BUILDING ELECTRICAL SYSTEMS DESIGN & DRAFTING
Engineer : AMJED OSMAN ELSAYED
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 .
Generation , transmission and distributions of electrical energy
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
230/400V
Distribution Substation
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
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
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 ).
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
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
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
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
Types of Switch One way switch
Two way switch
Intermediate switch
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
Gang four gang 4G
five gang 5G
six gang 6G
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
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)
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
Equivalent of mm² to AWG MM² 1.0 mm² 1.5 mm² 2.5 mm² 4 mm² 6 mm² 10 mm² 16 mm² 25 mm² 35 mm² 50 mm² 70 mm² 95 mm² 120 mm² 150 mm² 185 mm² 240 mm² 300 mm²
AWG 18 AWG 16 AWG 14 AWG 12 AWG 10 AWG 8 AWG 6 AWG 4 AWG 2 AWG 1 1/0 AWG 2/0 AWG 3/0 AWG 4/0 AWG 250 kc MIL 350 kc MIL 400 kc MIL 500 kc MIL
REMARK AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA AWG For KSA
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)
CORE OF CABLES (b) Three core cable (3c)
(c)Four core cable (4c)
(d)3 ½ core or 3.5 core
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)
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
16 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
Conductor materials :
1. Copper (cu)
2. Aluminum (al)
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 .
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
Types power cable : 1.Un armoured cable
2. Armoured cable
c)
SWA (Steel Wire Armour ) AWA(Aluminum Wire Armour) SSA (Steel Strip Armour )
d)
ASA (Aluminum Strip Armour)
a) b)
Voltage classification :H.V → High Voltage (above 1000 v) 2. M.V → Medium Voltage (250 to 1000v) 3. L.V → Low Voltage (30 to 250 v) 4. 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. 1.
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
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
Electrical faults Types of electrical faults : Over load Short circuit Earth –fault or shock Over voltage Under voltage
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.
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
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
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
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
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
Standard C.B Rating 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)
Standard short – circuit rating of C.B : 1. 6KA 2. 10KA 3. 6KA 4. 25KA 5. 35KA 6. 50KA Example
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
Types of MCB B curve MCB
C curve MCB
D curve MCB
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 ).
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
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
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
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 100mA 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
Working principle of RCD No .of poles : Since neutral is compulsory in RCD we have
1. Two poles RCD
2. Four poles RCD Examples
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
RCCB or RCBO Ex : (C 40A - 100ma
- 10KA)
C → type of MCB 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.
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 Important 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
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
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
Conduit: (electrical pipe) Material of conduit : PVC
Metallic
GI/GS→ Galvanized Iron/
Galvanized Steel
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
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.
Conduits accessories: Coupler : coupler used to join 2conduts
Bends : In gulf countries bends are made
at site in the same coduit using PVC bending
Junction box (JB) or pull box (PB) : There are 2 types of JB
1. Circular JB (used mostly in Sudan and BS) 2. Octagonal JB (used in KSA)
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
Junction box octagonal JB
back bax : are used for s/o flex outlet etc
adapter : use for fixing conduit to the back box
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
conduiting laying of conduit is knows as coduiting there are three stages for
conduiting . conduiting in slab
conduiting in wall
conduiting in floor
Cable trunking Cable trunking is used to carry branch of wires (many wires )
Materials' :
1. PVC cable trunking 2. Metallic cable trunking
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
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
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
Materials of cable tray: 1. No PVC 2. Metallic (a) Galvanized cable tray
(b) Hot dip galvanized cable
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)
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 )
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 )
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
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)
Types of HVAC system 1. Window A/C
2. Split A/C
3.VRV or VRF system
Types of HVAC system 4. Package A/C
5. Central A/C – VAV system
6. Chilled water system
Plumbing system 1. Water supply
2. Central hot water system
3. Drainage system
Plumbing system Fire fighting system
Duty and stand by pumps
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.
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
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.
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
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
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
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
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
TRANSFORMES
STANDARD RATING OF TRANSFORMER 1) 50 KVA 2) 60KVA 3) 80KVA 4) 100KVA 5) 150KVA 6) 250KVA 7) 315KVA 8) 500KVA 9) 630KVA 10) 800KVA 11) 1000KVA 12) 1500KVA 13) 2000KVA 14) 2500KVA 15) 3000KVA 16) 3500KVA
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
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
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 / oil cooled 11kv/440v / outdoor T/F Y/▲ / z% = 5% 3ø, 4 wires 50 Hz
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 = .98 or .96 (improve p.f)
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
Capacitor bank standard 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
EMERGENCY BACK UP SYSTEM UPS / Inverter
(Un interrupted Power Supply)
DG (Disel Generator )
or stand by generator
UPS / Inverter UPS →Un interrupted Power Supply UPS is used for back up of electronic equipment
,ex(computer, CCTV) Inverter is used for back up of electrical and
electronic equipments Ex → electrical (fans – lights w/m ) Ex → electronic (computer – CCTV ) Unit of UPS/Inverter → KVA (Kilo – Volt – Ampere )
UPS / Inverter Standard of 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
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
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 Transformer Switch ) automatic switching Units of generator → KVA
Diesel generator Standard generator size 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
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
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.
Earthing and lighting protection system 3.Equipmential bonding conductor: Every metallic part in the electrical installation shall be connected to ground (earth) Types of earth pits: 1.Pipe earthing 2.Electrode earthing 3.Plate earthing
Lighting protection system lighting protection system is building above 15 meter 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
Types of lamp 3.Mercury vapor lamps 4.Metal halide lamps
5.HPS(High Pressure Sodium)
6.Halogen lamps
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 .
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
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= 0.45%
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
Formula Formula to calculate no.of luminaire in room: No.of luminaires = illumination (lux or FC)× room area ( No .of lamps /luminaire )×(luminaire×cu×LLF)
Cu = .45 LLF = 0.67
Arrangement of luminaire: (x=2x) X → distance from wall to luminaire 2X→distance between luminaire to luminaire
