TRADE PROJECT
ELECTRICAL INSTALLATION DESIGN OF TAITA TAVETA NATIONAL
POLYTECHNIC TUITION BLOCK
NAME: JOHNSON JUMA YERI
INDEXNUMBER: 115101/0227
PAPERCODE:
1601/
THIS RESEARCH PROJECT IS SUBMITTED TO THE KENYA NATIONAL
EXAMINATION COUNCIL (KNEC) AS A PARTIAL FULFILLMENT FOR THE
AWARD OF A CRAFT CERTIFICATE IN ELECTRICAL AND ELECTRONICS
ENGINEERING
MARCH 2024 SERIES
Page |
DECLARATION
I JOHNSON JUMA YERI declare that this project is my original work and I affirm that any
other institution for examination purposes has not presented this project.
Signature: _________________ Date: ________________
Declaration by the supervisor
This project has been submitted for defense with my approval as the Taita Taveta National
Polytechnic supervisor.
Signature: _________________ Date: ________________
Name: Mr.Mwadime
Page |
DEDICATION
I would like to dedicate this project to my wife and family who have always supported to me
throughout my life.
Page |
ACKNOWLEDGEMENT
I thank God for giving me the ability, knowledge and effort to complete this project. I also thank
Mr.Mwadime my supervisor who guided and motivated me all through the writing of this
project.
I would also thank the Head of Department (H.O.D) and entire administration through Electrical
and Electronics for their coordination and development of this project as well as provide
information on electrical design installation system in the building plan design.
Page |
TableofContents
DECLARATION..........................................................................................................................i
DEDICATION.............................................................................................................................ii
ACKNOWLEDGEMENT..........................................................................................................iii
CHAPTERONE...............................................................................................................................1
1.1INTRODUCTION..................................................................................................................1
1.2OBJECTIVES.........................................................................................................................1
1.3SCOPE....................................................................................................................................1
1.4LIMITATIONS.......................................................................................................................1
1.5BLOCKDIAGRAM................................................................................................................2
1.6METHODSOFWIRING.........................................................................................................3
1.7SPECIFICATION...................................................................................................................3
CHAPTERTWO..............................................................................................................................4
2.0BUILDINGDESCRIPTION...................................................................................................4
CHAPTERTHREE..........................................................................................................................5
3.0ELECTRICALDESCRIPTION..............................................................................................5
3.1METHODOFWIRINGTOFITTINGS....................................................................................6
3.2FLUORESCENTFITTINGS...................................................................................................6
3.3SECURITY.............................................................................................................................6
3.4SPACEFACTOR....................................................................................................................6
3.5TERMINATION.....................................................................................................................7
3.6TESTING AND COMMISSIONING………………………………………………...……..7
3.7LIGHTINGLEVEL&POWERINSTALLATION...................................................................7
CHAPTERFOUR............................................................................................................................9
4.0MATERIALSREQUIREMENTS...........................................................................................9
CHAPTERFIVE............................................................................................................................10
CONCLUSION..........................................................................................................................11
RECOMMENDATION.............................................................................................................11
SAFETYPRECAUTION...........................................................................................................11
REFERENCES...........................................................................................................................11
Page |
Page |
CHAPTER ONE
1.1 INTRODUCTION
The project entails the design switched gear of the new tuition building installation. The
incoming three-phase power supply comes underground to the distribution board that will be
located to appropriate accessible position.
From the distribution board, sub-main cables are taken to industrial socket outlet via isolator
while the cables are taken to the consumer unit i.e. Circuit breakers and find socket outlet fan
and lighting circuit connect from consumer unit. The electrical installation will be designed to
meet the requirements at I.E.E wiring regulation and British Standard (BS: 7671:2008).
1.2 OBJECTIVES
The main objectives of the project are;
To provide electrical services such as lighting power system, power system and security
lighting.
To provide entire protection of the equipment’s and the building.
To provide mechanical and electrical control to the equipment’s.
1.3 SCOPE
The project tends to detail the design of installation wiring system which will be consists of
distribution board, sub main cables, isolators, industrial socket outlet, circuit breakers and final
circuit operations testing and commissioning so that ensuring safety of installation wiring system
and the building is achieved according to the I.E.E regulations.
1.4 LIMITATIONS
In case of faulty or short circuit, the circuit breakers may fails to trip off quickly result to fire
appliances and electronics can be potentially damage.
The use of more than one type of wiring system makes the project more expensive.
Page |
1.5 BLOCK DIAGRAM
Figure1.1
Three Phase
Incoming Distribution Consumer
Final Circuit
Power Board Unit
Supply
Isolator
Industrial
Socket Outlet
1.5.1 Brief description of the block diagram
Power supply
The three-phase power supply 415v, 50Hz comes from transformer within the institution power
supply.
Distribution Board
The floor duct, steel wire armored cables will be used from the incoming power supply to the
distribution board.
Isolator
The sub main cables coming from the distribution board runs through steel trunking to the
isolator via P.V.C conduit to the industrial socket outlet.
Page |
Consumer Unit
The sub main runs in steel trunking from the distribution board through PVC conduit to the
consumer unit.
Final Circuit
Different final circuits are connected from the circuit breakers within the consumer unit by the
use of P.V.C conduit wiring system including socket outlet, lighting switch and fan switches.
1.6 METHODS OF WIRING
Steel Trunking Wiring System
The steel trunking (100mmx50mm) will be mounted around the surface of the walls one feet
above the floor.
PVC Conduit wiring system
The P.V.C conduit (Heavy gauge) of 32mm2will be erected in the walls connected to industrial
socket from the steel trunking while P.V.C conduit 20mm2connected from consumer unit.
PVC Trunking Wiring System
The PVC mini-trunking 25mmx16mm will be runned from steel trunking to the consumer unit
that supplies single-phase low voltage.
1.7 SPECIFICATION
Power supply 415V 50Hz Three phase
Isolator fuses 32A rated
Consumer Unit 100A rated
Circuit Breaker 32A rated
Circuit Breaker 6A rated
Circuit Breaker 15A rated
Socket Outlet switch 13A rated
Page |
CHAPTER TWO
2.0 BUILDING DESCRIPTION
The tuition building surface area will be 70.4m by 12m with the height of 3m above.
The colour of building will be painted cream white inside and outside walls with black skirting
colour outside walls above1½ feet from the ground.
Page |
CHAPTER THREE
3.0 ELECTRICAL DESCRIPTION
Armoured Cable
The incoming power supply from the service through underground will be PVC/SWA/PVC are
made stranded copper conductors. The cables will be rated at 600-1,000volts grade to BS6, 346.
Distribution Board
The distribution board of the surface/flush mounted metal enclosure type complete with RCBOs
(ResidualCurrentBreakerOver-current) with trip rated will be specified. Each distribution board
is complete with hinged lid and so constructed that the circuit breaker toggle are concealed when
the lid closed.
Consumer Unit
The consumer unit of the surface mounted metal and PVC enclosure type complete with MCBs
(Miniature Circuit Breaker) and isolation switch.
Trunking/Mini-Trunking
The steel trunking and PVC Mini-trunking will be installed and mounted on the surfaces of the
walls horizontally and vertically respectively.
Conduit
The P.V.C conduits type, heavy gauge will be concealed in the walls from trunking to the
industrial socket outlets via isolator and from trunking to consumer unit where the final circuits
are connected such as socket outlets, fan and light circuits.
Industrial Socket outlet
The industrial socket outlets will be powered by three-phase supply from the distribution via
isolators.
Page |
Socket Outlets
The socket outlets will be installed in ring final circuit connected with circuit protective
conductor (C.P.C)
3.1 METHOD OF WIRING TO FITTINGS
The lighting/fan fitting with1.5mm two single core P.V.C cables. The final connection to all
fittings carried on heat resisting cables.
The socket outlet fittings cables will be 2.5mm2 three-core PVC cables. The industrial socket
fittings will be 4mm2 three-core cables. Three live cables, neutral cable and earth cable for the
industrial socket outlets.
The sub main cables runs from distribution to the isolator and consumer unit will be 6mm2 and
4mm2 respectively.
The lightning switch and boxes will be surface mounted and fitted with approved flush conduit
box.
Rotary fan switch will be surface mounted.
3.2 FLUORESCENT FITTINGS
The twin fluorescent tube will be two feet suspended from the plaster ceilings rose. Each fitting
is power factor corrected to 0.9 and provided with starting devices.
3.3 SECURITY
The two high sodium vapour type will be mounted on the walls from and back of the building
respectively.
The two-tungsten halogen lamp type will be mounted on the walls front and back of the building
respectively with power factor lagging of O.9.
3.4 SPACE FACTOR
The maximum number of cables that should accommodate in given size of conduit or trunking
should not exceed the number in table B5 and B6 as stated in regulation B91, B17 and B18 of the
I.E.E regulation to whichever appropriate.
Page |
3.5 TERMINATION
All single core cables connected to the junction and terminals in the ceiling rose should be
mechanical and electrical sound.
3.6 TESTING AND COMMISSIONING
The design of electrical installation wiring system including testing and commissioning that is
testing before/after of entire electrical installation to ensure they are in a good working condition
to satisfaction of engineers and customer.
The tests that shall be carried out are;
a) Polarity test
b) Insulation resistance
c) Continuity test
d) Earth loop impedance
3.7 LIGHTING LEVEL&POWER INSTALLATION
The lighting fittings in the building would be determined by calculation based on recommended
illumination levels for operations. The illumination levels will be as follows;
E1 E2 E3
3m 3m 3m
R
2.4m 2.4m 2.4m 2.4m
R2= √ 32 +2.4 2 = √ 14.76
R=3.84
lm of twin tube=1300lm
1cd =4πlm
=1300lm
Page |
1cdx1300 =103.45cd
4πlm
E1 =103.45xcos.3/3.84
(3.84)2
E1 =103.45x0.9999 =7.0lm/m2
14.75
E1 =E3≠E2
(7.0x2)=14.0lm/m2
E2=103.45cos0=103.45 =11.5lm/m2
32 9
(E1+E2+E3)= (7.0+11.5) =18.5lm/m2
Lumen Received By the Ground
ᶲ=EpxA
Ep=E1+E2+E3
ᶲ=18.5lm/m2x844.8m2
ᶲ=15,628.8lm
ᶮ=Lumen Received
Lumen omitted
ᶮ=15,628.8lm = 15,628.8 =0.28
(1,300x43) lm 55,900
Total Actual Lumen Received by the Ground
ᶲ=ExA = 18.5x844.8
ᶮxP 0.28x0.8
Totalᶲ= 15,628.8 =69,771.43lm
0.224
Page |
CHAPTER FOUR
4.0 MATERIALS REQUIREMENTS
a) Distribution Board
b) Consumer unit
c) Isolator
d) Industrial socket outlets
e) 3gang 2way switch
f) Steel Trunking and PVC mini-trunking
g) P.V.C Conduit
h) Switch Box
i) Fan switch/Rotary fan switch
j) Fluorescent tube an fittings
k) Twin socket outlets
l) Earth rode
m) Complete ceiling rose
Page |
CHAPTER FIVE
Project Materials Cost
No. Materials Quantity Cost/Unit Total
Cost(Kshs.)
1. Steel trunking x10 1,000 10,000
(100mmx50mm)3m
2. Isolator 32A x5 2,500 12,500
3. Distribution board 12 way x1 6,500 6,500
4. 4 way consumer unit x2 2,600 5,200
5. Industrial socket outlet x5 800 4,000
6. PVC conduit
Heavy conduit 32mm2 3mx10 200 2,000
7. PVC conduit
Heavy conduit 20mm2 3mx20 130 2,600
8. PVC mini-trunking
(25x16mm) 3mx2 150 300
9. Twin Socket x66 300 19,800
10. 3gang 2way switch x11 250 2,750
11. Switch boxes x74 30 2,220
12. Fan & Rotary switch x4 3,500 14,000
13. Twin fluorescent x43 1,500 64,500
tube1300/m
14. PVC–sheathed cable
Single core 6mm2 40mx5 100 10,000
15. PVC–sheathed cable
Single core 4mm2 10mx5 80 4,000
16. PVC–sheathed cable
Single core 2.5mm2 45mx5 35 7,875
17. PVC–sheathed cable
Single core1.5mm2 70mx5 25 5,250
18. Earth rode(25mm2) x1 2,500 2,500
19. Couple ceiling rose x13 180 2,340
TOTAL 178,335
Page |
CONCLUSION
The goal of the project was to design and installing wiring system to the entire building.
After analyzing the whole project systematically the installations was designed and installed.
Testing and commissioning results showed the design was successful.
RECOMMENDATION
The project after have been proved to be successful, it is advisable checking and maintenance of
entire wiring system periodically.
In case of worn out of materials such as cable insulation, melting of MEB or short-circuited
replacement and test must be done approximately according to I.E.E regulation requirement.
SAFETY PRECAUTION
Warning precaution on high voltage three phase exists.
Settling rules and regulations
Should wearing personal protective equipment during maintenances
REFERENCES
Electrical installation work 9thedition by Brian Scaddan.
Page |
