Repair and Maintenance of Window and Split AC

96 Shri Technologies 2- Indoor unit: The most common type of the indoor unit is the wall mounted type though other types like ceiling mount- ed and floor mounted are also used. The indoor unit produces the cooling effect inside the room or the of- fice and houses the following components:  The evaporator coil or the cooling coil,  Cooling Fan or Blower,  The drain pipe,  Louvers or Fins,  Air filter,  Controls. The power flow in Branch circuit of a Typical split air conditioning unit The split air conditioning units are fed from either:  Single phase power source (see Fig.9 and Fig.11), so its branch circuit and its main power cord consist- ing of 3 wires (The ground wire, hot wire and neutral wire). Or  Three phase power source (see Fig.12), so its branch circuit and its main power cord consisting of 5 wires (The ground wire, 3 hot wires and neutral wire).Shri Technologies

Repair & Maintenance of Window & Split AC97 Shri Technologies

98 Shri Technologies  The branch circuit will originate from one of the single pole/three pole Overcurrent protective device OCPD included in an electrical panel.  Then go through raceway system (conduits, ducts, …) to a disconnect means of some type suitable for the application.  After that, the main power cord of the split air conditioning unit is connected to this disconnecting means from one side, the other side is connected to the terminal box in the indoor unit (see Fig.9) or in the outdoor unit (see Fig.10)according to the manufacturer’s recommendations and wiring diagrams. Note: if power source connections made in indoor unit, an indoor disconnecting means is used and if power source connections made in outdoor unit, an outdoor disconnecting means (see Fig.14) with suitable iden- tity of protection (IP) is used (review the manufacturer’s recommendations and wiring diagrams).Shri Technologies

99 Finally, the power is transferred via 3-wire cable or 5-wire cable from the terminal box in indoor unit to the terminal box in outdoor unit or vice versa as indicated in the above point. Note: There is a signal cable also connecting the control in the indoor unit with the control in the outdoor unit. 2.3 Electrical wiring connections inside The Split air conditioning units The electrical wiring inside both of indoor and outdoor units is more complicated than that of window air conditioning units. It is always factory wiring and from our point of view as electrical power engineers, it will not affect our work at all. However, we provide some examples for the electrical wiring diagrams in- cluding control wiring for reference as in below Fig.Shri Technologies Repair & Maintenance of Window & Split AC

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Repair & Maintenance of Window & Split AC101 Shri Technologies

102 Shri TechnologiesShri Technologies Over current (load) protector, Thermal fuse, Cooling fan Over Current (load) Protector: The fundamental purpose of overcurrent protection is to protect conduc- tors and equipment against the effects of excessive temperature on conductors and conductor insulation from overcurrent. An overcurrent exists when current exceeds the rating of conductors or equipment. It can result from overload, short circuit, or ground fault. An overload is a condition in which equipment or conductors carry current exceeding their rated ampaci- ty. An example is plugging two 12.5A (1,500W) hair dryers into a 20A branch circuit. A short circuit is the unintentional electrical connection between any two normally current-carrying con- ductors of a circuit (line-to-line or line-to-neutral). A ground fault is an unintentional, electrically conducting connection between an ungrounded conductor of a circuit and the equipment grounding conductor, metallic enclosures, metallic raceways, metallic equipment, or earth. During a ground fault, dangerous voltages and abnormally large currents exist. Circuits or equipment? OCPDs protect circuits and equipment, but they protect circuits in one way and equipment in another. An OCPD protects a circuit by opening when current reaches a value that would cause an excessive tem- perature rise in the conductors. Using a water analogy, current rises like water in a tank — at a certain lev- el, the OCPD shuts off the faucet. Think in terms of normal operating conditions that just get too far out of normal range. The interrupting rating must be sufficient for the maximum possible fault current available on the line-side terminals of the equipment [110.9]. You'll find the standard ratings for fuses and fixed-trip circuit breakers in 240.6. An OCPD protects equipment by opening when it detects a short circuit or ground fault. Every piece of electrical equipment must have a short-circuit current rating that permits the OCPDs (for that equipment) to clear short circuits or ground faults without extensive damage to the electrical components of the cir- cuit [110.10]. Short circuits and faults aren't normal operating conditions. Thus, the OCPDs for equipment have different characteristics than OCPDs for conductors.

103 Thermal fuse: The fuses to be considered are current sensitive devices designed to serve as the intentional weak link in the electrical circuit. Their function is to provide protection of discrete components, or of complete circuits, by reliably melting under current overload conditions. The first fuses were simple, open-wire devices, followed in the 1890’s by Edison’s enclosure of thin wire in a lamp base to make the first plug fuse. By 1904, Underwriters Laboratories had established size and rating specifications to meet safety standards. The renewable type fus- es and automotive fuses appeared in 1914, and in 1927 Littelfuse started making very low amperage fuses for the budding electronics industry The fuse sizes in following chart began with the early “Automobile Glass” fuses, thus the term “AG”. The numbers were applied chronologically as different manufacturers started making a new size: “3AG,” for example, was the third size placed on the market. Other non-glass fuse sizes and constructions were determined by functional requirements, but they still retained the length or diameter dimensions of the glass fuses. Their designation was modified to AB in place of AG, indicating that the outer tube was constructed from Bakelite, fibre, ceramic, or a similar material other than glass. The largest size fuse shown in the chart is the 5AG, or “MIDGET,” a name adopted from its use by the electrical industry and the National Electrical Code range which normally recognizes fuses of 9/16”× 2” as the smallest standard fuse in useShri Technologies Cooling fan: A mechanical fan is a machine used to create flow within a fluid, typically a gas such as air.[1] Repair & Maintenance of Window & Split AC The fan consists of a rotating arrangement of vanes or blades which act on the fluid. The rotating assembly of blades and hub is known as an impeller, a rotor, or a runner. Usually, it is contained within some form of

104 Shri TechnologiesShri Technologies housing or case.[2] This may direct the airflow or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, in- cluding hydraulic motors and internal combustion engines. Fans produce flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to a fluid stream, and devices that take advantage of this, such as anemometers and wind turbines, often have designs sim- ilar to that of a fan. Typical applications include climate control and personal thermal comfort (e.g., an electric table or floor fan), vehicle and machinery cooling systems, ventilation, fume extraction, winnowing (e.g., separating chaff of cereal grains), removing dust (e.g. in a vacuum cleaner), drying (usually in combination with heat) and to provide draft for a fire. While fans are often used to cool people, they do not actually cool air (if anything, electric fans warm it slightly due to the warming of their motors), but work by evaporative cooling of sweat and increased heat convection into the surrounding air due to the airflow from the fans. The cross-flow or tangential fan, sometimes known as a tubular fan was patented in 1893 by Paul Mortier, and is used extensively in the HVAC industry. The fan is usually long in relation to the diameter, so the flow approximately remains two-dimensional away from the ends. The CFF uses an impeller with forward curved blades, placed in a housing consisting of a rear wall and vortex wall. Unlike radial machines, the main flow moves trans- versely across the impeller, passing the blading twice. The flow within a cross-flow fan may be broken up into three distinct regions: a vortex region near the fan discharge, called an eccentric vortex, the through-flow region, and a paddling region directly opposite. Both the vortex and paddling regions are dissipative, and as a result, only a portion of the impeller imparts usable work on the flow. The cross- flow fan, or transverse fan, is thus a two-stage partial admission machine. The popularity of the cross- flow fan in the HVAC industry comes from its compactness, shape, quiet operation, and ability to pro- vide high pressure coefficient. Effectively a rectangular fan in terms of inlet and outlet geometry, the di- ameter readily scales to fit the available space, and the length is adjustable to meet flow rate require- ments for the particular application. Common household tower fans are also cross-flow fans Much of the early work focused on developing the cross-flow fan for both high and low-flow-rate condi- tions, and resulted in numerous patents. Key contributions were made by Coester, Ilberg and Sadeh, Por- ter and Markland, and Eck.

105 One phenomenon particular to the cross-flow fan is that, as the blades rotate, the local air incidence angle changes. The result is that in certain positions the blades act as compressors (pressure increase), while at other azimuthal locations the blades act as turbines (pressure decrease).Shri Technologies Repair & Maintenance of Window & Split AC

106 Shri TechnologiesShri Technologies Pshychometer & Psychometric Chart Psychrometrics or psychrometry or hygrometry are terms used to describe the field of engineering con- cerned with the determination of physical and thermodynamic properties of gas-vapor mixtures. The term derives from the Greek psuchron (ψυχρόν) meaning \"cold\" and metron (μέτρον) meaning \"means of measurement\" Although the principles of psychrometry apply to any physical system consisting of gas-vapor mixtures, the most common system of interest is the mixture of water vapor and air, because of its application in heating, ventilating, and air-conditioning and meteorology. In human terms, our thermal comfort is in large part a consequence of not just the temperature of the surrounding air, but (because we cool our- selves via perspiration) the extent to which that air is saturated with water vapor. Many substances are hygroscopic, meaning they attract water, usually in proportion to the relative hu- midity or above a critical relative humidity. Such substances include cotton, paper, cellulose, other wood products, sugar, calcium oxide (burned lime) and many chemicals and fertilizers. Industries that use these materials are concerned with relative humidity control in production and storage of such ma- terials. In industrial drying applications, such as drying paper, manufacturers usually try to achieve an opti- mum between low relative humidity, which increases the drying rate, and energy usage, which decreas- es as exhaust relative humidity increases. In many industrial applications it is important to avoid con- densation that would ruin prod- uct or cause corrosion. Molds and fungi can be con- trolled by keeping relative hu- midity low. Wood destroying fungi generally do not grow at relative humidities below 75%

107 Air FiltrationShri Technologies A particulate air filter is a device composed of fibrous materials which removes solid particulates such as Repair & Maintenance of Window & Split AC dust, pollen, mould, and bacteria from the air. A chemical air filter consists of an absorbent or catalyst for the removal of airborne molecular contaminants such as volatile organic compounds or ozone. Air filters are used in applications where air quality is important, notably in building ventilation systems and in engines. Some buildings, as well as aircraft and other man-made environments (e.g., satellites and space shuttles) use foam, pleated paper, or spun fiberglass filter elements. Another method, air ionisers, use fibers or elements with a static electric charge, which attract dust particles. The air intakes of internal combustion engines and compressors tend to use either paper, foam, or cotton filters. Oil bath filters have fallen out of favor. The tech- nology of air intake filters of gas turbines has improved significantly in recent years, due to improvements in the aerodynamics and fluid-dynamics of the air-compressor part of the Gas Turbines. Steps to change Air Filter It’s important to change an air conditioner filter at least once every few months to guarantee your air condi- tioner works at its optimal level of performance. The filter acts as a barrier between unwanted debris and the air conditioner system . Over time dirt and debris can cause an air conditioner to run poorly and can reduce the life of the unit. A properly changed filter can also prevent allergens from getting into the house and keep the air inside the house cleaner. 1. Locate the filter in the air conditioner or furnace unit.  While the central air conditioning unit, or condenser, is located outside the home and connected to the home through an electrical and airflow system of wires and tubes, the filter is usually located in the home’s ductwork or furnace unit.  Read the owner’s manual to find out where the filter is located. 2. Pull the filter compartment out of the duct or furnace.  Some filters are covered by a metal strip that must be removed to gain access to the filter. Remove any screws holding the compartment in place, and store them in a safe place so you have them after you replace the filter.

108 3. Measure the filter’s outer dimensions, and look for any identifying numbers or letters on the cas- ing.  Take measurements or the old filter with you if you’re not sure what size filter you need.  Filters come in many different varieties from the more inexpensive unit that you will need to change an air conditioner filter more often to a higher-grade filter that will trap many smaller particles and can prevent allergens from entering the air system in your home. 4.Slide the air filter into your air conditioning unit the same way the old one came out.  Make sure the filter is placed into the compartment with the correct side facing out.  Follow the directions on the package. The sides are usually marked as air-in and air-out. 5. Replace any filter cover or door that you took off to gain access to the filter compartment.  If you took any screws out to access the compartment, make sure they are all tightly replaced to pre- vent unwanted debris inside the filter compartment. Shri TechnologiesShri Technologies

109 Window Air Conditioner, Installation, Servicing, Leaks, MaintenanceShri Technologies Electrical Requirements : Repair & Maintenance of Window & Split AC Grounding Instructions This appliance is equipped with a three-prong grounding plug for protection against possible shock haz- ards. If a two-prong wall receptacle is encountered, the cus- tomer is required to contact a qualified electrician and have the two-prong wall receptacle replaced with a properly grounded three-prong wall receptacle in accordance with the National Electrical Code. Room air conditioners are designed to oper- ate according to the requirements on the nameplate and as shown in Table 1. Fuse or circuit breaker ratings must be according to the fuse instruction label and as shown in Table 1. Do not plug models marked “Use on Single Outlet Circuit Only” into a circuit with another appliance or light fixture Receptacle Wiring Receptacle wiring must be of adequate size for unit. Refer to unit identification plate for exact power re- quirements. Minimum size of wiring, based on power requirements, is: Units up to 20 amps: 12 gauge 20-30 amp units: 10 gauge Use copper wire only. The consumer’s responsibility is to provide proper and adequate receptacle wiring that conforms to all applicable codes. INSTALLATION Complete step-by-step installation instructions are furnished with your unit. These instructions will be found on a separate page included with this manual or in the mounting kit assembly. Follow these in- structions carefully. Keep these instructions with this manual for future reference. Your unit will be one of the following designs:

110 Shri TechnologiesShri Technologies •Unit with a window mounting kit These models are designed for mounting through an opening in a wall. These units can be adapted to window installation by using the optional window mounting kit sup- plied with your unit. •Unit without a window mounting kit No window mounting kit is supplied with the unit. These models are designed for mounting through an opening in a wall. These units can be adapted to window installation by purchasing an optional window mounting kit. Consult your dealer to choose the kit that is appropriate for your model and installation. Front Grill and Filter Removal The front contains an air filter that can be removed on the left or right side of the front. To clean the filter use the following method for filter removal : Grasp filter handle and slide filter out of unit. Reinstall air filter by reversing removal procedure. Front Grill and Cabinet Cleaning Grill and cabinet may be cleaned with warm water and mile soap or detergent. Cleaning and polishing compounds are not recommended as they may damage plastic surfaces.

Shri Technologies 111 Repair & Maintenance of Window & Split AC Air Filter Cleaning A dirty air filter reduces operating efficiency of unit. Filter should be inspected at least once every week during operation. Clean filter with vacuum cleaner or wash in warm water and mild detergent. Filter should be thoroughly dried before replacing in unit. Do not operate unit without filter in place. Fan Motor Care The fan motor is permanently lubricated for long life. There is no need to oil the motor. Slide-out Chassis Removal from Outer Case 1. Remove two side Phillips screws attaching case to chassis base-pan. 2. Remove two control knobs. 3. Remove two side Phillips screws attaching front panel to case. 4. If the unit has a screw holding the base-pan clip to the chassis, remove the screw. 5. Using base-pan handle, pull chassis straight out, slowly and even- ly, until approximately 9 – 12 inches extends from outer case. Use both hands to grasp base-pan and pull remaining chassis from outer case. NOTE: Base-pan clip is shipped in plastic bag with mounting screw and condensate drain cup. Install clip after reinserting chassis into outer case to prevent accidental chassis removal. Installation requirements Tools and Parts Gather the required tools and parts before starting installation. Read and follow the instructions provided with any tools listed here. Tools Needed • Flat-blade and Phillips screwdriver • Tape measure • Drill and 3/16” or smaller bit • Level Through-the-wall installation: In addition to the tools listed above, the following tools are needed for through-the-wall installation: • Saw •Wood Preservative

112 Shri Technologies •Caulk •1” (2.5cm) or thicker lumber •7 - #10 x 1” wood screws Parts supplied (on some models) Check that all parts are included in parts package Location Requirements Check the location where air conditioner will be installed. Proper installation is your responsibility. Make sure you have everything necessary for correct installation. The location should provide: •Grounded electrical outlet within 4 ft (122cm) of where the power cord exits the air conditioner. Note: Do not use an extension cord. •Free movement of air in room to be cooled. • A large enough opening for the air conditioner. • Adequate wall support for weight of air conditioner. Air conditioner weighs between 94 and 103 lbs (43 to 47kg). NOTE: Cabinet louvers must not be obstructed. Air must be able to pass freely through the cabinet louvers Window Installation Window opening measurements: •27” min to 38” max (68.6 cm to 95.5 cm) opening width. •16 ¼ min (41.3 cm) opening height.Shri Technologies

113 Through Wall Installation The wall opening measurements should be: •Height: 15 9/16” (39.5cm) plus twice the thickness of wood used to build frame. •Width: 22 13/16” (57.9 cm) plus twice the thickness of wood used to build frame Ground wire must be connected to ground screw located in lower right corner of air conditioner when air conditioner is in cabinet. The electrical ratings for your air conditioner are listed on the model and serial number label. The model and serial number label is located behind the front panel on the flange below the control panel area. Specific electrical requirements are listed in the chart below.Shri Technologies Follow the requirements for the type of plug on the power supply cord. Repair & Maintenance of Window & Split AC To test your power supply cord: 1. Plug power supply cord into a grounded 3 prong outlet. 2. Press RESET 3. Press TEST (listen for click; Reset button will trip and pop out). 4. Press and release RESET

114 Shri Technologies Unpacking AC unit Remove packaging materials. • Remove and dispose or recycle all packaging materials. • Remove tape and glue residue from surfaces before turning on the air conditioner. Rub a small amount of liquid dish soap over the adhesive with your fingers. Wipe with warm water and dry. • Do not use sharp instruments, rubbing alcohol, flammable fluids, or abrasive cleaners to remove tape or glue. These products can damage the surface of your air conditioner. • Handle air conditioner gently. 1. Remove air conditioner from carton and place it on cardboard. 2. Remove shipping screws from both sides of cabinet. 3. Remove front panel by removing 2 Phillips screws on both sides. 4. Remove both knobs from control panel. 5. Remove ground screw and ground wire from front of air conditioner base. Save ground screw. 6. Pull on handle to slide air conditioner out of cabinet. Place air conditioner on cardboard. NOTE: Do not lift, push, pull or remove any expanded polystyrene (foam) from inside the air conditioner. It is not packing material. Attach Top Channel NOTE: Attach top channel and side curtains to air conditioner cabinet before placing cabinet in window. • Locate supplied bag of screws. • Place top channel on top of air conditioner cabinet, lining up the 3 holes in top channel with 3 holes on top of air conditioner cabinet. • Using 3 - #10 x 3/8” pan-head Phillips screws, attach top channel to air conditioner cabinet.Shri Technologies

Shri Technologies 115 Repair & Maintenance of Window & Split AC Attach side curtains 1. Locate provided bag of screws 2. Insert top and then bottom of right-hand curtain housing in top and bottom curtain guides on air conditioner cabinet. (Back and Bottom View ) 3. Extend right-hand curtain outward so you may insert the first screw through the middle hole of the curtain. Using #10 x ¼” pan-head Phillips screw, screw curtain to middle hole in air conditioner cabinet. NOTE: This screw is required to correctly attach curtain (top to bottom) to the air conditioner cabinet. 4. While the right hand curtain is still extended, insert #10 x ¼” pan-head Phillips screws into the top and bottom slots of curtain. Screw Curtain to the top and bottom holes in air conditioner cabinet. NOTE: Some curtains may have 2 slots on each end. You will be able to see a mounting hole through the correct slot. 5. Slide curtain housing into guides as far as it will go. 6. Repeat above steps for left-hand curtain.

116 Attatch Foam Adhesive Seal Install Cabinet into Window • Handle air conditioner gently. • Be sure your air conditioner cabinet does not fall out of the opening dur- ing installation or removal. • The location where the power cord exits the air conditioner should be no more than 4 ft (122cm) from a grounded 3 prong outlet. Shri Technologies • Do not block the louvers on the front panel. • Do not block the louvers on the outside of the air conditioner. 1. Center empty cabinet in window. Check that lower rail of air condition- er cabinet is behind and against back side of windowsill. Maintain a firm hold on the air conditioner cabi- net. Lower window sash to hold cabinet in place. Top channel must be on inside room of window sash. 2. Measure the distance between the right-hand side of the cabinet and the inside of the window channel 3. Repeat for left side. Adjust the cabinet until the distance on each side is the same.Shri Technologies

117 4. Use a 3/16” drill bit to drill 3 starter holes ½” deep through the 3 holes in the cabinet and into the win- dow sill. 5. Attach cabinet to windowsill with 3 - #10 x ½” pan-head Phillips screws. 6. Check that the air conditioner cabinet is tilted ½ bubble on carpenters level to the outside so that water will run to the outside. Attach Side Curtains to Window Frame 1. Pull left-hand curtain out until it fits into window channel. Use a 3/32” drill bit to drill a starter hole through the hole in the curtain housing and into the lower window sash. Front view Top View 2. Insert one of the #10 x ¾” round-head screws through hole and Repair & Maintenance of Window & Split AC into lower window sash. Insert one of the #10 x ¾” round-head screws through threaded hole in top of cur- tain and one in bottom of curtain.Shri Technologies

118 Shri Technologies 3. Repeat for right-hand curtain. NOTE: Handle air conditioner gently. 1. Make sure the free end of the ground wire is outside of the cabinet. 2. Insert air conditioner into cabinet. REMEMBER: make sure the free end of the ground wire is outside of the cabinet. 3. Connect green ground wire to cabinet base with ground screw. 4. Position Ground wire pointing straight up. Put excess ground wire between coil and air conditioner cabi- net. 5. Install shipping screws on both sides of cabinet. 6. Insert front tabs of front panel into top of cabinet and swing front into place. 7. Attach bottom front of panel with front panel screws. Replace control knobs (on some models).Shri Technologies

119 NOTE: For through-the-wall installations, if needed, install molding around room side of cabinet. 8. Plug into a grounded 3 prong outlet. 9. Press RESET on the power supply cord. GENERAL OPERATING INSTRUCTIONS While operation of all units is similar, controls vary slightly from model to model. Operating Controls sec- tion shows control panel of unit purchased and gives detailed information about operation of controls. Airflow Around Unit Select the highest fan speed and set temperature control to its coldest position. When the desired tempera- ture is reached, slowly move the temperature control toward a warmer setting until the compressor shuts off. The thermostat will then cycle the compressor on and off to maintain this selected temperature. Adjust the fan speed for desired air circulation.Shri Technologies Changing airflow Direction Baffles Repair & Maintenance of Window & Split AC Airflow on unit may be diverted left or right from center by baffles. Upward and downward air discharge is provided by tilting louvers. Adjust baffles and tilt louvers for desired airflow pattern. Airflow Around Unit Check the indoor grill and outdoor louvers for obstructions to airflow. Do not block the airflow to and from the unit. If air is obstructed and/or deflected back into the unit, the air conditioner’s compressor may cycle off and on rapidly. This could damage your unit.

120 Shri TechnologiesShri Technologies Drain Cup Installation and Use Your air conditioner uses a system where the water removed from the indoor air (condensate) is channeled to the outdoor side of the unit. The outdoor fan blade has a “slinger” ring attached to it that dips into the water and slings the water onto the outdoor coil surface. This is the sound of water you hear during normal operation. The water quickly evaporates on this warm surface and improves the efficiency of your air condi- tioner. In normal conditions the unit can evaporate the water as fast as it is removed from the indoor air. However, in very humid conditions excess amounts of water may drip off the unit chassis. If this proves to be a problem, install the condensate drain cup included with the unit to route excess water where it would not be a problem (see illustration). To install, remove the unit chassis from the outercase. Insert the condensate drain cup through the recessed ½” hole on the back center of the outercase. Once inserted, place a ½” diameter hose or tube on the drain cup bottom spout. The hose allows you to route where you want the excess water to go. Reinsert the unit chassis into the outercase. The unit basepan overflow hole will be positioned directly above the drain cup and will catch any water that might run out. Operating Controls Fan Control OFF Completely shuts off the unit. To prevent blowing fuses, wait two minutes after turning the unit off before turning it on again. LOW COOL Filters and circulates room air with the fan running continuously on low speed. Also cools and dehumidifies while the compressor is running. Select this setting for quiet cooling operation.

121 HIGH COOL Filters and circulates room air with the fan running continuously on high speed. Also cools and dehumidifies while the compressor is running. Se- lect this setting for maximum air circulation and cool- ing effect. LOW HEAT Filters and circulates room air with the fan running continuously on low speed. Also heats Repair & Maintenance of Window & Split AC while the compressor or electric heat is running. Select this setting for quiet heating operation. HIGH HEAT Filters and circulates room air with the fan running continuously on high speed. Also heats while the compressor or electric heater is running. Select this setting for maximum air circulation and heating effect. FAN ONLY Select this setting for circulating or exhausting room air without cooling. Temperature Control Turn this control to the left for a warmer room temperature, to the right for a cooler temperature. Vent Control (On Some Models) Choose one of the following two settings by sliding the vent control under the appropriate marking: EXHAUST Exhausts room air to the outdoors. Also circulates and filters room air. This position can be used to exhaust stale or smoky air. To conserve energy, it is advised that the Fan Control be in the Fan On- ly setting when using this feature. CLOSED Exhaust damper is closed. Unit circulates and filters room air. This position should be used for normal cooling operation.Shri Technologies

122 Shri TechnologiesShri Technologies Split Type AC Installation, Servicing Required tools for installation  Phillips screwdriver  Level  Scale  Utility Knife or Scissor  Torque Wrench  Wrench or Spanner  4mm (5/32 in.) hexagonal wrench  Flare toll for R410A  Gauge Manifold for R410A  Vaccum Pump for R410A  Charge hose for R410A  Pipe cutter with reamer Install the Indoor Unit Select an unobstructed location on your interior wall to mount the indoor air conditioning unit.  Avoid direct sunlight and heat sources.  Avoid locations where gas may leak or where oil mist or sulphur exists.  The indoor unit requires at least 6\" (15 cm) of open space surrounding its top and sides. The unit should also be mounted at least 7 feet (2.13 m) above the ground.  Install the unit at least 3.3 feet (1 m) away from an- tenna, power or connecting lines that are used for television, radio, home security systems, intercoms or tel- ephones. The electrical noise from these sources could cause operational problems for your air conditioner.  The wall should be strong enough to hold the unit's weight. You may need to construct a wood or metal frame to provide added support

123 Secure the mounting plate to the interior wall.  Hold the mounting plate against the wall where you want to install the indoor unit.  Use a level to make sure the plate is both horizon- tally and vertically square.  Drill holes into the wall at the appropriate spots to affix the plate to the wall. Insert plastic anchors into the holes. Secure the plate to the wall with tapping screws Create a hole in the wall to fit the piping.  Find the best spot for the hole to the exterior based on the opening in the mounting bracket. You should al- so consider the length of the pipe and the distance that it needs to travel to reach the outside unit.  Drill a hole that is 3\" (7.5 cm) in diameter through the wall. The hole should slope downward toward the exterior to ensure adequate drainage.  Insert a flexible flange into the hole. Check the electrical connections. Repair & Maintenance of Window & Split AC  Lift the unit’s front panel and remove the cover.  Be sure the cable wires are connected to the screw terminals. Also, make sure that they match the dia- gram that comes with the unitShri Technologies

124 Shri TechnologiesShri Technologies Connect the pipes.  Run the piping from the indoor unit toward the hole drilled through the wall. Minimize bending to en- sure that the unit performs well.  Cut a length of PVC pipe 1/4\" (6 millimeters) shorter than the length between your interior and exteri- or wall surfaces.  Place the pipe cap on the interior end of the PVC pipe. Insert the pipe into the hole in the wall.  Bind the copper pipes, the power cables and the drain pipe together with electrical tape. Place the drain pipe on the bottom to ensure a free flow of water.  Secure the pipe to the indoor unit. Use 2 wrenches, working in opposite directions, to tighten the con- nection.  Join the water drainage pipe to the indoor unit’s base.  Run the bound pipes and cables through the hole in the wall. Make sure that the drainage pipe allows water to drain in an appropriate place. Secure the indoor unit to the mounting plate by press- ing the unit against the mounting plate. Install the Outdoor Condenser Choose the best place to install the outdoor unit. 1. Decide the mounting position with the customer as follows: 2. Install the outdoor unit in a location which can withstand the weight of the unit and vibration, and which can install horizontally. 3. Provide the indicated space to ensure good airflow. 4. If possible, do not install the unit where it will be exposed to direct sunlight. 5. If necessary, install a blind that does not interfere with the airflow.) 6. Do not install the unit near a source of heat, steam, or flammable gas. 7. During heating operation, drain water flows from the outdoor unit.

Shri Technologies 125 Repair & Maintenance of Window & Split AC Therefore, install the outdoor unit in a place where the drain water flow will not be obstructed. (Reverse cycle model only) 6 Do not install the unit where strong wind blows or where it is very dusty. 7 Do not install the unit where people pass. 8 Install the outdoor unit in a place where it will be free from being dirty or getting wet by rain as much as possible. 9 Install the unit where connection to the indoor unit is easy. Lay the concrete pad on the ground and make sure that it is level. The pad should be high enough so that the condenser will sit above the level of winter snows.  Set the outdoor condenser on top of the pad. Use rubber cushioning under the unit's feet to mini- mize vibration. Make sure that no antenna of a radio or television is within 10 feet (3 meters) of the outdoor condenser Connect the electrical wires.  Remove the cover.  Refer to the unit’s wiring diagram and make sure the cable wires are connected as the diagram suggests. Following the manufacturer's instructions for wiring is crucial.  Fasten the cables with a cable clamp and replace the cover. Secure the pipes’ flare nuts to the corresponding pipes on the outdoor unit

126 Shri Technologies Bleed the air and humidity from the refrigerant cir- cuit.  Remove the caps from the 2-way and 3-way valves and from the service port.  Connect a vacuum pump hose to the service port.  Turn the vacuum on until it reaches an absolute vacuum of 10mm Hg.  Close the low pressure knob and then turn off the vacuum.  Test all of the valves and joints for leaks.  Disconnect the vacuum. Replace the service port and caps. Wrap the joints of the piping with insulating cover- ing and insulating tape Affix the piping to the wall with clampsShri Technologies

127 Seal up the hole in the wall using expanding polyu- rethane foam.Shri Technologies Repair & Maintenance of Window & Split AC

128 Shri TechnologiesShri Technologies Charging, Evacuation & Purging This procedure outlines the steps to perform a complete charge. These steps are not to be used to refill or make partial charges. Toping off requires system parameters monitoring and knowledge, specially in R134a-based system. Excessive gas will harm your system and will keep it from cooling properly. MORE REFRIGERANT DOES NOT MEAN COLDER TEMPERATURES CHARGING IN GAS OR LIQUID Do not use the sight glass (if so equipped) in R134a-based systems as if were R-12 based. SPECIAL EQUIPMENT REQUIRED 1) Vacuum pump 2) Gauges (R12 or R134a) 3) Service port adapter (as required in most R12-based systems) R134a systems do not require adapters other than the couplers in your gauges in the majority of applications 4) Refrigerant gas (R12 or R134a) 5) Optional: 2-3 ounces of specified oil. Procedure 1. Make sure what is the required amount of gas. From factory, all systems have a decal under the hood that give the data. It is very important to know if your system has oil. Oil starvation is the main reason of compressor failure. Oil can be added to the system in two ways: with oil injectors or through the low side port under vacuum. 2. Connect both blue and red gauge hoses to the system's service ports. The discharge port (red hose) is located somewhere between the compressor and expansion device, either before the condenser or after it. In R134a systems, the port is the thicker of both, while in R12 systems is the thinner one. In some aftermar- ket systems, the port is located in the back of the compressor. If your ports are located in the compressor, the low side is marked by an \"S\" and the high side by an \"H\". Port caps have an \"L\" for low or \"H\" for high. 3. Open both gauge valves. Connect the common hose (yellow one) to the vacuum pump. Make sure both gauge needles are zeroed down. Needle is adjusted by turning a fine screw inside the dial. You must re- move the plastic lens to do this.

Shri Technologies 129 Repair & Maintenance of Window & Split AC 4. Turn the pump on. You'll notice that both gauge readings begin to drop. The blue gauge's needle will even dip into negative values. The desired low side reading should be less than -25, while the high side will remain at 0. 5. After approximately 5 minutes, close both gauge valves. Turn the pump off, and observe the needles. Any movement will indicate vacuum loss. The faster the movement, the greater the loss. If after two minutes you don't see any needle movement, open both valves, turn the pump on, and continue vacuum for not less than 30 minutes. Close both valves then turn the pump off. 6. Get ready to charge. Have the necessary refrigerant amount handy. Cans make charging easier and more precise unless you have a charging cylinder or a precision scale. 7. Disconnect the yellow hose from the vacuum pump and connect it to the can tap or charging cylinder valve. You can charge in two ways: liquid (can upside down) or gas. Liquid charging is a lot faster but not recommended unless you extreme care or have experience. Traditional (gas) charging is slower but safer. 8. Once you've decided, and with the can or container connected, unscrew the top yellow hose connection (at the gauges) allowing refrigerant to escape for a couple of seconds. This will purge the air out of the hoses so you make sure that all you dispense is refrigerant. You can do this venting in liquid form so you can see when a fine, steady stream of refrigerant escapes indicating that all the air is gone from the hose. Don't breathe refrigerant and don't charge in a flammable environment. 9. \"Flood\" the system with liquid refrigerant (can upside down) by opening the red valve (high side) until it won't take anymore. Close the red valve. Jump the low pressure cycling switch (if so equipped).. 10. Turn the machine on. Turn the A/C into MAX on its third or higher blower speed. You'll note that both gauge readings are now positive. The red gauge should read between 100 and 150, while the blue gauge between 5 and 15. If you are charging with cans, don't forget to purge air out the hose after hooking a new can as described in step 8 above. Now, charge will continue through the low (blue) side (see note below) . If you haven't jumpered any switch (you don't have to), you'll notice the compressor cycling fre- quently on and off. That is normal. The cycling will disappear as you dispense more refrigerant. The only disadvantage of frequent compressor cycling is that charge will take longer. Needles will move up and down with every cycle. This is normal. Do not jump any switch unless you are absolutely certain!.

130 Shri TechnologiesShri Technologies GAS OR LIQUID CHARGING? There are two ways to charge: gas (can or cylinder up), or liquid (can or cylinder upside down). A compres- sor is designed to compress gas. Direct liquid charge will harm the compressor if suction pressure is not controlled. Liquid charging is faster, yet is riskier. Liquid charging should be made by professionals or un- der supervision. Liquid charging can be done if the suction port is away from the compressor (some com- pressors have the suction valve in its body). Liquid charging can be done never exceeding a 50 PSI suction pressure. If you can't control it, charge in gas form. In cooler weather, cans may freeze. You may immerse them in water and shake them while charging. 11. Once about 2/3 of the charge has been dispensed into the system, spray water in the condenser to opti- mize heat exchange and speed the process. When you get the condenser wet, vent temperature is likely to raise. This is normal. You'll also note pressure drop in both gauges. 12. Once the specified amount has been dispensed, close the blue valve. Let the system run for a minute. Turn the A/C off and then the engine. Wait another minute and disconnect the couplers from the service ports. Disconnect the low side first. If you jumpered a switch, reconnect it too. Optimum cooling performance is attained after 10 minutes of operation. Our own acceptance criteria is at least 50 F in the center vent to the driver side at idle after 10 minutes or less. Remember: cooling increases while the vehicle is in motion. VERY IMPORTANT Due to the physical properties and chemical composition, R134a and R12 charging amounts are different. Never, if you are retrofitting, charge the same or specified amount of R12 with R134a. Do not use this proce- dure if you are using any other refrigerant. This is just for R12 or R134a. Although procedures and parame- ters may be similar, HOW TO DETERMINE OPERATING PRESSURES Every vehicle has its own operation parameters specification. Depending on whether or not the vehicle has a factory or an after market system, and whether it was retrofitted or is still original, among others. There is no established calculation to determine the exact operating pressures. The low pressure (blue gauge) should be 35 or less at idle, regardless of the type of gas. Only if you're run- ning a dual system, the low pressure may be between 45 and 50 at idle.

Shri Technologies 131 Repair & Maintenance of Window & Split AC The high pressure, for starters, is directly related to ambient temperature: the higher the temperature, the higher the higher the pressure. Bear in mind that dispensing a complete charge without lowering the pressures with water will result in higher readings. This is normal, and that is why you should spray water in the condenser at 2/3rds of the charge or once you have completed it. You'll note an immediate pressure drop when you spray water in the condenser. To obtain a ballpark high side value, multiply ambient temperature by 2.2 if you have an R12 system. If you have a factory R134a system, use 2.3. To convert C to F, use this formula: C X 1.8 + 32. Purging: With both valves closed on A/C manifold gage set, at- tach red hose (high pressure) to discharge fitting (2) and blue hose (low pressure) to suction fitting (1) 1. Suction fitting 2. Discharge fitting Place yellow hose in a clean rag Slowly open low and high pressure valves on gauge set allow freon to bleed off through yellow hose Check rag for signs of oil, a small amount is to be expected. Replace oil if loss is excessive. When both gauges read zero, system is purged. Close valves on gauge set, and leave lines connected for evacuation Find the service ports Central air conditioning systems, heat pumps, and split systems typically have service ports installed spe- cifically for the attachment of test gauges for system inspection, evacuation, and charging.

132 Shri TechnologiesShri Technologies Residential refrigerators, freezers, and window or portable air conditioners typically will not have these service ports. To service one of those latter devices you'll need to cut the refrigerant line and install (solder in place) a tee and a service port. Our photo (left) shows four covered service ports on this split system compressor/condenser unit. That's because this unit supports two indoor wall-mounted cooling units. If its not obvious to you that the larger diameter line is the low pressure or suction side and the smaller di- ameter refrigerant line is the high pressure side, then really you should not be messing with this equipment before taking a refresher class in HVAC Using Temporary Access Valves for HVAC or Refrigeration Testing & Diagnosis Tapaline and other piercing valves are available in various sizes to allow the HVAC technician to tap into the refrigerant lines on a system in order to perform diagnosis where there are not already service valves installed. Smaller bullet-type valves are installed using an allen wrench. Use these valves as a temporary service tool, preferably attached on the process tube. [See Types of air con- ditioner or heat pump compressors & compressor designs if you don't know what a process tube is.] Watch out: do not leave these temporary test valves on the refrigerant piping - you're asking for a future leak. These valves are suitable to aid diagnosis of a refrigeration system by avoiding disturbing the trou- bled state of the system (as you'd do if you had to cut lines and solder in service valves just to do a test). After using a temporary tap-in valve on the process tube at a compressor unit, you should solder off the line puncture and add a permanent service valve fitting - the type that uses a schrader valve and cap - also referred to as an access valve or line valve. Connect the Test Gauges to the Air Conditioner, Heat Pump, etc In the shop we connect both high and low pressure gauges to the equipment being tested. In the field tech- nicians often use only the low pressure side of the HVAC test gauge set, since high side problems also show up on the low side.

133 On test gauge sets such as ours shown here, the service lines always open or close a connection between the HVAC equipment refrigeration test ports and the gauges. The end-valves (silver handles) on either side of the gauge set then open or close a further connection between that valve and either high or low side connection and the yel- low hose that will in turn connect to a refrigerant source. You'll notice in our photo that both ends of the refrigerant hoses are attached to the gauge set. On the front of this gauge (and more easily seen in the photograph) are three blind connector plugs to which we connect the hoses when the gauge is not in use - this step is to help keep the gauge hoses clean of debris. In the photo at left, the \"live\" hose connection ports are somewhat hidden behind the gang of hoses and the \"blind\" connectors used to keep the hoses and their end connectors clean when not in use. The gauge set has stop valve handles that you see on either side of the gauge. These controls open or close the high or low side service lines once they have been properly connected to the high or low side service port. As we've mentioned before, we would not normally connect our gauge set to the service ports without Repair & Maintenance of Window & Split AC first attaching a can of the proper refrigerant to the gauge set service port and then using that refrigerant to purge any air that may be in the refrigerant hoses. That's to avoid blowing air and contaminants into the HVAC system. On our air conditioner or heat pump test gauges we use aShri Technologies  A blue flexible hose on the low-side gauge. In the photo above the blue hose is connected to the left- hand low pressure gauge port, while its free end is connected to a right-hand blind port. When in use the free end of the low pressure gauge is removed from its \"blind port\" and is then connected to the low side of the system at that service port. [Click to enlarge any photo to see more detail]  A red hose on the high side gauge. In the photo the red hose is connected to the right-hand high pres-

134 sure gauge and its free end - the end that will connect to the HVAC equipment test gauge port - is connect- ed to a left-hand blind port to keep the fitting clean when not in use. The high pressure gauge (red hose) will be connected to the high side of the system at that service port.  A yellow hose on the center gauge service port just to help avoid any confusion in the field. The free end of the yellow hose is also connected to a center blind port to keep out debris. The center service port on the gauge set will connected to a refrigerant canister, charging device, or to an evacuator pump, depending on what the HVAC technician needs to do. Depending on which valves you open or close, this gauge set permits charging the refrigerant system on either the high side or the low side. Shri TechnologiesShri Technologies

135 Trouble Shooting (Causes and Remedying)Shri Technologies HVAC units are usually very reliable, however problems do arise. Some of these problems can be do-it- Repair & Maintenance of Window & Split AC yourself issues. However, for the more complex problems, it is best to call a trained technician. When a service call is placed for a technician to come out and check a unit because a client is not getting any heat- ing or cooling, these are the most common things that we check: 1. Blown Fuses. Fuses protect the unit's motor or compressor against overheating, and is found in the evaporator coil. When a motor is suspected of going bad, the breaker is one of the first things the techni- cian checks. 2. Worn Contactor. There are three contactors in a unit: one for the compressor, one for the condenser fan motor, and one for the blower motor. The contactors engage when there is a need for cooling or heat- ing, making an electrical connection. This starts the compressor and motors. Arcing and pitting can form on the contactor making it hard for the electrical current to pass and start the particular motor. 3. Capacitors. The run capacitor is used to help the motors of the unit run at a consistent speed, rated in microfarads. Start capacitors give the compressor a brief increase in starting torque. If either capacitor burns out, it will need to be replaced for your HVAC to work properly. 4. Gas valve. The gas valve meters the gas to flow from your gas line to your unit. They are only used during the heating season. Sometimes the gas valve gets corroded. If this is the case, it will need to be replaced. 5. Filters. Filters get dirty and clogged from air particles. Once this happens, the filter needs to be changed. One way to tell if the filter needs to be changed is to hold it up to the light and see if you can see light pass through it. If you cannot, the filter needs to be changed. A dirty filter will reduce the air flow to the unit causing the unit to freeze. 6. Thermostat. This is the device that tells the system what to do and when to do it. Before calling an HVAC company, make sure the thermostat is on. Many times the thermostat is accidentally turned off or is on the wrong setting. 7. Drain lines. The drain line commonly becomes clogged with dirt or algae. If it is clogged, the drain pan will fill up and cause water to leak over and create water damage. 8. Refrigerant leak. Refrigerant leaks can happen with vibration of the unit while it is operating. Re- frigerant leaks in the condenser or evaporator coils cannot be repaired. If the leak is found in another place the technician can remove what is left and charge the unit levels back to their correct amount.

136 Shri TechnologiesShri Technologies 9. Compressor. This is the heart of the A/C unit. The compressor is located with the condenser coil. If the unit is undercharged with refrigerant, the compressor will run hot and will eventually seize. If the unit is overcharged, your liquid refrigerant will get back to the compressor and cause liquid slugging. It is im- portant that the A/C unit has the proper amount of refrigerant . 10. Condenser Coil. These are located outside with the compressor. They are exposed to the outdoor ele- ments, so they often get dirty and should be cleaned at least yearly. This can be done with a water hose when the unit is not operating. If the dirt and grime get bad enough an HVAC technician will have to clean the coil with a chemical cleaner. 11. Evaporator Coil. On split systems the evaporator coil is located in the attic, but on a package unit it is located outside with rest of the unit. If the coil is located inside, cleaning will only be necessary if suggest- ed and should only be about every three years or so. If the evaporator coil cracks, an HVAC professional will need to fix the break. The following is a list of problems that are sometimes encountered when using a room air conditioner. Possible cause and suggested remedies are given for each problem. • UNIT WILL NOT RUN Push reset button on power cord. Set Fan control to position other than OFF. Make sure plug is firmly seat- ed in outlet. Check for blown fuses, tripped circuit breakers. • LITTLE OR NO COOLING OR HEATING, (Fan and Compressor run) Set vent to CLOSED Remove obstruction from indoor grill or outdoor louvers. Dirty air filter. Clean or replace as needed. Check with dealer to determine proper capacity unit for appli- cation. • LITTLE OR NO COOLING OR HEATING, (only fan runs) For cooling, turn Temperature Control to cooler setting. For heating, turn Temperature Control to warmer setting. • NOISY UNIT Tighten any loose parts Provide additional support for unit. Normal in high humidity. Stop noise by re- moving drain plug or adding condensate drain cup. Check with dealer to determine proper capacity unit for application.

137 • MOUNTING SUPPORT NOT INSTALLED Some models require removal of storm window frame before installation. • FROST ON INDOOR COIL Clean air filter by vacuuming or washing with water and mild soap. Turning Temperature Control to warmer setting reduces occurrence and duration of frost. • ODORS IN COOLING To reduce algae growth, use an algaecide tablet in base pan; remove drain plug; add condensate drain cup and hose. Thoroughly clean unit. • ODORS IN HEATING Caused by dust accumulation during unused months. Odor dissipates quickly with heater use.Shri Technologies Repair & Maintenance of Window & Split AC

138 Problems of AC Mechanic Some of the problems faced by AC Mechanic are: 1. Deal in excessive temperatures 2. Deal with Electrical equipment’s 3. It is a job which requires the person to be mobile 4. Has to work in places which are not accessible under normal circumstances 5. Deal with refrigerants which are dangerous if proper precautions are not taken care 6. Must be well versed with the different tools and techniques any changes would result in dangerous con- sequences. 7. Must communicate effectively with customers and supervisors 8. Work away from home 9. Carry / Deal with weights 10. Deal with angry customers Shri TechnologiesShri Technologies

139 Customer A customer (sometimes known as a client, buyer, or purchaser) is the recipient of a good, service, prod- uct, or idea, obtained from a seller, vendor, or supplier for a monetary or other valuable consideration. Customers are generally categorized into two types:  An intermediate customer or trade customer (more informally: \"the trade\") who is a dealer that pur- chases goods for re-sale.  An ultimate customer who does not in turn re-sell the things bought but either passes them to the consumer or actually is the consumer. A customer may or may not also be a consumer, but the two notions are distinct, even though the terms Repair & Maintenance of Window & Split AC are commonly confused. A customer purchases goods; a consumer uses them. An ultimate customer may be a consumer as well, but just as equally may have purchased items for someone else to consume. An intermediate customer is not a consumer at all. The situation is somewhat complicated in that ultimate customers of so-called industrial goods and services (who are entities such as government bodies, manu- facturers, and educational and medical institutions) either themselves use up the goods and services that they buy, or incorporate them into other finished products, and so are technically consumers, too. How- ever, they are rarely called that, but are rather called industrial customers or business-to-business cus- tomers. Similarly, customers who buy services rather than goods are rarely called consumers. Five main types of customer are:Shri Technologies  Loyal Customers: They represent no more than 20 percent of our customer base, but make up more than 50 percent of our sales.  Discount Customers: They shop our stores frequently, but make their decisions based on the size of our markdowns.  Impulse Customers: They do not have buying a particular item at the top of their “To Do” list, but come into the store on a whim. They will purchase what seems good at the time.  Need-Based Customers: They have a specific intention to buy a particular type of item.  Wandering Customers: They have no specific need or desire in mind when they come into the store. Rather, they want a sense of experience and/or community.

140 Shri TechnologiesShri Technologies The tips below can help navigate the drama some difficult customers may deliver. 1. Let your customers communicate how they feel. First and foremost, giving your customers time and space to “vent” is often all they need to help move forward towards resolution or at the very least… results. After they have finished expressing their feelings, apologize for their unhappiness towards your business – even if you do not feel they have been let down in any- way. It’s simply showing you support them in their role as a customer. Having genuine care towards their feelings certainly helps, as well. 2. Listen to your customers and their viewpoint of the problem. Even if their viewpoint is not your viewpoint, try and deliver a response that shows you respect their opinion. If they are chal- lenging your return policy, for example, state why it’s in place and why it must be enforced. In some situations, such as a response to a customer service scenario, you may even agree entirely with their perspective – in which case you should acknowledge your understanding of their view and offer a resolution to ease their frustration. When it comes to easing a vendor issue, you can ex- plain your lack of immediate control but your willingness to help them navigate the problem. By offering an explanation and offering a willingness to help, customers are more likely to embrace your support instead of shunning your business. 3. Fix the problem at hand immediately. If you can provide an immediate response to the problem at hand, do it. This may mean breaking your own rules every now and again… but then again, isn’t that why you are the boss, manager or in an authority position? While this won’t – and shouldn’t be – the answer for all difficult customer situations, having the flexibility to quickly respond to diffi- cult customers should be considered. For example – when a customer is creating a scene in front of other customers, you should aim to resolve it as fast and quietly as possible. Retailers in particular know how hard this can be, as having an audience within a store is never ideal when dealing with customers who are acting upset or rude. The main goal is to leave your disgruntled customer feel- ing satisfied that they have experienced valued customer service. One of the main reasons for this is that any customer who becomes upset and loud about it in your business is likely the same type of person to talk about this experience with friends, family and other potential customers.

141 Safety Precaution & First AidsShri Technologies In the interest of promoting safety in the refrigeration and air Repair & Maintenance of Window & Split AC conditioning industry, Tecumseh Products Company has pre- pared the following information to assist service personnel in safely installing and servicing equipment. This article covers a number of topics related to safety. However, it is not designed to be comprehensive or to replace the training required for professional service personnel. Trained Personnel Only Refrigeration and air conditioning devices are extremely complicated by nature. Servicing, repairing, and troubleshooting these products should be done only by those with the necessary knowledge, training, and equipment. WARNING: Improper servicing can lead to serious injury or death from fire, electric shock, or explosion. Terminal Venting and Electrocution Improperly servicing, repairing, or troubleshooting a compressor can lead to electrocution or fire due to terminal venting with ignition. Follow the precautions below to avoid serious injury or death from elec- trocution or terminal venting with ignition. A. Fire Hazard From Terminal Venting With Ignition Oil and refrigerant can spray out of the compressor if one of the terminal pins is ejected from the hermet- ic terminal. This \"terminal venting\" can occur as a result of a ground fault (also known as a short circuit to ground) in the compressor. The oil and refrigerant spray from terminal venting can be ignited by elec- tricity and produce flames that can lead to serious burns or death. When spray from terminal venting is ignited this is called \"terminal venting with ignition.\" B. Terminal Venting And Electrocution Precautions To reduce the risk of electrocution, serious burns, or death from terminal venting with ignition:  ·Disconnect ALL electrical power before removing the compressor’s protective terminal cover. Make sure that all power legs are open. (NOTE: The system may have more than one power supply.)

142 Shri TechnologiesShri Technologies  Never energize the system unless: (1) the compressor’s protective terminal cover is securely fastened, and (2) the compressor is properly connected to ground.  Never reset a breaker or replace a fuse without first checking for a ground fault (a short circuit to ground). An open fuse or tripped circuit breaker is a strong indication of a ground fault.  Be alert for sounds of arcing (sizzling, sputtering, or popping) inside the compressor. If you hear these sounds, IMMEDIATELY get away.  Disconnect power before servicing. Always disconnect power before servicing, unless it is required for a specific troubleshooting technique. In these situations, use extreme caution to avoid electric shock. Refrigerants And Other Chemicals Contact with refrigerant, mixtures of refrigerant and oil, or other chemicals can cause a variety of injuries including burns and frostbite. For example, if refrigerant contacts skin or eyes, it can cause severe frostbite. Also, in the event of a compressor motor failure, some refrigerant and oil mixtures can be acidic and cause chemical burns. To avoid injury, wear appropriate protective eyewear, gloves, and clothing when servicing an air condi- tioning or refrigeration system. Refer to your refrigerant supplier for more information. If refrigerant or mixtures of refrigerant and oil come in contact with skin or eyes, flush the exposed area with water and get medical attention immediately. Compressor Removal Failure to properly remove the compressor can result in serious injury or death from electrocution, fire, or sudden release of refrigerant and oil. Follow these precautions when removing a compressor from a system:  Disconnect ALL electrical power. Disconnect all electrical power supplies to the system, making sure that all power legs are open. (NOTE: The system may have more than one power supply.)  Be sure refrigerant is recovered before removing compressor. Attempting to remove the compressor before removing all refrigerant from the system can cause a sudden

143 release of refrigerant and oil. Among other things, this can: 1. Cause a variety of injuries including burns and frostbite. 2. Cause a fire if a torch is used to disconnect tubing. 3. Expose the service person to toxic gas. To avoid serious injury or death, be sure to remove and recover all refrigerant before removing the com- pressor.  Use a tubing cutter, not a torch. Use a tubing cutter to remove the compressor. A torch can cause even trace amounts of refrigerant to decom- pose and release toxic fumes. In addition, using a torch to remove the compressor can cause a fire. If you ignore this recommendation and use a torch, be prepared to extinguish a fire. Figure 1. Dry nitrogen cylinder with attached pressure regulating and relief valves and pressure gauges needed for pressure testing for leaks and purging. System Flushing, Purging, And Pressure Testing For Leaks Failure to properly flush, purge, or pressure test a system for leaks can result in serious injury or death Repair & Maintenance of Window & Split AC from explosion, fire, or contact with acid-saturated refrigerant or oil mists.Shri Technologies  Follow these precautions when flushing/purging a system or pressure testing a system for leaks:  Use flushing products according to the manufacturer’s instructions.  To purge a system, use only dry nitrogen.  When pressure testing for leaks, use only regulated dry nitrogen or dry nitrogen plus trace amounts of the serial label refrigerant.  When purging or pressure testing any refrigeration or air conditioning system for leaks, never use air, oxygen, or acetylene. 1. Oxygen can explode on contact with oil. 2. Acetylene can decompose and explode when exposed to pressures greater than approximately 15 psig.

144 Shri TechnologiesShri Technologies 3. Combining an oxidizing gas, such as oxygen or air, with an HCFC or HFC refrigerant under pressure can result in a fire or explosion.  Use a pressure regulating valve and pressure gauges. Commercial cylinders of nitrogen contain pressures in excess of 2,000 psig at 70 degrees F. At pressures much lower than 2,000 psig, compressors can explode and cause serious injury or death. To avoid over- pressurizing the system, always use a pressure regulating valve on the nitrogen cylinder discharge (see Figure 1). The pressure regulator must be able to reduce the pressure down to 1 or 2 psig and maintain this pressure. The regulating valve must be equipped with two pressure gauges: 1. One gauge to measure cylinder pressure; and 2. One gauge to measure discharge or downstream pressure.  Use a pressure relief valve. In addition to a pressure regulating valve and gauges, always install a pressure relief valve. This can also be a frangible disc-type pressure relief device. This device should have a discharge port of at least 1/2-inch MPT size. The valve or frangible disc device must be set to release at 175 psig (see Figure 1).  Do not pressurize the system beyond 150 psig field leak test pressure. When field testing a system for leaks, 150 psig is adequate test pressure.  Disconnect nitrogen cylinder and evacuate the system before connecting the refrigerant container. Disconnect the nitrogen cylinder and release the pressure in the system before connecting a refrigerant container to the system. The higher pressure gas in the system can explode the refrigerant container. System Charging Failure to properly charge the system can result in serious injury or death from explosion or fire. Follow these precautions when charging a system:  Do not operate the compressor without charge in the system. Operating the compressor without a charge in the system can damage the hermetic terminal. As always, to

Shri Technologies 145 Repair & Maintenance of Window & Split AC avoid serious injury or death from terminal venting with ignition, never energize the compressor unless the protective terminal cover is securely fastened.  Use proper refrigerant. Use only the serial label refrigerant when charging the system. Using a different refrigerant can lead to excess system pressure and an explosion. Use of a refrigerant other than the serial label refrigerant will void the compressor warranty.  Do not overcharge a refrigeration or air conditioning system. Overcharging a refrigeration or air conditioning system can result in an explosion. To avoid serious inju- ry or death, never overcharge the system. Always use proper charging techniques. Limit charge amounts to those specified on the system equipment serial label or in the original equipment manufacturer's ser- vice information. Overcharging the system immerses the compressor motor, piston, connecting rods, and cylinders in liq- uid refrigerant. This creates a hydraulic block preventing the compressor from starting. The hydraulic block is also known as locked rotor Continued supply of electricity to the system causes heat to build in the compressor. This heat will even- tually vaporize the refrigerant and rapidly increase system pressure. If, for any reason, the thermal pro- tector fails to open the electrical circuit, system pressure can rise to high enough levels to cause a com- pressor housing explosion. Prevention Of Water-Utilizing System Explosions In certain water-utilizing refrigeration systems, water can leak into the refrigerant side of the system. This can lead to an explosion of system components, including but not limited to, the compressor. If such an explosion occurs, the resulting blast can kill or seriously injure anyone in the vicinity. A. Systems At Risk Of Explosion Water-utilizing systems that have single-wall heat exchangers may present a risk of explosion. Such sys- tems may include:  Water source heat pump/air conditioning systems; and  Water cooling systems, such as icemakers, water coolers, and juice dispensers. Water-utilizing systems that have single-wall heat exchangers present a risk of explosion unless they