Installing domestic refrigeration and air-conditioning (Domrac) units

WEB SCRIPT HEATING, VENTILATING, AIR-CONDITIONING AND REFRIGERATION
Sector: (HVAC/R)
Qualification: RAC Servicing NC II
Unit of Competency:
Module Title: Install Domestic Refrigeration And Air-Conditioning (Domrac) Units

Learning Outcomes: Installing Domestic Refrigeration And Air-Conditioning (Domrac) Units
1. Conduct survey
Developer/s: 2. Install DomRAC Electrical Circuit
3. Install Domrac Unit
4. Conduct Performance Test
Angelito Nelson G. Mendoza

TITLE INSTALLING DOMESTIC REFRIGERATION AND AIR-CONDITIONING
OBJECTIVES (DOMRAC) UNITS
At the end of this unit, you should be able to:
INTRODUCTION 1. Conduct survey
LEARNING OUTCOME 1 2. Install DomRAC Electrical Circuit
3. Install Domrac Unit
4. Conduct Performance Test
This module covers the knowledge, skills and attitudes required to safely install
and test domestic refrigeration and air-conditioning (DomRAC) units. It includes
conducting survey for installation, installing DomRAC unit and its electrical
circuit as well as conducting performance testing.

CONDUCT SURVEY

TOPIC 1 In this lesson, you will learn to Assess Site Conditions

SITE ASSESSMENT

Selecting an Area for Installation:
 In selecting an area for installation, the following should be avoided to

prevent damage or harmful effect to the unit:
 Greasy areas (e.g. areas near a machine)
 Salty areas (e.g. places/areas near the coast )
 Areas where sulphuric gas is present ( such as hot spring areas)
 Areas near flammable gas (e. g. LPG)

Greasy area Salty Area

Sulphuric Gas Flammable

It is important that the location selected where the unit will be placed suits the
customer’s needs.

Side View Top View

ACTIVITY  Inter active activity using H5P Activity no. 1:Read Information sheet 1.1-1:
LEARNING OUTCOME 2 Operation of Window-type Air-conditioning Unit

 Inter active activity using H5P Activity no. 2: Answer Self-check 1.1-1 Test
what you have learned about the basic operation of window-type air-
conditioning

 Inter active activity using H5P Activity no. 3: Read Information sheet 1.1- 2
Selecting an area for installation

 Inter active activity using H5P Activity no. 4: Answer Self-check 1.1-2 Test
what you have learned about the selecting area for installation of window
type air-conditioning unit

INSTALL DOMRAC ELECTRICAL CIRCUIT

TOPIC 1 ROUGHING-IN ACTIVITIES

Perform Cavity Works
• Laying out or marking the location of air-con to be installed is the
process of transferring the data from the installation plan or working drawing
into the wall where the unit will be installed. The purpose of this is to eliminate
the risk of committing error while cutting through the wall.

Measure Height Measure Width Record the Data

Select Appropriate Execute Layout Finalize the Job
Location

Roughing-in activities of electrical installation deal with marking-out locations of
electrical components, mounting of electrical boxes, raceways and metal circuit
protection enclosures. Here are the steps considered in these activities.

Working Drawing Mounting of Safety
Switch and Devices

ACTIVITY 2  Inter active activity using H5P Activity no. 6: Perform Job sheet 1.2-1a
TOPIC 2 Laying Out Cavity Dimension of an Air conditioning

 Inter active activity using H5P Activity 7: Perform Job sheet no. 1.2.1b
Performing single outlet electrical installation for window type air-
conditioning

Electrical Cabling And Wiring Devices

Electrical cable is an assembly of one or more wires running side by side or
bundled, which is used to carry electric current. While wire is a single electrical
conductor.

Size of wire Types of wire Ampacity

HP Rating Overcurrent Safety Switch
Protection Enclosures

ACTIVITY  Inter active activity using H5P Activity no. 8: Read information sheet 1.2-2.a
Selecting electrical conductors for installation

TOPIC 3  Inter active activity using H5P Activity no. 9: Assignment sheet no. 2: Select
conductors for various ampacities and temperatures

 Inter active activity using H5P Activity no. 10: Assignment sheet no. 3:
Select conductors for given horsepower rating of the load

 Inter active activity using H5P Activity no. 11: Read information 1.2-2b: Over
current protection

 Inter active activity using H5P Activity 12: Quiz- Matching type- Over current
protection

 Inter active activity using H5P Activity no. 13: Read information sheet 1.2-2c
Load center and safety switch enclosures

 Inter active activity using H5P Activity 14: Answer Self-check no. 1.2-2
Identify Enclosures and symbols

ELECTRICAL CIRCUIT

It is important to test first the unit in accordance with applicable PEC provisions
before installing it on to the wall permanently. This will help you ensure that the
unit is in good condition. Doing so will also save you time, energy and
resources.
 Imagine yourself installing the unit without testing first and pulling it out from

the cavity because it is found defective.

ACTIVITY Below are the steps in testing the electrical circuit of the unit.

 Check the resistance of the unit using the multitester.
 Low
 Med
 High

 Watch video presentation no. 1 on A/C Fan Motor Check & Tester Low,

Med, High and Cool

 Inter active activity using H5P Activity 15: Assignment no. 4: Record the

resistance of your electric fan

LEARNING OUTCOME 3 INSTALL DOMRAC UNIT

TOPIC 1 BODY PARTS AND COMPONENTS

Before installing the air-conditioning unit, preliminary inspections should be
done to ensure that the unit‘s parts are complete, its body is in good condition
and the unit is in good operational condition.

Basically, the air-conditioning unit package has the following parts:

Air-conditioning unit Front panel

Air-filter Housing

Brand new units have the basic components and some of the following:

Foam Brackets Screws

Drain pan Remote control

For brand new units, you need to inspect whether the unit‘s parts are complete.
You may do this by comparing the actual parts by what is listed in the manual.
You should check for paint for scratches or *dents in the body and/or housing. If
there are some defects found in the unit or lacking of parts, it is important to
inform your local distributor to avail warranty services. They will be happy to
help you because its part of their service.

For used units, you need to check the base plate of the unit for defects or
corrosion. Defective or corroded base plate may cause misalignment of the
mechanical parts of the air-con (usually the fan blade) when installed and
operated. It may also reduce the lifespan of the unit if not remedied.

Corroded
base plate

ACTIVITY  Inter active activity using H5P Activity 16 Read information sheet no 1.3.1
Pre-inspection of Window-type Air-conditioning UnitInter active activity using
H5P

 Inter active activity using H5P Activity 17: Answer Self-check 1.3.1 on Test
what you have learned about the pre-inspecting air-conditioning unit before

TOPIC 2 installation

ACTIVITY BRACKET, HANGERS, FRAMES AND UNIT POSITION
TOPIC 3
Make sure that the brackets are installed and Unit is positioned and levelled in
ACTIVITY accordance with manufacturer’s recommendation and/or RAC Code of Practice
TOPIC 4
Here are some steps and instruction to be followed:
ACTIVITY  Mark the locations of the holes to be drilled
TOPIC 5  Use the hole of the housing as reference
 Mount the housing least 12 mm (or as stated in the air-con manual)

extension away from the surface of the wall
Install steel brackets tilt to the back one-fourth inch (1/4”) to allow the moisture
runs to the back where it should drain to the outside

Watch video presentation no. 2 on Window AC Bracket Installation

RAC SEALING MATERIALS

Sealing materials are installed to ensure an air tight seal around the unit in line
with manufacturer's instructions and/or RAC Code of Practice.
 Slide the unit into the housing until it is firmly against the rear of the housing.

Care is required to ensure the foam sealing strips on the housing remain in
position. Ask help for this step.
Note: DO NOT ATTEMPT TO LIFT THE UNIT ALONE!
 Fit the front panel to the unit and make sure that it is securely mounted (see
unit’s manual).
Seal gaps between housing and casing by using rubber, foam, plastic, silicone.
This is to ensure that the unit is air-tight.

Watch video presentation no. 3 on How to Seal an Air Conditioner Window Gap

CONDENSATE DRAIN
Condensate drain is installed in accordance with manufacturer’s
recommendation and/or RAC Code of Practice.
 Fit the drain chute to the housing and run a drain line to a suitable location if

required.
Note: Some units may have a permanent drain pipe attached to the chassis.
 Cut a length of old garden hose or a piece of washer hose.
 Insert a screw-band hose clamp over one end of the length of hose.
Watch video presentation no. 4 on Air Conditioner (window A/C) Drain
Condensation Drip Catcher to Garden Hose Connector

SAFE MANUAL HANDLING TECHNIQUES

Safe manual handling techniques are employed in line with enterprise OH&S
procedures.
 When carrying, keep the load close to your waist for as long as possible.

Put the heaviest side of the load closest to your body. Keep your head up
and look ahead, not down at the load, and avoid twisting or leaning
sideways. If you need to, put the load down and adjust your grip before
continuing the lift.
 Moving and handling, also known as ‘manual handling’, is any action
involving physical effort to move or support an object or person by:

ACTIVITY  Lifting
LEARNING OUTCOME 4  Pushing
 Pulling
 Manoeuvring
 Steadying
 Carrying
 Transporting

By law, and by OH&S procedures, employers are required to undertake a risk
assessment and do everything that is reasonably practicable in order to reduce
the risks associated with manual handling. Amongst other actions, this includes
introducing control measures to ensure workers understand how to lift, push
and pull correctly, using mechanical aids where available and reducing the
need for manual handling altogether.
Watch video presentation no. 5 on Manual Handling and basic steps to correct

lifting technique

CONDUCT PERFORMANCE TEST

TOPIC 1 VOLTAGE AND CURRENT
Voltage and current are measured according to unit power requirements.

ACTIVITY  Check the supply requirement of the unit (see attach name plate of the unit)
TOPIC 2  The source line for the unit should be the same or within the tolerable limit

of the supply requirement. In the Philippines, our source line is 220 volts 60
Hz; before using the unit for this supply, check if it is for 220 volts 60 Hz
 Connect clamp tester on one line of the service cord in order to measure the
current drawn by the unit both in fan mode and cooling mode.
 Connect the air conditioner in the power
 Switch the unit on the fan mode and record the current reading (in amperes)
 Turn the unit on cool mode and record the current reading (in amperes)
 Measure the current and then refers to nameplate F.L.A.
Note:
 Do corrective action in case the power is not suited for the unit.
In case the source is greater than the required supply, step-down transformers
should be used to reduce the source line.
 Watch video presentation no. 6 on Perform a Voltage Check on a 240 Volt
Outlet
 Watch video presentation no 7 on How-To use a clamp-on ammeter

AIR TEMPERATURE AND VELOCITY

 Set the air-con unit on the floor or any flat base

 Manually rotate the fan blade of the unit while on the floor or flat base to
make sure that the blade would rotate smoothly.

 Switch-on the unit into fan mode, Observe if the fan blade would rotate
smoothly.

 Wait for about 5 minutes then try switching the unit into low cool.
 Feel the outlet of air for change in temperature (from warm air to slightly

cold air).
 If there is a change in temperature, the unit is working properly.

Set the air-con unit Manually rotate the
on the floor or any fan blade
flat base

Switch-on the unit into Switch-on the unit into
fan mode cool mode

ACTIVITY  Inter active activity using H5P Activity 18: Answer multiple choice question-
TOPIC 3 Checking Air Temperature and velocity

SOUNDS AND VIBRATION

Sounds and vibration are checked based on unit;
 Observe the fan blade if it would rotate smoothly.

 Sluggish or screeching sound will be heard on the unit if the blade
movement is restricted.

 After switching the unit into low cool. You will be hearing another sound,
which only indicates that the compressor motor is now running.

If the unit is working properly, the unit can now be switched-off and unplugged.
It is now ready to be installed

Observe the fan blade if it Switch to low cool
would rotate smoothly

ACTIVITY  Inter active activity using H5P Activity no. 19: Answer true or false quiz-
Checking Sounds and vibration

TOPIC 4 SERVICE REPORT

Job documentation or Service report is accomplished in line with enterprise
policies and procedures.
The documentation process in a company may vary from one form to another.
The most common is the Service Report or sometimes called:
 Pre-Inspection form

 This checklist is to ensure the unit is in good running condition before
installing to the cavity

 Job Order Form
In this part of the service record, you tick on the type of service you rendered to
the costumer.

Pre-Inspection Report Job Order Form

ACTIVITY  Inter active activity using H5P Activity no. 20: Accomplish Worksheet 1.4-1a
on Checklist for Pre-inspection of Window-type Air-conditioning Unit

 Inter active activity using H5P Activity no.21: Accomplish Worksheet 1.4-1b
for Assignment in Installing Window-type Air-conditioning Unit