Module 5 Install dom RAC Units PDF

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COURSE MODULECOURSE CODE: RACModule 5 2 nd Semester, S. 2020-IntroductionThis module covers the knowledge, skills and attitudes required to safely install andtest domestic refrigeration and air-conditioning (DomRAC) units. It includesconducting survey for installation, installing DomRAC unit and its...

Description

COURSE CODE: RAC Module 5 2nd Semester, S.Y. 2020-2021

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Introduction 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.

Intended Learning Outcomes 

Install domestic refrigeration and air-conditioning (DomRAC) units

CONDUCT SURVEY (Assessment on Site Condition) Identify Air Circulation/Ventilation Requirements 2013 Building Energy Efficiency Standards – Reference - Ventilation Requirements

All of the ventilation requirements are mandatory measures. Some measures require acceptance testing. Within a building, all enclosed spaces that are normally used by humans must be continuously ventilated during occupied hours with outdoor air, using either natural or mechanical ventilation (a)1 An exception is provided to (a)1 for refrigerated warehouses or other buildings or spaces that are not normally used for human occupancy or work. The standards allow for ventilation to use transfer air as long as it doesn’t have any “unusual sources of indoor air contaminants” and “the outdoor air that is supplied to all spaces combined, is sufficient to meet the requirements for each space individually. Good practice dictates that sources of contaminants be isolated and controlled with local exhaust. The designation and treatment of such spaces is subject to the designer’s discretion. Spaces needing special consideration include:

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Spaces normally used by humans” refers to spaces where people can be reasonably expected to remain for an extended period of time. Spaces where occupancy will be brief and intermittent, and that do not have any unusual sources of air contaminants, do not need to be directly ventilated. For example: •A closet does not need to be ventilated, provided it is not normally occupied. •A storeroom that is only infrequently or briefly occupied does not require ventilation. However, a storeroom that can be expected to be occupied for extended periods for clean-up or inventory must be ventilated, preferably with systems controlled by a local switch so that the ventilation system operates only when the space is occupied. “Continuously ventilated during occupied hours” implies that the design ventilation must be provided throughout the entire occupied period. This means that VAV systems must provide the code-required ventilation over their full range of operating supply airflow. Some means of dynamically controlling the minimum ventilation air must be provided.

Structural And Architectural Requirement

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Installation Guidelines

The air conditioner should be braced from underneath with metal brackets, mounting rails, or similar supports, or firmly fastened from inside with supporting angles. The metal brackets and angles should be attached to the exterior of the building and be strong enough to support the size and weight of the unit. Anything used to adjust the position of the air conditioner, such as shims, should be independently secured to prevent shifting caused by vibration, wind, or typhoon. The air conditioner should remain in place when the window is opened, or secured so that the window cannot be opened accidentally. Tilting the unit for drainage is OK as long as it isn't at a steep angle. Dangers come not only from an improperly secured air conditioner itself, but also from any loose objects used to support it. Bricks, wooden blocks, phone books, or (in one case we've seen) video cassette tapes should never be wedged between an air conditioner and the window sill. Items such as flower pots, satellite dishes, and bird feeders should not be placed on top of the unit, either. Aside from these general guidelines, there are factors specific to each installation that should be considered, such as the size and weight of the air conditioner, the width of the window, the depth of the windowsill, the condition of the window frame, whether the unit is installed on the top or at the bottom of the window opening, and how much of the air conditioner extends outside the window.

Assess Site Condition Air conditioners have circulation systems designed to project cool air away from the units while refrigeration units have circulation systems designed to retain coolant in a confined space. Refrigeration systems circulate cool liquids and gases through a series of tubes and vents.

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Power Supply Requirements Power Requirements Each system, when properly configured and installed, must receive sufficient incoming AC power to supply all installed components. The data center should be able to provide a stable, dual-current path to the installed equipment. In addition,

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the power infrastructure must be designed to maintain system uptime even during disruption of the main power source. It is important to use dedicated AC breaker panels for all power circuits that supply power to your systems. The power system should be designed to provide sufficient redundancy, eliminate all single points of failure, and allow the isolation of a single system for testing or maintenance without affecting the power supplied to other systems.

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Drain Disposal Requirements

Indirect Waste Connections Condensate from air cooling coils and the overflow from evaporative coolers and similar water supplied equipment shall be collected and discharged to an approved plumbing fixture or approved disposal area. A.

An approved plumbing fixture for the purposes of this section shall be:

1.

An approved trapped and vented receptor connected to a sanitary sewer.

2.

A downspout that terminates in an approved disposal area.

B.

An approved disposal area for the purposes of this section shall be:

1.

A dry well with a rock fill 12” x 36” Deep

2.

A planted area large enough to accept the discharge waste.

3.

A storm drains system.

Installation of Condensate Piping. The installation of condensate piping shall be as follows: 1. Slope - The drain shall have a slope of not less than 1/8 inch per foot and shall be approved corrosion resistant pipe not less in size than 3/4 of an inch for air cooling coils and not less than the drain outlet size for evaporative coolers or other equipment. 2. Public Way - Condensate or wastewater shall not drain over a public way. For the purpose of this section, public way shall include sidewalks and driveways. 3. Materials (pipe) - Approved corrosion resistant pipe for the purpose of the section shall be: ABS-DWV, cast iron, Durham Systems, hard drawn copper, PVC-DWV, and Schedule 40 PVC plastic piping. 4. Materials (fittings) - Short pattern 90-degree ells are prohibited. Use only recess pattern fittings. Drainage pattern fittings are required for piping 1 1/4 inches or larger.

5. Traps - A trap shall be installed in the condensate line at the evaporator unit when required by the manufacturer’s installation instructions.

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6. Cleanouts - The installation and location of cleanouts in condensate drain lines shall conform to the manufacturer’s installation instructions. In the absence of such specifications in the installation instructions, an accessible cleanout shall be required at the unit. Plugged tees, union connections, or short clamped hose sections at the unit are all acceptable cleanouts. Main condensate piping receiving condensate waste from more than one evaporator outlet shall be provided with an accessible cleanout at each change of direction. 7. Hangars and Supports - All condensate piping shall be supported so as to maintain a straight alignment, a uniform slope, and intervals required by the Uniform Plumbing Code. 8. Thermal Expansion - Allow for thermal expansion and movement in all plastic piping installations by the use of approved methods. Support, but do not rigidly restrain, piping at branches or changes of direction. Do not anchor rigidly in walls. Holes through framing members shall be adequately sized to allow free movement. 9. Protection from Damage - Plastic piping passing through wood studs or plates shall be protected from puncture by a minimum 1/16-inch thick steel plate. All plastic piping shall be protected from concrete form oil, direct sunlight, and mechanical damage. 10. Piping Size - Pipe size shall be as shown in the following table: Equipment Capacity Minimum Up to 20 tons of refrigeration 21 to 40 tons of refrigeration 41 to 90 tons of refrigeration 91 to 125 tons of refrigeration 126 to 250 tons of refrigeration Size of condensate drains may be for recommended by the manufacturer.

Condensate Drain Diameter 3/4 inch 1 inch 1 ¼ inch 1 ½ inch 2 inches one unit or a combination of units or as

Secondary Condensate Control Additional condensate control is required when a cooling coil or cooling unit is located in an attic or furred space where damage may result from condensate overflow. This control shall be provided by an additional watertight pan of corrosion resistant metal installed under the cooling coil or unit to catch overflow condensate due to a clogged primary condensate drain. One pan with a standing overflow and a separate condensate drain may be used in lieu of the secondary drain pan. The additional pan or the standing overflow shall be provided with a drainpipe, 3/4-inch minimum pipe size, discharging at a point that can be readily observed.

Provision For Serviceability Selecting the Location for Installation In selecting the location for installation, the aspects of efficiency, economy and good practice should be considered and wherever possible it shall be made contiguous with the building. This room shall be located as centrally as possible with respect to the area to be air conditioned and shall be free from obstructing columns.

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2.9.1.5 Equipment Installation a) General: Mechanical equipment and appliances shall be installed in accordance with the manufacturer's installation instructions for the labeled equipment. Connections to mechanical equipment or appliances, such as fuel supply, electrical, hydronic piping, vent and ducts shall conform to the requirements of this Code. b) Clearance: Appliances shall be installed with the minimum clearances to combustibles for which the appliance has been tested as specified by the manufacturer. c) Anchorage of Appliances: Appliances designed to be fixed in position shall be securely fastened in position. Supports for appliances shall be designed and constructed to sustain vertical and horizontal loads within the stress limitations specified in the Building Code. d) Noise and Vibration: Equipment noise and vibration transmitted to the occupied space shall not exceed the recommended value for the space. Selection and installation of equipment shall be in accordance with Sec 2.4.3. e) Identification of Equipment: When more than one air ‐conditioning, heating, refrigerating or ventilation systems are installed on the roof of a building or within the building, each equipment shall be identified as to the area or space served by the equipment. 2.9.1.6 Access All mechanical equipment and appliances shall be accessible for inspection, service, repair and replacement without removing permanent construction. Unless otherwise specified not less than 750 mm of working space and platform shall be provided to service the equipment or appliance. Appliance controls, gauges, filters, blowers, motors and burners shall be accessible. The operating instructions shall be clearly displayed near the appliance where they can be read easily.

2.9.1.7 Location

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a) Remote Location: Where an appliance is located in a remote location, a walkway having a minimum width of 600 mm shall be provided, leading from the access opening to the appliance. b) Hazardous Location: Appliances installed in garages, warehouses, or other areas where they may be subject to mechanical damage shall be installed behind suitable protective barriers or at a suitable height above the floor or located out of the normal path of vehicles to guard against such damages. Air‐conditioning or heating equipment located in a garage and which generates a glow, spark or flame capable of igniting flammable vapours shall be installed in such a way that the pilots and burners or heating elements and switches are at least 450 mm above the floor level. Where such appliances installed within a garage are enclosed in a separate approved compartment having access only from outside of the garage such appliances may be installed at floor level, provided the required combustion air is taken from and discharged to the exterior of the garage. Heating equipment located in rooms where cellulose nitrate plastic or other explosive materials are stored or processed shall comply with the requirements of Part 4: Fire Protection. c) Outdoor Installation: Mechanical equipment and appliance located outdoors shall be approved for outdoor installation. Mechanical equipment and appliances installed outdoors shall conform to the requirements of Sec 2.6.1.5. Where appliances are located within 3 m of a roof edge or open side of a drop greater than 600 mm, guards shall be provided. Height of the guard shall be a minimum of 900 mm and a maximum of 1050 mm above the surface. Equipment that are located outdoors and may be adversely affected by sun and/or water shall be adequately protected. Access shall be possible under all weather conditions. All outdoor installed equipment shall be so located that the sound level shall not be more than 65 dB when measured anywhere on the property boundary line.

2.9.1.8 Electrical Installations a) Equipment regulated by this code requiring electrical connections of more than 50 volts shall have a positive means of disconnect adjacent to and in sight from the equipment served. A 230 volt AC grounding type receptacle shall be located within 8 m of the equipment for service and maintenance purposes. The receptacle need not be located on the same level as the equipment. Low voltage wiring of 50 volts or less within a structure shall be installed in a manner to prevent physical damage.

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b) Permanent lighting shall be provided to illuminate the area in which an appliance is located. For remote locations, the light switch shall be located near the access opening leading to the appliance. Exceptions: Lighting fixtures need not be installed when the fixed lighting for the building will provide sufficient light for safe servicing of the equipment. 2.9.1.9 Condensate Wastes Condensates from air cooling coils, fuel burning condensing appliances and the overflow from evaporative coolers and similar water supplied equipment shall be collected and discharged to an approved plumbing fixture and disposal area. The waste pipe shall have a slope of not less than 1 in 100 and shall be of approved corrosion resistant material and approved size. Condensate or waste water shall not drain over a public way. 2.9.1.10 Personnel Protection A suitable and substantial metal guard shall be provided around exposed flywheels, fans, pulleys, belts and moving machinery which are portions of air‐conditioning, heating and ventilation system. Equipment Space Requirements of space for erection and installation of air‐ conditioning, heating and ventilation system equipment and machinery (ducting, cooling, heating and air‐conditioning equipment; refrigerating machinery, boiler etc.) shall be determined during the planning stage of the building so that it can be incorporated in the building planning effectively. Requirements of equipment/machinery space shall be determined taking consideration of actual equipment and machinery space; clearance space for operation; maintenance and fire prevention requirement; access space and other requirements of this Code. Building plan shall also include adequate provisions for transportation of equipment and machinery to and from equipment/machinery room, installation of outdoor air inlets and exhaust air outlets. Planning for equipment space shall take into consideration of different parameters described in section 2.5 and 2.6.

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Accomplish Survey Installation Report

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Air conditioner inspection checklist Air conditioners are primary requirements of the organization at offices, chemical storage units, electrical control rooms, computer server rooms etc. , now days the requirement of air conditioners to run the air conditioners are twenty four hours, due to high running frequency that need to take care timely. In case of the air conditioners are failures to serve, possible that some chemicals can reduce its productivities so it’s making big trouble at the movement of manufacturing / processing requirements. Management are takes care of the air conditioners for the checking frequency, responsibility are declare as priority of the requirements, here some sample question for the air conditioners checking points are given below:               

Unit should be clean & dust free, in side as well as outside of the Air conditioner General condition of the unit Unit number, Serial number, identification numbers clearly and legibly. Check whether excessive noise by unit Check whether excessive vibration by unit Condensate directed away from unit Air conditioner at safe position & location? Whether deployed Cover or guards in at place? Screws, nuts and bolts in place Plug, wiring and cables safe in good condition Filter should be clean and without any damage Compressor of the Air conditioner is working properly? Is there extra noise? Unexpectable behaviour noted? Thermostat functioning Controls & switches in working condition Is there any evidence found of gas leakage?

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INSTALL DomRAC ELECTRICAL CIRCUIT

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Performing Single Outlet Electrical Installation Roughing-in activities of electrical installation Materials, Tools and Equipment

Materials Qty. Tools Qty. Equipment Pencil or Pen or 1pc Pull and push 1pc Electric drill chalk rule or any measuring device suited for the activity Installation plan1pc Steel meter 1pc or working stick/Straight drawing edge Flat head 15pcs screw, ¾ in X 10 Fisher, # 6 15pcs (Tox) Plastic molding 2pcs ¾ in X 8 ft. Surface metal 1pc box Mica tube, ¼ 1m in. dia Stranded wire, 20m 2.0 mm2 TW ACU outlet, 3 1pc prong Safety switch, 1pc 30 A

Qty. PPE 1unit Safety glass

QTY. 1pc

Gloves

1pair

Safety shoes

1pair

Roughing-in activities of electrical installation

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Procedure: Roughing-in activities of electrical installation deal with marking-out locations of electrical components, mounting of electrical boxes, raceways and metal circuit protection enclosures.

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OVER CURRENT PROTECTION

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Types of Over Current Protection Types of Fuse What is a Fuse? A Fuse or an Electric Fuse is an Electrical / Electronic device that protects the circuit from different electrical faults like over current and overload. Fuses can be considered as a sacrificial element in the circuit as they act as a weak link in the entire circuit. This is because, a fuse scarifies itself and reliably opens the circuit when there is an excessive current in the circuit or the circuit is under over load and if there is any short circuit. The principle of a fuse is based on the heating effect of the electric current. A simple fuse consists of a small conductive materia...