1.electrical cables-are made of copper, aluminum or silver and are used in transmission of electricity.

Cables can be overhead, underground or service (flexible and flat cables). Other types include coaxial,
shielded and ribbon electric cables.

2.electical pipes and fittings-are used to protect and route the electrical wires and can either be metal,
plastic or flexible.

3.electrical circuit breakers-they protect against electrical overload and fires by cutting the transmission
by burning up.

Electrical tapes-this one’s insulate wires preventing electric shocks

Electrical cable ties – organise and secure cables and wires

Electrical box-houses cables assuring safety

Electrical connectors

Electrical accessories

Are items used in domestic and industrial electrical wiring. They include:
 Sockets-can be of different types such as industrial sockets(15A) and MF industrial
sockets(3 phased)
 Switches – are used to regulate current flow, either put on or off
 Junction-this are termination points and which allow current to be transmitted in any
intended direction
 Alarm accessories – they alert whenever a fire outbreak occurs this ensuring safety
 Switch fuse outlets
Electrical safety and precautions
This are essential from preventing one against electrical hazards such as burns and
shocks. They include:
 Protect live wires by use electrical pipes and fittings
 Never put fingers or objects in socket outlets Always be in your
PPES during operation
 Keep metals away
 Never work or operate in wet ares to avoid risk of shocks
 Never pull a plug out by its cord
Electrical PPES include
 Safety glasses
 Insulating gloves
 Safety shoes
 Flame resistant clothes
 Face shields
Electrical symbols
Essential in any electrical project and are as below
Pi”c”cccccccccccccccccccccccccc(phone)
Electrical tools
Used in electrical installations and include, pliers used in cutting and fixing wires
Testers-checks availability of electric current
Cable clips-holds cables tightly
Electrical knife-strips off outer wire cover
Ball pen hammers – used in driving cable clips
Measuring tapes-takes desired measurements
Screw drives-drives bolts
Wire cutters
Discussion
Factors to consider when choosing the type of installation to do are
Loading conditions
Cable sizes
Protection of cables
Location
PRACTICAL EXERCISE
Final circuit installation
The below plan was required
Piccccccccccccccccccccc(phone
Tools required
Pliers
Electrical knife
Bulb holder
Cables
Tester
Measuring tape
Screw driver
Ball pen hammers
Cable clips
Procedure followed was as below
Main switch connection
Making of junction
Designing of socket outlet point
Making the switching point
Finally installing the lamp point where the bulb was inserted
All the above were interjoined using measured cables as per the plan
Below is the layout that we came up with,
Piccccccccccccccccccccc(bony
Discussion
Always leave allowances to wires for easy repair in case of burns on wires
Planning should be as stipulated at any given point
Ensure to use cable clips after joining the wires
In case of live wires use tapes to cover them
Be in correct PPES always

References
Class notes
Online research
Cite a book

6.AUTOMOTIVE WORKSHOP
Essentially deals with study of the engine including the engine components and how the
systems work.
The major engines components are,
I. Engine block-has the piston and cylinders
II. Cylinder head-closes the of the cylinder. The cylinder head seals the cylinder
block and blocks entry of exhaust gases back into the cover head.
It also houses other engine components such as spark plug, valves and injectors
III. Oil sump casing- found at the bottom of the engine and has oil resourvoir. Oil is
pumped from this point to other engine parts.

Others include,

Injector pump-introduces and atomises fuel(diesel) into cylinder and manages timing
from point of fuel ignition, injection and combustion

Crankshaft-converts reciprocating motion of piston into rotary motion of the crankshaft

The size and shape of the crankshaft is dependent on the number of existing cylinders

Piston-fitted into each cylinder to transmit thrust to connecting rod and gives tight seal
to cylinder by use of piston rings and oil rings around it

Piston rings-allows pistons to move freely up and down the cylinder and provides the
piston with good sealing to avoid gas escaping, likewise to frictional rresistanc

Connecting rods-connects piston to crankshaft and transmits motion from piston to

crankshaft in that it converts reciprocating motion of piston into rotary motion of
crankshaft

Camshaft-controls opening and closing of both the inlet and exhaust valves

Flywheel-rotates the crankshaft during beginning of a stroke. This is possible as the

flywheel stores excess energy produced from power stroke for consumption by other
strokes

Crankcase-offers base for attachment of cylinder and serves as part of lubricating the
engine system

Rocker arm shat-holds the rockers in place

Carburretor-converts petrol into fine spray and mixes the fuel with air in correct
proportion. Only found in petrol engines. In diesel engines this is replaced with the
injector pump

Camshaft-operates the valves I. E in opening and closing

Piccccccccc

Push rod-moves up and down in relation to movement of the camshaft to help in

opening and closing of the valves

Oil filter-removes oil particles before oil is puped and circulated to the whole engine.

Oil rings-found at the top most end of the piston and are used in oil transmission to
other engines. The rings are positioned in such a way that the splits are not aligned so
that oil can’t escape.

End cap-it’s in between the cylinder head and engine block and prevents mixing of water
and oil by separating the outlets involved in transmission

Spark plug-used in petrol engine to ignite compressed air fuel mixture

Valves-of two types, the intake and exhaust valves. The valves open and close to allow
entry of air fuel mixture and emit exhaust gases respectively.

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TYPES OF ENGINES

Engines can be of two types with reference to the number of strokes involved and the
type of fuel used as below,

I. Four stoke engine

Found in vehicles and other complex machines
The four strokes below are arranged systematically as they occur and include,
Induction stroke
Here the piston moves from dead center to bottom dead center
Inlet valve opens
Air fuel mixture is drawn into the cylinder
Compression stroke
Piston moves from bottom dead center to top dead center
Both inlet and exhaust valves are closed so that air mixture can’t escape
Now the air mixture is at high temperature and pressure
Power stroke
Spark is introduced by spark plugs into the compressed air fuel mixture
Piston moves from top dead center to bottom dead center
Both intake and exhaust valves are closed
Exhaust stroke
Piston moves from bottom dead center to top dead center
Exhaust valve opens to expell exhaust gases to the atmosphere
 As the piston approaches top dead center, the exhaust valve closes and inlet
valve opens to let air fuel mixture in
The process is again repeated
Ii. Two stroke engine
Found in less complex machines such as motorcycles
Diesel is used as the fuel
The diesel is not mixed with air.
Below are the systematic strokes involved
Induction stroke
Inlet valve opens
Air is drawn into the engine
Compression stroke
Piston moves from bottom dead center to top dead center
Both exhaust and inlet valves are closed
Air is compressed

The injector pump is used to pump diesel into injector which is used in place of spark plugs. The injector
pump atomises the fuel

Power stroke

Atomised fuel is introduced into the compressed air

A spark is introduced and burns the fuel

Piston moves from top dead center to bottom dead center

Both intake and exhaust valves are closed

Exhaust stroke

Piston moves from bottom dead center to top dead center

Exhaust valve opens to expel exhaust gases

As it approaches top dead center exhaust valve closes and inlet valve opens to let in air

The engine is made up of various systems such as,

Combustion system
Cooling system
Transmissions system
Braking system
Lubrication system
 Electrical system
We shall discuss all the above in a detailed form
I. Combustion system

This system ensures power is transmitted to run the engine and occurs in strokes which were discussed
as above. They ot the following types,

a. Spark ignition system

Uses petrol as fuel
b. Compression ignition system which uses diesel as fuel as it does heavy
operations hence needing high output power

Ii. Cooling system

Since most parts of the engine are made up of metals which are good conductors of heat, the engine
heats up and therefore this system is needed in cooling the engine for optimum working conditions

The cooling system is further subdivided into two systems which include

Air cooling system

This system has fins which are high in number to increase the surface ares over which heat is absorbed.
The fins work in such a way that cold air passes through the fins and carries away hot air as a result of
reaction of the piston and cylinders.

If the engine is stationary a fun is provided.

Water cooling system

The system has components such as,

Radiator-has coolant(water) and fins to helb in absorbing heat

Water pump-pumps water from the radiator to the engine

Fun – rotated by the engine and helps in cooling engine

Hose pipes – connects the engine to the radiator

Thermostat-this is a temperature sensor of the coolant

Electrical system

The system is responsible for processes such as,

Charging

Igniting the engine

Starting the engine

Lighting purposes

Has a battery which has a fuse box and four rated fuses
The electrical system is further classified into,

Ignition system – has a capacitor to store charge

Charging system-has an alternator which charges the battery and controls the charge I. E if greater than
12V charging is discontinued

Starting system-has a starter motor which is directly connected to the battery which acts as the ignition
key

Lightning system-the system operates parts such as brake lights, parking lights, head lamps, indicators,
wipers, powered windows, powered doors, radio systems and horns.

BRAKING SYSTEM

Below are some of the systems components

Brake pedals-connected electrically to brake lights

Master cylinder-has brake fluid(resouvouir) and booster which provides pressure

Brake pads-found in the front wheels to help in braking

Brake shoes and drums-found in the back wheels for braking

Piston – is spring loaded and helps in pressure transmission

Breaking mechanism

Brake pedal is pushed forward by use of one’s foot during braking and pressure applied to the pistons
which push the brake pads . This pressure from the brake pads in turn pushes the brake fluid which
pushes the piston thus the brake shoes, which in turn push the brake drums. The brake drums rotate in a
direction opposite to that of the wheel hence motion is thus halted after they press on the wheels.

TRANSMISSION SYSTEM

This system is involved in entirely transmitting power produced thus enabling motion of the machine.

Some of its components are

Engine-this is the prime mover

Gear box-regulates the speed of the vehicle

Propeller shaft –delivers torque from transmission to differential

Differential unit-transmits torque from the Propeller shaft to the wheels

Wheels-receives torque from the differential unit and in turn rotates thus moving the machine

Pressure plate-applies pressure to the clutch disc for transfer of torque to transmission

Flywheel-stores mechanical energy to ensure that engines performance is not altered

Clutch plate-is in between pressure plate and flywheel and has female spines which mesh with male
spines to connect engine with the gear box.

The precession of torque in the transmission is as follows,

Engine-gearbox-propeller shaft-differential unit-wheels

LUBRICATION SYSTEM

This system is involved in lubricating the entire engine system by use of oil for ensuring smooth
operations and minimizing friction between moving parts to prevent wear and tear.

Below are some of the systems components and their use,

Sump-stores oil

Strainer-filters oil before being taken into engine thus removing bigger solid particles present which if
allowed to enter the engine might cause clogging

Oil filter-filters smallest particles present in the oil

Oil pump-pumps oil through the whole engine through the strainer then to the filters and finally to
engine parts

End cap – in between the engine block and the cylinder head.the end cap prevents oil from mixing with
water.

PRACTICAL EXERCISE

Disassembling and assembling of engine

Tools required

Spanners of different sizes

Ratchet

Screw drivers

Disassembling procedure

Using Spanners, ratchets and screw drives dismantle the engine beginning from the cylinder head, then
the engine block and finally the oil sump

During Disassembling note the positions of various parts of the engine.

All nuts and bolts should be kept safe

Pi”ccccccccccccccccccc

Assembling procedure

Collect all the assembling tools required such as Spanners and Screw drivers
Begin fitting the last Disassembled part to the first one i. e install oil sump, then the engine block and
finally the cylinder head

Ensure that the engine parts in both the cylinder head, engine block and the oil sump are correctly fitted
into positions as previously during disassembling

During fittings nuts and bolts should be tightly fixed

The end result was as below

Piccccccccccccccccccc

Discussion

When assembling always tighten bolts and nuts where necessary for firmness of the engine parts to
avoid minor injuries during other services

Always note the original positions of engine parts before assembling to avoid mix ups

Conclusion

The engine should be serviced regularly for proper and higher performances

Engine parts should be lubricated for smooth operations and longer life span

Recommendations

The school administration should provide the automotive sector a more modern engine for study since
the world is evolving and new ideas ought to be emulated.

References

Class notes by Mr. Ogolla

Automotive textbook by Chand

Online research

CARPENTRY WORKSHOP

Is a process that involves working with wood to create, construct or repair structures

It’s also a craft that combines precision, creativity and craftsmanship and also allows one to transform
raw materials into structures and designs

Application of carpentry

Construction, industries, project working, residential homes building,commercial buildings

Tasks involved in carpentry

Framing, furniture making, finishing work, grooving and cutting among others

Products from carpentry

Furniture – Tables, beds, windows, shelves

Wooden structures-wooden boards

Hardwood flooring

Roofs-done by roofing.

Cabinetry-kitchen cabinets, bathroom cabinets

Types of woods used in carpentry

Various types of woods are preferred for various operations based on their characteristics, such woods
include

Camphor

Eucalyptus

Cypress

Jacaranda

Wood sizes

Measured in inches.

3 by 2,4 by 2,6 by 2,8 by 2 inches up to 12

Safety precautions in the carpentry workshop

Used saw dust to cover areas spilled with oil to avoid injuries from falls

Always be in your PPES during operations

Never lean on machines when they are on

Only one person should operate a machine at a time unless help is needed

Always work is a spacious environment

Used tools that are in good working conditions

Don’t operate machines if in any kind of stress or discomfort

Don’t test sharpness of objects using bare hands

Carpentry PPES and uses include,

Helmets-prevent head injuries from falling objects

Ear muffs – cover ears from extreme noise

Safety boots-protects legs from injuries by heavy landing objects

Carpentry tools and their uses include,

Tape measure-takes measurements in mm, cm or feets

T square-checks whether surfaces are right angled

Pencil-used in marking

G clamp-holds wood workpieces in place for easier operations

Saw-can be cross, rip or hack saw and are used in cutting

Wood chisels-used in making desired holes on woods or grooving

Hammer-used in driving nails or unhooking nails

Drill bits-used in making holes on woods

Planes-used in smoothening rough wood work and of different types ranging from number 5 to number
3

Spoke shave-smoothen curvatures

Rasp-either round or flat filed and are used in filing

Sash clamp – used in holding wood work pieces together

Hand drill-simple drill that is hand driven to make drills on holes

Set of saws – is a collection of saws

Saw set – sets saw teeth into place

Folding rule – used in taking measurementa

Piccccccccccccccccccc.

Carpentry machines include,

Carpentry machines play a crucial role in woodworking and can greatly enhance productivity and
precision.

1. Mortise Machine: A mortise machine is used to create square or rectangular holes, called
mortises, in wood. It typically consists of a chisel and a drill bit that work together to remove
material and create the desired hole.

2. Wood Lathe: A wood lathe is a machine used for shaping wood into various forms such as bowls,
table legs, or spindles. The wood is rotated on the lathe, while cutting tools are used to shape
and carve it.
 3. Circular Table Saw: A circular table saw is a versatile tool used for making straight cuts in wood. It
consists of a circular blade that protrudes through a slot on a flat table. By adjusting the angle
and height of the blade, different types of cuts can be achieved.

4. Band Saw: A band saw uses a continuous band of toothed metal, or a blade, to cut through
wood. It is commonly used for making curved or irregular cuts. The blade runs on two pulleys,
creating a continuous loop.

5. Surface Planer: A surface planer, also known as a thickness planer, is used to flatten and smooth
rough lumber. It consists of rotating blades that remove thin layers of wood from the surface,
resulting in a smooth and uniform finish.

These machines, when used skillfully and safely, can greatly aid in carpentry projects by increasing
efficiency and ensuring accuracy in the woodworking process.

Piccc”cccc. Cccccccccccccccccccc

PRACTICAL EXERCISE

Making a machine standing rack – the profile is as below

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Procedure in making a machine standing rack

Calculating the bill of material and total cost of the intended work before initialisation which includes
wood needed in inches and the quantity, nails needed likewise to the labour

The bill of materials(BOM) calculated was AS below

Piccccccccccccccccccc. (phone)

Collecting the required wood

Preparing the wood pieces by use of machines to smoothen the surfaces and cut them into required
quantity

Assembling the tools and laying out the given plan

Fix the wood parts by use of nails to provide firmnesa

Below is the completed task

Piccccccccccccccccccc.

Discussion
Always follow all the safety measures stipulated while doing operations

Handle machines with care

Conclusion

Carpentry is a timeless skill that should be highly practiced at any given point, an engineer should be
equipped with such skills

References

Class notes by Chief technician Mr. Talum

Online research

PLUMBING WORKSHOP

Plumbing-