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Definition

AirConditioner

Types

Central UnitUnitary Systems

Remote Split

Operation

IEE regulations

Installation &Wiring

Maintenance &Troubleshooting

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Definition : simultaneous mechanical control oftemperature, humidity, air purity & air motion. It

include the process of extracting the warm &dirty atmosphere from enclosed area thatcombine the use of air filter & refrigeration plant.

Why do we need Air Cond?- To improve the control of industrial process.

- To maintain human comfort

- Hospital operating Suites - reduceinfection risk and humidity controll.

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Types of domestic air conditioning

1.Central Unit Systems

- Compressor, condenser,evaporators and expansion valve isplaced in one close location & the

cooling tower is located outside of it .- Cool air is piped out from

evaporators in air monitoring room tothe space to be air conditioned. Thissystem is used at hotels, shoppingcomplex and big building

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Fourth level Fifth level

Central Unit Systems

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2.Unitary Systems

- In this system, factory assembled airconditioners are installed in oradjacent to the space to beconditioned. The unitary airconditioning systems are either self-contained system such as window

units and packed units, or remotesplit systems.

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3.Remote Split System

These systems are in more common use in theresidential and small commercial installations.

They have the evaporator, blower and furnacelocated in a closet in an equipment room withcondensing unit.

The refrigerant is piped from the condensing unit

to the indoor coil through copper tubing. The airis ducted from the air conditioning equipmentto the space to be conditioned.

Most residential units have the indoor section

centrally located within the space, whicheliminates the need for a return air ductsystem.

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Unitary Systems

SelfContainedSystem

Air-

cooledsystems

Water-

cooledsystems

Window Units

Packed

Units

WaterCooled

AirCooled

Remote Split System

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Window unit Advantages

1. Separate temperature control foreach unit in an enclosed area.

2. No need of Air tubing. Reduce cost.

3. Piping work is no need.

4. Easy installation but unremovable.

Window unit Disadvantages

1.

Need special area at the window.2. Air quantity decide by the factory.

3. Unit installed at the wall. So needto break the wall structure.

4. If failure occur, it is not easy tobring the unit down individually.

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Window unit Advantages

1. Sebuah bilik menggunakan sebuahunit penyamanan udara yangmengawal suhu secara berasingan.

2.

Salur udara tidak diperlukan.Menjimatkan kos.

3. Kerja pempaipan tidak perlu.

4. Pemasangan adalah mudah tetapipemasangan kekal (tidak boleh ubah)

Window unit Disadvantages

1. Memerlukan ruang tertentu padasesebuah tingkap.

2. Kuantiti udara biasanya ditentukanoleh pengeluar.

3. Unit dipasang didinding, jadi dindingterpaksa dipecahkan.

4. Sekiranya berlaku kerosakan, sukarmenurunkan unit secaraberseorangan.

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Remote Split System Advantages

1. No need of air feeder.

2. No need of water piping work.

3. Easy installation.4. Suitable for user that desire to

install heater & conditioner athome.

Remote Split System

Disadvantages

1. Difficult to do maintenance iffailure occurred.

2. Have indoor and outdoor unit.

3. Need speacial space.4. Installation cost is expensive.

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Split unit air conditioner system that separate theevaporator and condensor unit.

This unit divided to TWO are :-Indoor and Outdoor unit.

Indoor unit installed in the room while the outdoorunit installed

There are 3 types of Split Unit air conditioner :-

Wall type (Lekapan dinding) Cassette type (Lekapan lantai) Ceiling type (Gantungan siling)

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Air Conditioning System Basics andTheories

Most central air conditioning unitsoperate by means of a split system.

1.Hot sideconsist of condensing coil,

compressor & fan located o/sideroom.

2.Cold sideconsist of expansion

valve & cold air (part of furnace/ airhandler) located inside the room.Furnace blow air through evaporatorcoil which cooled the air.DIAGRAM

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The refrigeration cycle:1) condensing coil,2) expansion valve,3) evaporator coil,4) compressor

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Air cond have 5 mechanical components :

i. Compressor

ii. Expansion valve / metering device

iii. Evaporator coil / Condensor

iv. Blower

v. Refrigerant

DIAGRAM

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Fifth level

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Compressor (heart)

Refrigeration cycle uses an electric motor

to drive a compressor.Act as a pump causing the refrigerant to flowthrough the system.

Contain 2 type of feeder : 1. Suction line

2. Discharge line

Its job is to draw in a low pressure, low temprefrigerant in a gaseous state & by compressingthis gas, raise the pressure & temp of therefrigerant.

The high pressure, high temp gas then flows to

the condensor coil.

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Condensor

The condensor coil is a series of piping with a

fan that draws o/side air across the coil.As the refrigerant passes through thecondensor coil & the cooler o/side air passesacross the coil, the air absorbs heat from the

refrigerant which causes the refrigerant tocondense from a gas to a liquid state.

The high pressure, high temp liquid then

reaches the expansion valve.

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Expansion valve (brain) By sensing the temp of the evaporator/

cooling coil,

it allows liquid to pass through a verysmall orifice which causes the refrigerantto expand to a low pressure & low tempgas.

This cold refrigerant flows to the

evaporator.

Evaporator Coil A series of piping connected to a furnace

@ air handler that blows indoor air acrossit causing the coil to absorb heat from theair.

Absorb heat & change refrigerant in liquidstate (low temp/ pressure) to a gas (low

temp/ pressure).

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Operation

A compressor is a pump that compressrefrigerant vapor & pumps the refrigerantthrough the refrigeration system.

The compressed refrigerant moves to thecondensor through the discharge linewhere heat is rejected & the vapor iscondensed into a liquid.

From the condenser the refrigerant ispumped to the metering device where the

amount of the refrigerant moving into theevaporator is controlled.

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The metering device causes part of therefrigerant to vaporize as it moves into the

evaporator & the pressure & temperatureare greatly reduced.

This reduction in pressure causes a severelowering in temp. inside the evaporator.

The evaporator absorbs heat from thesurrounding air which cools the air.

The vapor proceeds through the suction lineto the compressor where it is compressed &the cycle starts over.

S ifi ti

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SpecificationPlaces

RatingDrugstore Beauty Saloon Doctors office

Voltage 208V, 3 , 3 wire,

60Hz

208V, 3 , 3 wire,

60Hz

208V, 3 , 2 wire,

60Hz

Refrigerantcompressor-

motor

Rated load current20.2A, 208V 3

Rated loadcurrent 14.1A,

208V3

Rated loadcurrent 16.8A,

208V3

Evaporator motorFull load current3.2A, 208V 1

Full load current3.3A, 208V

1

Full load current3.7A, 208V

1

Condensermotor

Full load current3.2A, 208V 1

Full load current3.3A, 208V

1

Full load current3.7A, 208V

1

Minimum cctcapacity

31.65A 20.92A 24.7A

Over protection

current

50A, time delay

fuse

35A, time delay

fuse

40A, time delay

fuse

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3-Selit hos akhir untukpenyambung (tertutup) Paip

BahanPaipOksigen

1- Buka penutup yang melindungisambungan oksigen

2-Selit hos akhir untuk penyambung (luar)

Installation & Wiring

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Air Conditioning System Basics and Theories

The refrigeration cycle:

1) condensing coil,2) expansion valve,3) evaporator coil,4) compressor

Heat pump transfers heat from a lower temperature heatsource into a higher temperature heat sink. Heat would

naturally flow in the opposite direction. A refrigerator pumps the heat out of the interior into theroom in which it stands.

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Refrigeration cycle uses an electric motor to drive acompressor.

Since evaporation occurs when heat is absorbed, and

condensation occurs when heat is released, airconditioners are designed to use a compressor tocause pressure changes between two compartments,and actively pump a refrigerant around.

A refrigerant is pumped into the cooled compartment

(the evaporator coil), where the low pressure and loadtemperature cause the refrigerant to evaporate into avapor, taking heat with it.

In the other compartment (the condenser), the

refrigerant vapour is compressed and forced throughanother heat exchange coil, condensing into a liquid,rejecting the heat previously absorbed from the cooledspace.

Refrigerant cycle 1

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Refrigerant cycle 1

Pemampat akan memampatkan wap bahan dingin ygbertekanan/ suhu rendah menjadi wap bahan dingin ygbertekanan/ suhu tinggi & dialirkan ke pemeluwapan melalui

discharge line.

Pemeluwap haba yg disingkirkan lalu wap bahan dingin ygbertekanan/ bersuhu tinggi menjadi cecair bahan dingin ygbertekanan/ bersuhu tinggi & dialirkan ke peranti pemeteranmelalui liquid line.

Peranti pemeteran Cecair bahan pendingin yg bertekanan/bersuhu tinggi akan dikawal pengalirannya lalu menjadi cecairbahan dingin yg bertekanan/ bersuhu rendah & dialirkan kepenyejat melalui evaporator line.

Penyejat Haba diserap lalu cecair bahan dingin ygbertekanan bersuhu rendah menjadi wap bahan dingin ygbertekanan/ suhu rendah & masuk ke pemampat melaluisuction line.

Seterusnya proses ini berulang semula.

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Refrigerant cycle 2

Satu proses mengalihkan haba dari satu

tempat ke tempat yg lain.Haba dialih melalui unit penyejat dandisingkirkan ke udara luar pd unitpemeluwap bg setiap jenis alat pendinginudara.

Dlm proses pemindahan haba, 4 pekara inidiperlukan dlm kitaran tsbt iaitupemeluwap, pemampat, pemejalwapandan injap pengembagan dan menjadibahan pendingin.

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Condensation

(pemeluwap)

Compressor

Evaporation

(penyejat)

Txv ( meter equipment)

Low pressure /

Low Side

High pressure /

High Side

Dust

Refrigerant (Freon 11 Freon 12 Freon 22)

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Refrigerant (Freon-11, Freon-12, Freon-22)

Refrigerant are designated with an R & a number.

The refrigerant must be safe, detectable, have low boiling

point & have good pumping characteristics.Freon - These refrigerants used due to the superiorstability and safety properties. Unfortunately, evidencehas accumulated that these chlorine bearing refrigerantsreach the upper atmosphere when they escape.

CFC refrigerants in common but receeding usage includeR-11 and R-12.

Environmentally-safe refrigerants include HCFCs (R-22,used in homes) & HFCs (R-134a, used in cars) have

replaced CFC use.HCFCs in turn are being phased out under the MontrealProtocol and replaced by hydrofluorocarbons (HFCs),such as R-410A, which lack chlorine.

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D O L

OUTDOOR UNITINDOOR UNIT

L

E

N

C(A)

SR(P)

AC

S

CM

CFM

L

RC

SPEEDCONTROL

RECEIVER POWER SUPPLY

TIMER

TEMPERATURECONTROL

TRANSMITTER

L

LC

E

N

RELAY

MOTORA/C

Indoor Unit

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Indoor UnitPower Supply - Convert AC -> DC

- Step down voltage

- Distribute voltage

Receiver Cct - Receive instruction from user via remote control

Timer - Every line must pass through the timer.

- Timer is for delay

- Setting time for ON/OFF

Speed Control - Instruction in voltage signalRelay - Voltage from speed control send to the relay

- Relay On, voltage supply enter & start themotor.

Negative Thermistor (NTC)

positioned at the evaporator inlet side. - NTC Temp. low , resistance increase (cold)

- PTC Temp. high, resistance increase (hot)

- suitable temp. in Malaysia 21C humidity 55%

Outdoor Unit

Overload Relay - When overload occurred, relay will open.

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Direct On Line (D.O.L.)Function For overload protection.

Load below 7.46W / 1Hp no need to use DOLFuse to open when O/L occur

Thermal O/L Relay (TOR) Trip when thermal notnormal condition

PB start To start the cct.

PB Stop To stop the cct.

When push PB start button, Motor Contactor (MC) will beNormally Close, motor coil will get the power supply andthe Motor will operate.

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Third level Fourth level

Fifth level

Direct On Line (D.O.L.)

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Third level Fourth level

Fifth level

Control circuit for Star - Delta

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Star - Delta Power Circuit

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Star - Delta Connection

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Star Delta Cct operation

Power cct for motor operation need Star - Delta cctto get a smooth start.

To start the motor, the torque power need to be high.

So, for starting time, its use Star cct because whenthe magnet flux is high, the power torque high.

The connection to Star cct is in 3 ~ 5 sec.

Then after 5 sec @ the motor operate, the Delta cctwill operate for motor running time.

This type of connection is used to operates loadbelow 5 Hp ~ 20 Hp.

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Notes : Operate load between 20 Hp ~ 100 Hp

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Maintenance & TroubleshootingThe system has an effect on the amount of energy

that is used & the amount of money that is spent eachmonth.

Air cond also have influence to an individual throughthe air quality.

Nowadays, split unit system is the most popular type that are

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Nowadays, split unit system is the most popular type that arechoose by the customer.

Besaide it is operating quietly, it is also built in with an optionalfunction like the ironnizer. There is 4 maintenance task that need

to be implement to makesure the airconditioner operates followthe specification.

1. Filter cleaning Filter is take out from the cover and clean byusing water. Dry the filter before assemble it again.

2. Evaporater cleaning Clean the evaporator (cooling coil)from dust by using vacuum.

3. Water duct cleaning Clean the water duct that feed waterout from evaporator to avoid water jelly by using air blower.

4.

Condensor checking Makesure the aluminium fin is notblock with the area that is near to each other.

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An air conditioning system should be checked twiceeach year by a qualified person. An inspection typicallyincludes :

1. Checking system functions & safety controls &adjusting the operating sequence where appropriate.

2. Make an inspection to an electrical components &connections & repairing/ replacing @ tightening asrequired. i.e checking the contactor, check capacitor.

3. Ensuring proper airflow & changing dirty air filters.

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4. Inspecting pumps & checking flow rates whereappropriate.

5. Cleaning & lubricating motors are required.

6. Examining belts, and adjusting & aligning asrequired.

7. Inspecting, cleaning & balancing blowers asrequired.

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Maintenance Record (Maintenance schedule for 25 to 50hours or months)

This schedule consist of checking method that need to

be done in every 25 to 50 hours or per month to any air

conditioner. The process that will be implement and

record in the monthly schedule is :-

Refill the gaseous and check the gas pressure.

Check the blower ( Fan )

Check the cool water and makesure it is a pure water

B l h d l h th l f i t h d l f 25

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Subject Date Type of failure Action taken

1 Gas/

Refrigerant

30.1.2007 Air not cool Check refrigerant pressure

Add refrigerant gas if itsbelow requirement level

2 Cooling tower 30.1.2007 Water coolen lessTower dirty

Check water coolant( added when lesser water

coolant). Clean reservoir3m/6m. Replace with watermixed with chlorine.

3 Blower (Fan) 30.1.2007 Fan dirtyRotation of the fan istoo rigorousThe filter is dirty

Clean the fan from dust. Grisshould be done.Clean filter.

4 Cooled Water 30.1.2007 Water mixed a lotwith impurety

Need the water pure.

Below schedule show the example of maintenance schedule for 25to 50 hours or permonth.

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Institute of Electrical Engineering (IEE)Laws

Always wear googles when working with refrigerant in these

systems. Always wear googles around ductwork to prevent cutting the

hands and fingers. Provide protective shields around operating motor & fans.

Be sure that the electric power is off before servicing

electrical components. Keep hand, feet & clothing clears of belts, fans & ratating

parts. Use only safe ladders when working on the roofs of building.

Never carry equipment , tools @ supplies up @ down aladder. Transport these items with a rope of buildings.

Avoid contact with electric circuits when the area around theequipment is wet.

Unit should firmly fixed at a place that have a set that

endurable to carry heavy thing.

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3-Selit hos akhir untukpenyambung

(tertutup) Paip

BahanPaipOksigen

1- Buka penutup yangmelindungi sambungan

oksigen2-Selit hos akhir

untuk penyambung(luar)

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Assignment 2

1. Explain the method of operation for each type of

below unitary system & give 3 advantages and

disadvantages for each unit type :

a. Window unit

b. Remote Split System Lekapan dinding

c. Remote Split System Lekapan lantai

d. Remote Split System Lekapan ceiling

e. Self Contained System - Water-cooled systems

f. Self Contained System - Air-cooled systems

g. Packed Units - Water Cooled

h. Packed Units - Air Cooled

2. Give 3 IEE Regulation that relates to air cond system.