and motor starters with remote terminal blocks.

Eng : Amjed Osman

Building Electrical Design

Panel board  The panel board and switch gear (DB- SMDB – MDB –

MCC ) are manufactured in separate factories knows as switch gear manufacturing company and these panel boards are delivered at site for installation Well – know switch gear companys : 1. ABB 2. Schneider electric 3. Mitsubishi 4. Merlin gerin 5. Siemens 6. L&T Eng : Amjed Osman

Building Electrical Design

Bus duct system  Note : bus duct has a housing with bus bar insulated , bus bar is used

to carry current of very high ratings , ex : above 600A only

 STANDARD BUS DUCT RATING:  600A  800A  1000A  1230A  1500A  2000A  2500A  3000A  3500A  Bus way or bus duct riser : is used for power distribution inside the

high building for each house

Eng : Amjed Osman

Building Electrical Design

IP PROTECTION  IP →Ingress Protection or International Protection IP is the number assigned to the electrical equipment and motors installed outside the building or in wall areas to protection from water and dust and object No 0 1 2 3 4 5 6 7 8

Protection form object and Protection form water dust Not protect Not protect Hand protect Vertical water Finger protect 15º Tool protect 60º Wire protect Splashing of water Dust protect Low jets of water Complete protect High jets of water Immession Complete submersible Eng : Amjed Osman

Building Electrical Design

TRANSFORMES  Types of transformer 1. steps up transformer 2. step down transformer

Types base on phase system  single phase  three phase Types of transformer base on poling  oil cooled transformer  air cooled transformer Eng : Amjed Osman

Building Electrical Design

TRANSFORMES  Note: for indoor transformer use air cooled transformer for outdoor transformer use oil cooled transformer in gulf countries the transformer are indoor type

installed in separate room ex substation room or transformer room  oil cooled transformer are not referred inside the building .  air cooled transformer are used inside building  unit of transformer is KVA Eng : Amjed Osman

Building Electrical Design

TRANSFORMES

 STANDARD RATING OF TRANSFORMER 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16)

50 KVA 60KVA 80KVA 100KVA 150KVA 250KVA 315KVA 500KVA 630KVA 800KVA 1000KVA 1500KVA 2000KVA 2500KVA 3000KVA 3500KVA Eng : Amjed Osman

Building Electrical Design

TRANSFORMES  Need of transformer Gulf countries Transformer is not require for building whose

total max demand less than 400kva If the total max demand is greater than 400kVA then we require transformer Max permit transformer size 2500kVA Sometimes is 3000kVA Eng : Amjed Osman

Building Electrical Design

TRANSFORMES  Steps to calculate the transformer size :

1.Consider Total max demand of MDB = KW 2.Total max demand of MDB in KVA = KW/cosø = KVA 3.Add 10% as future load Total max demand with future load in KVA = kVA ×1.10 4. Transformer size = Total max demand with future load in KVA Transformer load (90%)

Then select the standard size

Eng : Amjed Osman

Building Electrical Design

TRANSFORMES  Ex : calculate the Transformer size for project inside whose max demand is

100kw  Solution : Total max demand of MDB = 100 KW 1.Total max demand of MDB in KVA = KW/cosø = 100/0.8=125KVA 2. Add 10% as future load 3. Total max demand with future load in KVA =125 kVA ×1.10=137.5KVA 4. Transformer size = Total max demand with future load in KVA Transformer load (90%) = 137.5Kva/.90 = 157.7Kva  Standard T/F size = 250KVA / air cooled 11kv/440v / indoor T/F Y/▲ / z% = 5% 3ø, 4 wires 50 Hz Eng : Amjed Osman

Building Electrical Design

Capacitor bank  Types of load: 1.Resistive load: current is in phase with voltage 2.Inductive load: current lags voltage 3.Capacitive load: current leads voltage  Phase angle: angle between voltage and current  Note: All loads in our daily life are resistive – inductive loads, ex (tube light,bulb, motor and pumps ,w/h, w/m , r/c). Hence capacitor bank are required which are connected to MDB ,which improves the over all power factor of the system .  Sudan PF = 0.80 (low PF)  Final PF = 0.98 or 0.96 (improve p.f) Eng : Amjed Osman

Building Electrical Design

Capacitor bank Note  Capacitor bank is not require for single phase equipment or for

small project  Capacitor bank required for project involving three phase equipment or here phase motors or MCC panels and this capacitor bank is connected to MDB.  Unity of capacitor bank: KVAR (Kilo – Volt – Ampere – Reactive)

Formula to calculate capacitor bank:     

Capacitor bank (KVAR) Max demand of MDB in KW {tan(cos-¹ø1) – tan (cos-¹ø2)} Where Ø1 → initial power factor = 0.8 Ø2 → final power factor = 0.98 Eng : Amjed Osman

Building Electrical Design

Capacitor bank  Types of capacitor bank:

1.Fixed capacitor bank 2.APFC (Automatic Power Factor Corrector)  APFC: in this types the capacitor are automatic , they become on and off depending on the load  Ex: If full load then all capacitor are on If half load then few capacitor are on If no load then very few capacitor on

Eng : Amjed Osman

Building Electrical Design

standard capacitor bank 1. 10 KVAR 2. 15 KVAR 3. 20 KVAR 4. 25 KVAR 5. 35 KVAR 6. 40 KVAR 7. 50 KVAR 8. 75 KVAR 9. 100 KVAR 10. 125 KVAR 11. 135 KVAR 12. 150 KVAR 13. 175 KVAR 14. 200 KVAR 15 225 KVAR 16. 275 KVAR

17. 18. 19. 20. 21.

300 KVAR 375 KVAR 420 KVAR 540 KVAR 750 KVAR

Eng : Amjed Osman

Building Electrical Design

Capacitor bank

Eng : Amjed Osman

Building Electrical Design

EMERGENCY BACK UP SYSTEM  UPS / Inverter

(Un interrupted Power Supply)

 DG (Disel Generator )

or stand by generator

Eng : Amjed Osman

Building Electrical Design

UPS / Inverter  UPS →Un interrupted Power Supply

Eng : Amjed Osman

Building Electrical Design

UPS / Inverter UPS is used for back up of electronic equipment ,ex(computer, CCTV) Inverter is used for back up of electrical and electronic equipment's Ex → electrical (fans – lights - w/m ) Ex → electronic (computer – CCTV ) Unit of UPS/Inverter → KVA (Kilo – Volt – Ampere ) Eng : Amjed Osman

Building Electrical Design

Standard of UPS /Inverter 1. 0.5 KVA 2. 085 KVA 3 1 KVA 4. 1.4 KVA 5. 2 KVA 6. 3 KVA 7. 3.5 KVA 8. 5 KVA 9. 7.5 KVA 10. 10 KVA 11. 20 KVA 12. 25 KVA 13. 30 KVA 14. 40 KVA 15. 50 KVA 16. 65 KVA 17. 80 KVA 18. 100 KVA

Eng : Amjed Osman

Building Electrical Design

UPS / Inverter Step to calculate UPS/inverter size:

1.Calculate the total load in KW 2.Calculate the total load in KVA 3. UPS/Inverter size = total load in KVA UPS/Inverter loading = total load in KVA 0.80 (80% or 85% loading) 4. select the standard size

Eng : Amjed Osman

Building Electrical Design

UPS / Inverter  Wattages of load: 1. Tube lights = 40 w 2. Ceiling fans = 80 w 3. Computer

(a)CRT computer = 300 w (b)LCD computer = 200 w (c)LED computer = 160 w 4. printer = 200 w 5. router = 50 w 6. (6) EPBAX = 50 w 7. (7) CCTV = 50 w Eng : Amjed Osman

Building Electrical Design

Diesel generator The diesel generator can be connected in two methods

1.C.O.S (Change Over Switch ) manually operated switching 2. A.T.S (Auto Transfer Switch ) automatic switching Units of generator → KVA

Eng : Amjed Osman

Building Electrical Design

C.O.S (Change Over Switch ) manually operated

Eng : Amjed Osman

Building Electrical Design

A.T.S (Auto Transfer Switch ) automatic switching

Eng : Amjed Osman

Building Electrical Design

Diesel generator Standard generator size 1. 10 KVA 2. 20 KVA 3. 30 KVA 4. 40 KVA 5. 50 KVA 6. 63 KVA 7. 75 KVA 8. 100 KVA 9. 125 KVA 10. 132 KVA 11. 160 KVA 12. 200 KVA 13. 225 KVA 14. 250 KVA 15. 300 KVA

16. 400 KVA 17. 500 KVA 18. 600 KVA 19. 630 KVA 20. 750 KVA 21. 800 KVA 22. 1000 KVA 23. 1250 KVA 24. 1500 KVA 25. 1800 KVA 26. 2000 KVA 27. 2500 KVA

Eng : Amjed Osman

Building Electrical Design

Diesel generator Step to calculate generator size:

1.  Calculate the total load in kw = (SMDB Comm) 2. Total load in KVA = kw /cosø = KVA 3. Generator size = = total load in KVA generator loading (0.80) 4. Select the standard generator size

Eng : Amjed Osman

Building Electrical Design

Electrical instruments (testing and commission): 1. Voltmeter 2. Ammeter 3. Energy meter or Kwh meter 4. P.F meter 5. Frequency 6. Phase indicators 7. Multi meter Eng : Amjed Osman

Building Electrical Design

Earthing and lighting protection system  Earthing : connection of wire to the ground is knows as

earthing  Types of earthing conductor: 1.Earth continuity conductor (ECC) or protection earth conductor 2.Main earth conductor 3.Equipment bonding conductor 1.Earth continuity conductor (ECC) or protection earth conductor:  The earth wire passing to final loads and DB to SMDB or MDB is knows as ECC. 2.Main earth conductor:  The earth wire connected to ground is knows as main earth conductor usually it is connected to MDB. Eng : Amjed Osman

Building Electrical Design

Earthing and lighting protection system  3.Equipmential bonding conductor

Every metallic part in the electrical installation shall be connected to ground (earth)

Eng : Amjed Osman

Building Electrical Design

Earthing and lighting protection system  Types of earth pits:

1.Pipe earthing

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Building Electrical Design

Earthing and lighting protection system 2. Electrode earthing

Eng : Amjed Osman

Building Electrical Design

Lighting protection system  lighting protection system is building above 15 meter

Eng : Amjed Osman

Building Electrical Design

Lighting protection system

Eng : Amjed Osman

Building Electrical Design

lighting system  lamp → any device which gives light is knows as lamp  types of lamp:

1.Incandescent lamps

2.Fluorescent lamps a) CFL (compact Fluorescent lamps) b)tube

Eng : Amjed Osman

Building Electrical Design

Types of lamp 3.Mercury vapor lamps 4.Metal halide lamps

5.HPS(High Pressure Sodium)

6.Halogen lamps Eng : Amjed Osman

Building Electrical Design

Types of lamp Note:  Incandescent lamps are not recommended as their efficiency is very low (high input current , low output current  For indoor purpose the best lamps are fluorescent lampsas their efficiency is very good (less input current or power high out put light  The M.V lamps and metal ,HPS lamps are preferred for out door street light. Lamp input: is measured in watts  Ex : tube light(40w,36w) or CFL (24w , 36w) Lamp output: lamp output is measured in lumens . Eng : Amjed Osman

Building Electrical Design

Luminaire or lighting fixture  Lamp fixed on a frame or reflectors is knows as luminaire Illumination:

The lumen output of any luminaire falling on asq.meter room area is knows as illumination  It is measured is 1.Lux (Lx) if the room dimensions are in meter 2.Foot candle (F.C) if the room dimension are in feets Relation between LUX and F.C: 1 LUX = 0.1 F.C 1F.C = 10 LUX Eng : Amjed Osman

Building Electrical Design

Recommended lux level for different rooms by IENSNA  IENSNA: Illumination Engineer Society North America

Bedroom = 50 lux = 5 FC Hall = 150 lux = 15 FC Kitchen = 300 lux = 30 FC Bathroom =100 lux = 10 FC Coefficient of utilization (Cu): The Cu depends on the reflection factors of ceiling wall and floor colors . also it depends on the work plane height Note:  for manual calculation consider cu = 45%     

Eng : Amjed Osman

Building Electrical Design

Lamp lumen factor (LLF)  Lamp lumen factor (LLF) or lumen loss factor(LLF)

or maintenance factor (MF):  Ex : tube light (40 w)  Today → 2450 lumens  After 3 years→ less than 2450 lumens  The LLF depends on cleaning of luminaire Note  For manual calculation for 3 years maintence consider LLF= 0.67 Eng : Amjed Osman

Building Electrical Design

Formula  Formula to calculate no.of luminaire in room:

No.of lamps

=

(lux or FC)× room area ( luminaire )×(lumens ×cu × LLF)

 Cu = .45  LLF = 0.67

Eng : Amjed Osman

Building Electrical Design

Arrangement of luminaire: (x=2x)  X → distance from wall to luminaire  2X→distance between luminaire to luminaire

Eng : Amjed Osman

Building Electrical Design