Troubleshooting an Air Conditioner that is Not Blowing Cold Air Troubles with an air conditioner are never great, but it is especially a problem when it seems your air conditioner is making your home warmer! 

There is never a worse time to discover that your AC is blowing warm air than the middle of a hot Kansas summer.

 When you realize your air conditioner is putting out warm air instead of cool air, what should you do? 

It may seem like your system is completely broken and that you will need a costly repair or even an even more expensive complete AC replacement. 

But the good news is that isn’t always the case.

 There may be some easy fix that just about any homeowner can handle to get the hot air problem fixed right away.

 What Should You Do 

When Your AC is Blowing Warm Air?

 The first thing you should NOT do is panic and rush for the phone to call for a repair. 

Yes, we would be happy to fix your air conditioning problem whenever you need us, but if there is an easy fix, doing it yourself will save you some time and money. 

So before calling a professional cooling technician, we want to give you the AC Blowing 

Warm Air Troubleshooting Tips you should try first.

 Troubleshooting AC Blowing Warm Air Here are the first steps for a homeowner to take when faced with an air conditioner is not blowing cool air. 

These are pretty basic steps that just about anyone at any skill level can handle.

 Are relatively easy and require no , repair skills Can be done quickly, often in mere minutes Taking a little bit of time to troubleshoot your AC problem could really pay off. 

If one of these troubleshooting steps fixes your problems, you will have prevented paying for a service call. 

Check your air conditioner THERMOSTAT You are going to hope the thermostat is your problem because it can be the easiest problem to fix! 

Getting your air conditioner to blow cool air again may be as simple as a push of a button. 

 We see this problem every so often: someone in the home changes the thermostat. 

Whether they intentionally wanted it much warmer or simply hit something wrong by accident, there could be a setting that is making your AC blow warm air. 

 Checking to ensure that your thermostat settings are where they should be is your first step. 

 Is the thermostat set to COOL? No matter how low you set your thermostat it, if it’s not at the COOL setting, it won’t put out cool air. 

You need to make sure the thermostat is indeed set on COOL. It should not be only on FAN or HEAT.

 Is the thermostat set to be colder than the current temperature? 

If you haven’t adjusted your thermostat since the winter, it may be set to a hotter temperature than the ambient temperature. 

If that’s the case, lower the set temperature to be a number below the current air temperature. You should notice your air conditioner fan kick on rather quickly. 

And soon after, you should feel cool air coming from your vents. Is the thermostat’s battery dead?

 A lot of us forget that the device controlling our temperatures needs battery power to work. If that battery is dead, it can’t send the message to your HVAC system the message that your house is too hot.

 It is great news if you discover this is your problem. Simply replacing your thermostat’s batteries may be all the fix you need to get your air conditioner back to working and blowing out cool air.

 This step is to simply check all the vents in your home. Are your vents open? 

For proper heating and cooling to occur, you need to keep every vent in your home open. 

It’s a common mistaken belief that closing vents to rooms saves energy. However, your HVAC system was designed to work in the way it was set up, including utilizing your full duct work system. 

Vents should be open for proper flow of air through your home. It is okay, however, if a couple vents are closed. 

 Make sure you can feel air coming out of your registers. If you do not feel any, the fan motor in your HVAC system may not be working. Call us at (air conditioner repair LTD.)  and our technicians can get that fixed quickly. Your home’s HVAC includes a component of the AC system called an evaporator. The evaporator absorbs heat from the air and transfers it to your outdoor AC unit (the condenser). 

To check this step, go to your furnace and listen if the blower motor is running. Also, check to see if there is any ice on the evaporator coil. 

That may indicate there is a refrigerant leak or something simpler to address such as a dirty air filter (keep reading for more on air filters).

 If your evaporator mower is not working, you will want to contact a professional air conditioning technician to handle.

 There are a few issues that could be keeping the motor from working, from lack of lubrication to electrical issues, and these are most safely handled by a trained technician.

 Dirty air filter: This is a great problem to discover as it is very easy to fix. You may not have realized exactly how important it is to change your air filter on a regular schedule.

 It’s the most important part of regular AC maintenance.

 Many people don’t know how frequently it needs to be changed or the serious problems a dirty filter can cause. A dirty or clogged filter really can shut your entire HVAC system.

 If your air filter looks dirty, change it. That alone may be the only fix your air conditioner needs to begin blowing cool air again! 

 While the indoor component of your cooling system contains the fan that blows air through your home, it will blow air even when the outside unit is not working.

 It is your outside unit (the condenser) that turns the air cool that gets circulated through your home.

 If you’ve tried the above 3 troubleshooting AC steps and your vents are still blowing warm air, it’s time to go outside. 

 Look at the outdoor AC unit. Does it have any frost or ice on it? If it does, change the setting on your thermostat from COOL to having only the FAN on.

 This will allow the unit to thaw. It may take as much as 12 hours for the unit thaw out.

 A frozen outdoor AC unit is often an indicator that your air filter needs to be changed.

 If changing your filter fixes the problem, but only temporarily, you may be dealing with a possible freon leak.

 Contact us and our technicians will quickly come out to resolve any potentially dangerous freon leak. We will also refill your unit with refrigerant. Another thing to check is whether the unit is dirty.

It’s common, especially here in Kansas, to find our outdoor AC unit covered with milkweed, leaves or other natural debris.

 If you can see it is dirty, you can clean it.

 How to Clean Your AC Condenser Unit Turn off your condenser unit. Remove the top section and outer caging.

 Spray the coils from inside the condenser with a hose. Make sure you are spraying from the inside going out.

 Do not spray from the outside in.

Also, take care to not bend the fins.

 If you want a professional to handle the cleaning and maintenance of your AC unit, feel free to schedule service with us online or by calling at (416)402-8295 Other Broken AC Problems If none of the above AC Blowing Warm Air Troubleshooting Steps worked for you, call us. 

We may be able to provide you more things to check that can be handled on your own.

The first step in troubleshooting is to ask the owner/user or operator about the problem, then inspect, check and test the system using troubleshooting instrument. 

Your ability to think the problem of a cooling system is a great asset in troubleshooting. Your five (5) senses can tell a lot about what is going on a system.

 Look: for vibration, gauge reading, current and voltage reading, leaks, broken or loose parts. Listen: for compression knocks, valves opening or closing, switches clicking at the right time. Feel: feel temperature changes, pipes that are hot when they should be cool, or vice versa. Smell: for burned wire insulation, hot parts or belts slipping. 

Taste: for food that has spoiled due to vacuum temperatures. Owner’s Description of Problem • The first column of the troubleshooting chart normally lists the problem.

 This column would be the complaint given to the service technician by the owner – usually in general terms. • The technician logins troubleshooting by carefully listening to the owner’s complaint. Checking Possible Cause • The next step would be for the technician to check the possible cause column & to analyze this listing in terms of the major components of the system. • After a thorough investigation of the possible cause’s column, the technician proceeds to identify the parts of the system listed as the possible cause of the problem or symptom. The technician should then be able to determine a specific cause or malfunction & to identify the specific faulty part. Suggested Remedy • The final column on the troubleshooting chart may have a heading of remedy. This is the third (3rd) step when using troubleshooting chart. The technician will perform the appropriate task for this column. The actual procedure will vary depending upon the specific remedy selected, the type of part or device being checked & the specific system. Basic service & safety procedures are always followed as the technician repairs the system. Troubleshooting Chart • Servicing must always accomplish through the use of the proper tools, gauges, electrical analyzing equipment & other necessary equipment. • The use of troubleshooting charts is relatively simple. The technician must understand it is a helpful map which leads from step 1 – Problem, step 2 – Possible Cause, & step 3 – Remedy. • One must be very careful to utilize the specific troubleshooting chart the manufacturer of the equipment being serviced. Troubleshooting charts vary, depending upon the purpose of the equipment & the particular manufacturer. The troubleshooting chart is broken down into the basic columns; Complaints, Possible Cause & Repair. COMPLAINT POSSIBLE CAUSE REPAIR A. Compressor will not 1. Line disconnect switch 1. Close start or disconnect start – no hum open. switch. 2. Fuse removed or blown 2. Replace fuse. B. Compressor will not 3. Overload protector tripped 3. Refer to electrical diagram. start – hums 4. Control stuck in open 4. Repair or replace control. 5. Relocate control. position. 6. Check wiring against 5. Control off due to cold diagram. location. 6. Wiring improper or loose. 1. Check wiring against 1. Improperly wired. diagram. 2. Low voltage to unit. 2. Determine reason and correct. 3. Starting capacitor defective. 3. Determine reason and replace. 4. Relay failing to close. 5. Compressor motor has 4. Determine reason and correct, replace if winding open or shorted. necessary. 6. Internal mechanical trouble 5. Replace compressor. in compressor. 6. Replace compressor. C. Compressor will not 1. Improperly wired 1. Check wiring against start – hums but 2. Low voltage to unit. diagram. trips on overload 3. Relay failing to open. protector. 2. Determine reason & correct. 4. Run capacitor defective. 3. Determine reason & correct, D. Compressor starts 5. Excessively high discharge and runs, but short replace if necessary. cycles on overload pressure. 4. Determine reason & replace projectors. 6. Compressor motor has a 5. Check discharge shutoff, winding open or shorted. possible overcharge. 7. Internal mechanical trouble 6. Replace compressor. in compressor (tight). 7. Replace compressor. 1. Additional current through 1. Check wiring diagram, check overload protector. for added fan motors, pumps, etc., connected to 2. Low voltage to unit. wrong side of protector. 2. Determine reason and 3. Overload protector correct. defective. 3. Check current, replace protector. 4. Run capacitor defective. 4. Determine reason and replace 5. Excessive discharge 5. Check ventilation, restriction pressure. in cooling medium, restriction in refrigeration system. 6. Check for possibility of 6. Suction pressure too high. misapplication, use stronger unit 7. Compressor too hot – return 7. Check refrigerant charge (fix gas hot. leak), add if necessary. 8. Compressor motor has a 8. Replace compressor. winding shorted. E. Unit runs ok, but 1. Overload protector 1. See D short cycles. 2. Thermostat 2. Differential set too close – 3. High pressure cut-out due widen. to: a. Insufficient air. 3a. Check air to condenser –correct. b. Overcharge. 3b. Reduce refrigerant charge. c. Air in system 3c. Purge 4. Low pressure cut-out due to: a. Undercharge 4a. Fix leak, add refrigerant. b. Restriction in 4b. Replace device expansion device. Quiz 1: TRUE OR FALSE: Write TRUE if the statement is true and FALSE if the statement is false 1. When responding to service call the technician must always approach the problem in a logical sequence. 2. The first column of the troubleshooting chart normally lists the problem. This column would be the complaint given to the service technician by the owner – usually in general terms. Static electricity 3. After a thorough investigation of the possible cause’s, the technician proceeds to identify the parts of the system listed as the possible cause of the problem or symptom. 4. The use of troubleshooting charts is relatively simple. The technician must understand it is a helpful map which leads from step 1 – Problem, step 2 – Possible Cause, & step 3 – Remedy. 5. The technician logins troubleshooting by carefully listening to the owner’s complaint. TITLE Planning and preparing for troubleshooting and repairing OBJECTIVES INTRODUCTION In this lesson you will be able identify and understand how the seven basic refrigeration components function TOPIC 2 Parts of Refrigeration Circuit Lesson 1 Seven Basic Refrigeration Components SEVEN BASIC REFRIGERATION COMPONENTS 1. Motor Compressor 2. Condenser 3. Refrigerant flow Control/Metering Device 4. Evaporator 5. Discharge Line 6. Liquid Line 7. Suction Line 1. Compressor A compressor acts as the “heart” of a refrigerant-based mechanical cooling system. Its functions include drawing in the cool vaporized refrigerant that carries the heat energy from the evaporator coils, compressing it from a low pressure and temperature to a high pressure and temperature, and pushing it around the refrigeration loop for the purpose of heat rejection. a visual representation of a motor compressor for Air conditioning (left) and refrigeration unit (right) a visual representation of a cut-away view and operation of compressor 2. Condenser Refrigeration in real sense is simply moving heat from a place where it is not wanted to a place where it is not objectionable. The condenser is a device used for removing heat from the refrigeration system. It is a component which transfers the heat from the refrigeration system to a medium which has lower temperature than refrigerant present in condensers; it can absorb and move heat to an ultimate disposal point. The condenser is the door opening provided to transfer unwanted heat out of the refrigeration system. Air and water are the two-basic media in which condensers could reject their heats. These two are selected because they are usually available in sufficient quantities and are cheap. They are also easy to handle and are not dangerous. Their normal temperature range is also satisfactory for liquification of refrigerant. a visual representation of fin coil type condenser 3. Refrigerant Flow Control/Metering Device Refrigerant flow control is used to fine-tune the temperature in refrigerant devices by maintaining an optimal flow of refrigerant into its evaporator. Refrigerant flow control technology is used in everything from air conditioners to refrigerators in order to keep stable, cooled temperatures in closed areas a visual representation of capillary tube (left) and thermostatic expansion valve (right) 4. Evaporator The evaporator is that part of the low-pressure side of the refrigeration system in which the liquid refrigerant boils or evaporates, absorbing heat as it changes into a vapor. It accomplishes the actual purpose of the system, refrigeration. a visual representation of evaporator for refrigeration unit CONNECTING PIPELINES IN REFRIGERANT CIRCUIT 5. Suction Line The suction line is the part of the piping system of an ac/ref unit. After the refrigerant evaporates into a gas in the evaporator coil the section of piping from this coil to the compressor is called the suction line. The suction line caries the refrigerant vapor from the evaporator to the compressor. The line must be large enough to carry the vaporized refrigerant with minimal flow resistance. 6. Discharge Line Discharge gas lines (often referred to as hot gas lines) allow refrigerant to flow from the discharge of the compressor to the inlet of the condenser. 7. Liquid Line This is the pipe connecting the outlet of condenser and inlet of metering device. Lesson 2 Operation of Window-Type Air-Conditioning Unit Air conditioning unit is a control system for temperature, humidity, air movement and air cleaning in a confined space. The unit can control the temperature by absorbing the heat inside the room. How does it happen? First, to fully understand how window-type air-conditioning system works, we need to learn some thermal laws related to refrigeration and air-conditioning: 1. Fluids absorb heat while changing from a liquid state to a vapor state and give up heat in changing from a vapor to liquid. 2. Heat flows only from a body which is at a higher temperature to a body which is at a lower temperature (hot to cold) These laws will help us fully understand the operation of the window-type air conditioning system. Now we can start to discuss the operation of window-type air-conditioning. As we set the unit to fan mode, we are supplying power to the fan motor. The movement of the fan motor will suck air from the air filter side blowing it out to the evaporator side (compressor is still off therefore no movement on refrigerant line). This process circulates the air from the room and filters it. The thermostat is a thermal sensor which can be set. Once the temperature of the evaporator varies, and the setting of the thermostat becomes the same with the temperature, it automatically turns off the compressor (provided that the compressor is running) then turns it on again when the temperature becomes warmer. As we set the unit into cool mode, we are energizing the motor compressor. The compressor will force the refrigerant to circulate through the system. The refrigerant will flow from discharge line, passing through the condenser, to the metering device, then going to the evaporator and returning to the suction line of the compressor. This completes the cycle. So how is heat absorbed? Warm filtered air passing to the evaporator side then returning to the room a visual representation of an operation of window-type air-conditioning unit The refrigerant from the discharge line is a high-pressure vapor. And we know that high pressure vapor is directly proportional to temperature making the temperature in the condenser hot. The air which had been suck by the condenser fan from outside of the room is a little bit lower compared to the temperature of the condenser. This will now cool down the temperature of the refrigerant in the condenser as stated in law number two (2); Heat flows only from a body which is at a higher temperature to a body which is at a lower temperature (hot to cold). As the condenser gives off heat to the surrounding medium, the refrigerant changes state from gas to liquid but still it is high temperature high pressure liquid as stated in law number one (1); Fluids absorb heat while changing from a liquid state to a vapor state and give up heat in changing from a vapor to liquid. The liquid will now pass through the metering device where pressure will drop through its throttling effect. Again, as we know, if the pressure decreases, temperature also decreases. As a result, the refrigerant absorbs heat (air coming from the room sucked by the evaporator fan) from room. When the refrigerant absorbs heat, it boils and changes its state from liquid to vapor as stated in law number (1); Fluids absorb heat while changing from a liquid state to a vapor state and give up heat in changing from a vapor to liquid. As low temperature low pressure vapor travels down the suction line it continues to absorb heat turning it to superheated refrigerant. When the refrigerant enters the suction line and passing to the compressor, it becomes more superheated. It continues to be superheated until such time that it reaches the first coil of condenser. This cycle keeps on repeating until desired temperature of the room is achieved Quiz 1: MULTIPLE CHOICE: Identify the correct word/s on the following statement. Encircle the letter of the correct answer. 1. I t acts as the “heart” of a refrigerant-based mechanical cooling system. A. Condenser B. Evaporator C. Motor Compressor D. Refrigerant Flow Control/ Metering Device 2. Is a device used for removing heat from the refrigeration system. A. Condenser B. Evaporator C. Motor Compressor D. Refrigerant Flow Control/ Metering Device 3. It is used to fine-tune the temperature in refrigerant devices by maintaining an optimal flow of refrigerant into its evaporator A. Condenser B. Evaporator C. Motor Compressor D. Refrigerant Flow Control/ Metering Device 4. It is the part of the low-pressure side of the refrigeration system in which the liquid refrigerant boils or evaporates, absorbing heat as it changes into a vapor A. Condenser B. Evaporator C. Motor Compressor D. Refrigerant Flow Control/ Metering Device 5. It is a gas lines (often referred to as hot gas lines) allow refrigerant to flow from the discharge of the compressor to the inlet of the condenser. A. Discharge Line B. Extension Line C. Liquid Line D. Suction Line Answer Key: Multiple Choice 1. C. 2. A. 3. D. 4. B. 5. A. TITLE Planning and preparing for troubleshooting and repairing OBJECTIVES In this lesson you will be able to identify and interpret manufacturers INTRODUCTION name plate. Nameplates provide useful information about equipment. Among other TOPIC 3 things, the information can be used to understand energy use, find Lesson 1 compatible or more efficient replacements for equipment and General Information: troubleshoot problems. This fact sheet provides details about types of information found on nameplates. Manufacturers Nameplate Overview Basic Nameplate Information Most equipment nameplates will have some common items of information. Many of these are self- explanatory, and include: • Manufacturer • Manufacturer’s address • Model number • Serial number • Certification mark(s) This general information can be useful in finding out more details about particular through the manufacturers published information. Various certification marks are shown below. AIR CONDITIONING MANUFACTURER’S NAMEPLATE a visual representation of air-conditioning (left) and refrigeration (right) nameplate To begin, we have the model number. This is usually printed on a label on the system, which is often located on the inside of the access panel or it will be on the inside or outside wall of the unit. Frequently, this will also be where the serial number will be located. The model number usually indicates the heating or cooling capacity, but on newer systems the cooling capacity can also be stated separately. The model number will indicate the tonnage of the air conditioning or heat pump system. Tonnage is a unit of measure that is used to describe the cooling or heating capacity of a system. A ton of cooling is based upon how much heat is needed to melt one ton (which is 2000 lbs.) of ice in 24 hours. A ton of cooling equals 12,000 BTU/hour. BTU is short for British Thermal Unit. For example, if a system is 30,000 BTU/hour, it is said to be a 2.5-ton system. Within the model number, there will be a number that is divisible by 12. That number will determine allow you to determine the tonnage of the system. If you see the number 30 in the model number, that will tell you that your system is 2.5 tons. If you have a newer system, the cooling capacity will generally be indicated directly on the nameplate. Usually, the nameplate will be located on a sticker on the outside or inside of the unit. Also, frequently listed on the nameplate is the voltage. The voltage indicates how much electricity the system uses. The voltage of a system will remain constant regardless of the load that is placed on it. However, as more of a load is placed on the system, the current will increase. As a result, the number of watts used will increase. Additionally, you may also see how many phases your system is. For most residential applications, it will be single phase. Another important piece of information on the nameplate will be the Rated Load Amperage, often times labeled as RLA. This is a calculation that is used to get approval by the Underwriters Laboratories for a compressor motor. You will also see the Full Load Amperage, often labeled as FLA. With an increase in load on a motor, the total amperage needed to power the motor increases. When the full load of the motor is reached, the total amperage that the motor is drawing at this point is the full load amperage, or FLA. This is a value that is used in order to size field wires and fuses. Next, the serial number, which is usually located on the nameplate, can tell you some important information as well. While this may look like a long string of numbers and letters that do not mean anything, they sometimes can tell you the age of your system. The serial number of a unit means different things on different systems. In general, the serial number will tell you the age of your system. Another common and important piece of information on your system is its Energy Efficiency Ratio. This information tells you how much electricity you use to obtain a certain amount of cooling. The unit of measure for this is KW per hour of electricity used/1,000 BTU’s. You will usually be able to find this information on an Energy Guide sticker that is bright yellow and often located on the side of the system. This sticker will tell you your estimated yearly operating cost as well. Refrigerant name and quantity are the type of refrigerant and the amount of refrigerant charged in the system. The easiest way to establish the amount of refrigerant in the system is to use data supplied by the manufacturer: • Many refrigeration systems, especially small ones, have a Name Plate showing the amount of refrigerant. • Alternatively, you may have a record of the amount of refrigerant in the documentation supplied when the system was installed. On a Name Plate there will be a refrigerant name (which will enable you to establish whether the refrigerant is a HCFC, HFC and also a refrigerant charge, shown in grams or kilograms. The name plate shows the type of data you are likely to find. Half way down the right side of the label (inside the oval) it shows the refrigerant used is R-22 and the quantity is 893 grams. Quiz 1: Enumeration: List down at least 5 information you can find in an air conditioning nameplate. 1. Brand Name 2. Model Number 3. Serial Number 4. Manufacturer’s Address 5. Full Load Ampere (FLA) 6. Energy Efficiency Ratio (EER) 7. Type and amount of refrigerant charged WEB SCRIPT HVAC Sector: Qualification: RAC Servicing (DomRAC) NC II Unit of Competency: Troubleshoot and Repair Domestic Refrigeration and Air-Conditioning (DomRAC) Systems Module Title: Troubleshooting and Repairing Domestic Refrigeration and Air- Learning Outcomes: Conditioning (DomRAC) Systems Developer/s: LO2: Identify and Repair Faults/Troubles Alvin P. Saulon TITLE Planning and preparing for troubleshooting and repairing OBJECTIVES In this lesson you will be able to troubleshoot and repair electrical parts, INTRODUCTION components of DomRAC units. Some AC electrical problems can arise solely from broken electrical parts and faults in the wiring that services it. These are some of the common parts and problems that lead to electrical failure. TOPIC 1 Electrical parts, components troubleshooting and repairing Lesson 1 Issues with electrical parts Loose Wire Within your air conditioner itself, there are many electrical parts that bring power to different parts of the unit. If any of these wires come loose over time or with excess wear, it can disrupt power flow to those parts. Wrong Fuse If you’ve already self-repaired, or had your AC electrical system serviced by someone other than a professional, you might now have incorrect replacement parts in your unit. This includes the wrong type or size fuse/circuit breaker for your specific HVAC system. Dirty Fuse Just like filters need to be cleaned to allow the flow of air, fuses need to be kept clean to allow the flow of electricity. If your unit hasn’t been properly maintained, debris can block the connection between fuses. Bad Capacitor The capacitor is an essential part of the AC electrical system. It stores charges and regulates the power to the system. If the capacitor is failing, you could experience recurring AC electrical problems. Short in Wiring When wires receive more electricity than they were designed to handle, they can short out. This can happen due to a power outage in a storm, or the wires could weaken over time. This blocks the flow of electricity and causes a fire hazard. Electric bill suddenly goes up You might be tipped off to any of the above problems if your electric bill suddenly skyrockets. AC electrical usage can comprise a significant portion of your regular electric bill, so if your air conditioner suddenly runs more often or uses more energy than before, than you will see that change reflected in your bill. Keep track of significant changes and be aware of AC electrical problems before they lead to breakdowns. AC Won’t Turn Off If your air conditioner is constantly running and struggling to reach a desired temperature, it might not be electrical damage at all. Buildings that skimp on AC maintenance are likely to develop symptoms that resemble AC electrical problems. An accumulation of dust and grime in your filter can make your AC struggle to keep cool and run constantly. This could lead to frozen coils, so keep up your regular maintenance. Common Troubles of Compressor Motor Connections Compressor motor fails to start… A) No humming. 1. No power 2. Open overload protector 3. Open running winding 4. Loose connections 5. Open coil of current relay B). With humming. 1. Low voltage  10% of power supply 2. Shunted winding 3. Open starting winding 4. Grounded winding 5. Tight/stuck-up compressor 6. Defective starting capacitor 7. Defective running capacitor 8. Defective starting relay (open contact) 9. Loose connection C) Start and run by cycles on Overload Protector. 1. Low voltage: 10% of power supply 2. Relay does not get-off starting winding 3. Weak overload protector 4. Additional current flowing in overload protector 5. Shunted winding 6. Tight compressor 7. Grounded windings 8. Defective capacitor Task Sheet 1: Checking Electrical Windings and Test Run Motor Compressor Given a qualification, you should be able to check condition of Performance compressor electrical windings. Objective: Supplies/Materials: Paper, Marker, Masking tape, Gloves, Goggles, Clean rag Equipment/Tools: Analog/Digital Ohmmeter, DomRAC unit Screwdrivers, Longnose plier Steps/Procedure: 1. Switch OFF the unit and unplug from power source Note: Do not remove the power plug by pulling by the cord. a visual representation of unplugging from power source 2. Disconnect the wiring connection of compressor motor. a visual representation of disconnecting wiring connection 3. Check for resistance and continuity • Set the multimeter to Rx1 and calibrate the meter through zero ohm adjust knob for analog tester • Set digital multi meter to resistance Ω. a visual representation of calibrating voltmeter 4. Put label/tag on terminal of compressor using masking tape. 1 23 a visual representation of tagging/labelling motor compressor terminal 5. Record the resistance reading obtained from the different terminals. Using the formula: S + R terminals = highest reading C + S terminals = second highest C + R terminals = lowest reading TERMINAL RESISTANCE 2&3 20 Ω 1&2 15 Ω 1&3 10 Ω a visual representation of CSIR electrical connection Based on the resistance Terminal 1 = Common (C) Terminal 2 = Starting (S) Terminal 3 = Running (R) Note: If the resistance reading did not conform to the formula, compressor motor winding is defective. 6. Set the ohmmeter to Rx10K. calibrate the meter to zero and place the test prod to common terminal and compressor body. Note: If the pointer deflects, the compressor is grounded. If the pointer did not deflect, the compressor winding is not grounded (good). a visual representation of checking motor compressor for grounding defect 7. Observe the following data of winding resistance to indicate possible compressor troubles. 8. Proceed to test run motor compressor using the wiring diagram below. a visual representation of PSC wiring connection M L S a visual representation of CSIR wiring connection 1. Have your instructor check your work. 2. Perform housekeeping. Performance Criteria Checklist CRITERIA YES NO Did you …? 1. Switch OFF the unit and unplug from power source? 2. Disconnect the wiring connection of compressor motor? 3. Put label/tag on terminal of compressor using masking tape? 4. Record the resistance reading obtained from the different terminals? 5. Identify compressor motor terminal correctly? 6. Check compressor winding for grounding? 7. Test run motor compressor using PSC and CSIR connection? 8. Did you perform housekeeping? Trainer’s Signature: Comment/Feedback: Task Sheet 2: Identify Terminal Leads Using an Ohm Meter and Test Run a 3-Speed Fan Motor Performance Given a qualification, you should be able to identify and test run fan Objective: motor Supplies/Materials: Paper, Marker, Masking tape, Gloves, Goggles, Clean rag Equipment: Analog/Digital Ohmmeter, AC Unit, Fan motor Steps/Procedure: Terminal leads of fan motors are identified by color-coding and by the resistances of the windings. The colors of the terminal leads may fade, making them hard to identify. The terminal leads may have to be identified by the resistances of the windings. 1. Switch OFF the unit and unplug from power source Note: Do not remove the power plug by pulling by the cord. a visual representation of unplugging from power source 2. Disconnect the wiring connection of fan motor. a visual representation of disconnecting the wiring connection of fan motor 3. Check for resistance and continuity • Set the multimeter to Rx1 and calibrate the meter through zero ohm adjust knob for analog tester • Set digital multi meter to resistance Ω. a visual representation of calibrating voltmeter 4. Label the terminal leads from 1 to 5 as shown below. Use masking tape. a visual representation of tagging/labelling fan motor terminal 5. Make a table like the one below to record the resistances of the different terminal lead combinations. TERMINAL RESISTANCE RANK S (OHMS) 1 1&2 2 1&3 3 1&4 4 1&5 5 2&3 6 2&4 7 2&5 8 3&4 9 3&5 10 4 & 5 6. Measure and record the resistances of the different terminal lead. Use the table prepared in Step 5. 7. Rank the readings from highest to lowest, making the highest reading as rank 1 and the lowest as rank. 10. a visual representation of windings of a 3-speed fan motor Characteristics of the Windings Terminal: A and C - highest resistance A and L - second to the highest H and M - is equal to M and L C and H - higher than H and M or M and L 8. The terminal lead found both on the highest (Rank 1) and second highest resistance (Rank 2) is the auxiliary terminal lead . NOTE: If there is no terminal lead found on both the highest and second highest resistance, check the values by measuring the resistance of the terminal leads again. a. With the auxiliary terminal lead now identified, the other terminal lead on the highest reading (Rank I) is the COMMON terminal lead. b. The other terminal lead on the second to the highest reading (Rank 2) is the LOW terminal lead. 9. Using the LOW terminal lead now as the reference terminal, measure the resistance of the two remaining terminal leads. a. The one with the higher resistance is the HIGH terminal lead. b. The other unidentified terminal is the MEDIUM terminal lead. 10. Using now the LOW terminal lead as the reference point, measure the resistance of the other terminal leads. NOTE: If the terminal leads are identified correctly, they must follow the table below. Terminals L and A - highest resistance L and C - second highest resistance L and H - second lowest resistance L and M - lowest resistance NOTE: If the readings of the resistances do not follow the pattern above, repeat identifying the terminal leads. 11. After terminal leads of fan motor identified, perform test run fan motor using the diagram below a visual representation of wiring connection of test run fan motor 12. Before energizing the circuit check the resistance on the plug. Resistance (Ω) reading should follow the table below. SELECTOR SWITCH RESISTANCE READING POSITION No Resistance/Continuity reading OFF Either highest/second highest Ω FAN reading it depends on the manufacturer setting LOW COOL Highest Ω reading MEDIUM COOL Second highest Ω reading HIGH COOL Lowest Ω reading Note: a. If the reading of the resistance is diff. from the guide on the table check your connection. b. If the connection of the Starting and Common terminal of fan motor was interchange the rotation of the motor will also reverse. 13. Have your instructor check your work. 14. Perform housekeeping

Performance Criteria Checklist CRITERIA YES NO Did you …? 1. Switch OFF the unit and unplug from power source? 2. Disconnect the wiring connection of fan motor? 3. Put label/tag on terminal of fan motor using masking tape? 4. Record the resistance reading obtained from the different terminals? 5. Rank the readings from highest to lowest, making the highest reading as rank 1 and the lowest as rank. 10? 6. Identify the Starting and Common terminal from the highest and second highest rank? 7. Use the LOW terminal lead as the reference terminal, to measure the resistance of the two remaining terminal leads? 8. Perform test run fan motor using the given wiring diagram? 9. Check the resistance reading on the plug before energizing? Trainer’s Signature: Comment/Feedback: TITLE Identify and repair faults/troubles OBJECTIVES In this lesson you will be able to troubleshoot and repair mechanical INTRODUCTION parts, components of DomRAC system. The main concept and procedures of each operation is the same for all refrigeration and air-conditioning systems. They differ only in each system specific connectivity requirements or tools to be used. TOPIC 2 Mechanical parts, components troubleshooting and repairing Lesson 1 overview Mechanical parts, components troubleshooting and repairing overview Most of servicing and troubleshooting activities to RAC systems –dealing with refrigerants – falls within the one of the following main operations: ▪ Recovery of Refrigerant (will be discuss in the next Learning outcome) ▪ Flushing ▪ Nitrogen charging (OFDN)/Leak Detection ▪ Evacuation ▪ Charging What is flushing? Flushing is performed in order to remove all contamination (dirt) from the system. The smallest particle of contamination cause restriction and problems for a good function of the replaced compressor. It takes less than 1/10 of a teaspoon of debris (dirt) to completely restrict flow of refrigerant and oil in the typical auto AC system. Cleanliness and proper flushing procedures are very important Why / When flushing? The AC compressor is the only moving part in the entire system and the only reason for oil in the system. The oil is being circulated throughout the system, that means that all the components (condenser, hoses, tubes, evaporator, drier, accumulator) have some coating of oil internally. If any dirt, debris or contamination happened in the system all components are affected. Removing the oil (and oil film inside the components) will eliminate all of the contamination from the AC system. It’s the oil that attracts and holds contaminants within the system. Remove the old oil = remove the contamination. Nitrogen charging (OFDN)/Leak Detection RAC systems are designed to operate adequately with a fixed charge of refrigerant. If it has been determined that a system has insufficient refrigerant, the system must be checked for leaks, then repaired and recharged. If no refrigerant was found in the system. a visual representation of a nitrogen cylinder tank with pressure regulator EVACUATION A refrigerating system must contain only the refrigerant in liquid or vapor state along with dry oil. All other vapors, gases, and fluids must be removed. Connecting the system to a vacuum pump and allowing the pump to run continuously for some time while a deep vacuum is drawn on the system can best remove these substances. It is sometimes necessary to warm the parts to around +50°C while under a high vacuum; in order to accelerate the removal of all unwanted moisture, heat the parts using warm air, heat lamps, or water. Never use a brazing torch. If any part of the system is below 0°C, the moisture may freeze and it will take a considerably longer time for the ice to sublimate to vapor during the evacuation process. The equipment necessary to carry out the evacuation is: • vacuum pump • manifold gauges two servicing valves (in the case system is not equipped with servicing valves) • vacuum gauge. CHARGING System charging is adding the proper quantity of refrigerant to refrigeration system so that it operates as intended. For a given set of conditions (design conditions) systems have an “optimum” charge – this is the mass of refrigerant that the highest efficiency and design cooling capacity (or heating capacity, in the case of a heat pump) will be achieved. At off-design conditions, for example, at a higher or lower ambient temperature, the optimum charge will be different. However, it is best to add the specified charge since this is what the system has been designed to handle. a visual representation of a vapor refrigerant charging a visual representation of a liquid refrigerant charging Common Issues with AC System 1. Undercharge 2. Overcharge 3. Non - Condensable in system 4. Restricted metering device 5. Dirty or restricted air flow over condenser 6. Restricted air flow over evaporator Job Sheet: System Reprocess Performance Objective: Given a qualification, you should be able to perform system reprocess Paper, Marker, Masking tape, Gloves, Goggles, Clean rag, Lubricants Supplies/Materials: Refrigerants, Gasses, Electrical Controls, Abrasives, Manuals Equipment/tools: Flaring tool, Swaging tool, Tube cutter, Tube bender, set of pliers, set of Steps/Procedure: screw drivers, Types of wrenches, Vise grip, Hack saw, Linear Measuring Instrument, Pinch off tool, Vacuum pump motor Recovery/ Recycling unit, Oxy- Acetylene welding w/ complete outfit Refrigerator, Window type aircon, Gauge manifold w/ hoses, Electronic leak detector, Thermometer I. Pressure Leak test The system should be tightness tested (i.e., “leak tested”). This can be done by pressurizing the system with oxygen free, dry nitrogen (OFDN). Shut off the supply of nitrogen and check the pressure over a period of time (a minimum of 15 minutes, but it depends upon the size of the system; a larger system requires more time). Keep checking the pressure gauge to see if the pressure reduces. 1. Connect low pressure gauge port to the system's low side service port. 2. Connect center hose of the manifold gauge set to the nitrogen cylinder's pressure regulator port. 3. Open the nitrogen cylinder valve. 4. Open (turn clockwise) nitrogen pressure regulator until pressure reaches 150 psi. 5. Then open low side valve at manifold gauge set to transfer nitrogen into the refrigeration system up to 150 psi. 6. Close low pressure valve at the manifold gauge set when it reaches 150 psi. 7. Isolate the system by closing the nitrogen pressure regulator first and by closing the valve at the top of nitrogen tank. 8. Disconnect the center hose (Yellow) and release the pressure slowly. 9. Observe the pressure gauge at manifold gauge set. If leak exists, pressure will drop. Note: A minimum of 15 minutes, but it depends upon the size of the system; a larger system requires more time. Keep checking the pressure gauge to see if the pressure reduces. Take note of the following: Leak Test Psig Time Start: Psig Time Finish: 10. Apply soap and bubbles to joints and fitting connection while observing the pressure. Note: If the pressure does fall, it is likely that the system has a leak, so leak searching and repair procedures must be carried out. 11. When the system is confirmed to be leak-tight, release the OFDN in controlled manner. II. Perform Evacuation To evacuate and dehydrate a system, before filling with refrigerant, take the following steps: a visual representation of system evacuation/dehydration 1. Check vacuum pump oil level. 2. Connect low pressure gauge port to the system's low side service port. 3. Connect the high-pressure gauge port to the system's high side service port. (If available) 4. Connect center port at the manifold gauge set to the vacuum pump. 5. Open the low-pressure valve at manifold gauge set. 6. Open high-pressure valve at manifold gauge set. (If connected to the system) 7. Open the vacuum pump valve 8. Plug to a power source and turn on vacuum pump and wait. 9. When satisfactory vacuum has been reached (29-30” Hg or 500-1000 microns) close valve and turn off the pump and leave it for an appropriate length of time (15-30 mins for a small hermetic system, to several hours for a large site-installed system) to see if the vacuum gauge indicates an increase in internal pressure. Record the pressure and time start of observation. Evacuation Time Start: Psig Time Finish: Psig Note: If the pressure rises there could be two reasons for it: either there is a leak or moisture still in the system. In this case, the evacuation procedure should continue, but if a constant vacuum pressure is never achieved, then it is likely that a leak is present and the tightness test should be repeated. 10. If the vacuum pressure remains constant over a period of time, the circuit is correctly evacuated; dry and free of leakage. Record the pressure and time finish of observation Evacuation Time Start: Psig Time Finish: Psig 11. Close low pressure and high-pressure valve at manifold gauge and removes the vacuum pump. III. Charging Refrigerant 1. Turn on and set weight scale to zero. 2. Weigh and record the initial weight of refrigerant cylinder. Note: The amount of refrigerant based on manufacturers nameplate must be obtained and will be deducted from the initial weight of refrigerant cylinder. Tank Weight Before grams After grams 3. Connect center hose at manifold gauge set to the refrigerant cylinder. 4. Open output valve at the refrigerant cylinder. 5. Purge the hose with small amount of refrigerant. 6. Open low-pressure valve at manifold gauge set to allow the refrigerant transfer to the refrigeration system by the pressure inside the refrigerant cylinder. Note: Amount of refrigerant based on nameplate can be charged into the system. 7. Switch on the DomRAC unit to allow the refrigerant transferred to the refrigeration system by using suction force from compressor until desired refrigerant weight is achieved. 8. After 30-60 minutes of running observe and record all operating parameters. (Operating parameters is will be discussed on the last learning outcome of this module) 9. Close output valve at refrigerant cylinder. 10. To avoid venting of refrigerant to the atmosphere, open the low side valve at manifold gauge set until the remaining refrigerant on the center hose (Yellow) is transferred inside the system. Observe the low side gauge. 11. Disconnect hose all connection. 12. Weigh, record and put label using masking tape on the refrigerant cylinder. Tank Weight Before grams After grams Performance Criteria Checklist CRITERIA YES NO Did you …? 1. Connect all hoses correctly during leak test? 2. Set nitrogen pressure regulator to 150 psi before charging to the system? 3. Close all valves after charging nitrogen in the system? 4. Record the time and pressure of system during leak test? 5. Check vacuum pump oil level before using? 6. Connect all hoses and open all valves for evacuation? 7. Record the time, vacuum pressure and close vacuum pump valve after reaching 29”-30” Hg or 500-1000 microns? 8. Conduct observation on vacuum pressure for 15-30 minutes? 9. Weigh refrigerant cylinder before charging? 10. Purge center hose before charging refrigerant into the system? 11. Charge correct amount of refrigerant according to manufacturer’s nameplate and run the unit? 12. Collected DomRAC operating parameters after 30-60 mis of continuous running? 13. Perform housekeeping? Trainer’s Signature: Comment/Feedback: TITLE Identify and repair faults/troubles OBJECTIVES INTRODUCTION In this lesson you will be able to know the safety aspects on troubleshooting and repairing. TOPIC 2 Safety practices in performing troubleshooting and repairing Lesson 1 Safety Aspects 1. PPE is compulsory when handling and working with refrigerants. 2. Always ensure good ventilation while working on refrigeration systems. 3. Ensure that refrigerant cannot accumulate in low areas where they can cause fatal accidents. 4. Specific color-coding shall be followed for cylinders/containers of different refrigerants. 5. Pressure safety devices (i.e. pressure relief valves, safety pressure switches) shall be installed to prevent the equipment from operating over the maximum working pressure and must be calibrated. 6. A dual pressure-relief valve with changeover device shall be installed for larger systems to facilitate the repair/replacement without impairing system protection. 7. Appropriate safety precautions shall be observed for systems converted with hydrocarbon. 8. Proper protective caps shall be used on valves of refrigerant cylinders to prevent damage to valves that will cause refrigerant leaks. 9. Avoid contact with liquid refrigerants that can cause severe frostbite. 10. Hydrochloric and hydrofluoric acids may be present in contaminated recovered refrigerant and oils. Utmost care must be taken to prevent contact, even with oil spills when servicing contaminated equipment. 11. Recovered refrigeration oil should be properly stored for proper disposal. 12. Never exceed the cylinder’s safe liquid weight level based on net weight. Maximum capacity of any cylinder is 80% by maximum gross. 13. Appropriate wheeled device must be used to transport larger cylinders. Ensure that the cylinder is securely strapped when moving from one location to another. Never roll a cylinder on its side. 14. Good quality hoses/manifolds should always be used with seals/gaskets in place. 15. Never refill disposable cylinders. 16. Never braze or unbraze refrigeration piping system that has not been fully/properly evacuated of refrigerant for servicing and filled with inert gas (e.g. dry nitrogen). 17. Never use “halide torch method” (flame test) for leak testing to an unidentified refrigerant in a system. 18. Never use oxygen or compressed air for pressure or leak testing or when blowing-off piping to remove welding, brazing or cutting debris. 19. Avoid inhalation or exposure to refrigerant and lubricant vapor or mist. This will irritate skin, eyes, nose, and throat. 20. Never open refrigerant drums (for low pressure refrigerants) until it is cooled down to atmospheric pressure/temperature when replacing its cap with valves. 21. Electrical wirings should be kept away from contact with the system’s discharge line. This will damage the wire’s insulation that may cause short circuit. 22. All power supply should be disconnected and disabled to any equipment from which refrigerant is being recovered. 23. Never connect grounding wire to gas pipes, water pipes, telephone grounds, and lightning arresters. 24. Never use refrigerants without first understanding the associated MSDS. 25. Use tools with insulated handles that are in good condition when working with the system’s electrical lines. Quiz: TRUE OR FALSE Direction: Write TRUE if the statement is true and FALSE if the statement is false 1. PPE is compulsory when handling and working with refrigerants. 2. Pressure safety devices (i.e. pressure relief valves, safety pressure switches) shall be installed to prevent the equipment from operating over the maximum working pressure and must be calibrated. 3. Proper protective caps shall not be used on valves of refrigerant cylinders to prevent damage to valves that will cause refrigerant leaks. 4. Never exceed the cylinder’s safe liquid weight level based on net weight. Maximum capacity of any cylinder is 100% by maximum gross. 5. Always refill disposable cylinders. 6. Never use oxygen or compressed air for pressure or leak testing or when blowing-off piping to remove welding, brazing or cutting debris 7. Electrical wirings should be kept away from contact with the system’s discharge line. 8. Good quality hoses/manifolds should always be used with seals/gaskets in place. 9. Contact with liquid refrigerants do not cause severe frostbite. 10. Appropriate safety precautions shall be observed for systems converted with hydrocarbon. Answer Key: TRUE OR FALSE 1. TRUE 2. TRUE 3. FALSE 4. FALSE 5. FALSE 6. TRUE 7. TRUE 8. TRUE 9. FALSE 10. TRUE WEB SCRIPT HVAC Sector: Qualification: RAC Servicing (DomRAC) NC II Unit of Competency: Troubleshoot and Repair Domestic Refrigeration and Air-Conditioning Module Title: (DomRAC) Systems Troubleshooting and Repairing Domestic Refrigeration and Air- Learning Outcomes: Conditioning (DomRAC) Systems Developer/s: LO3: Perform Refrigerant Recovery/Recycling and Retrofitting/ Conversion on Domestic Refrigeration and Air-Conditioning Unit Alvin P. Saulon TITLE Perform refrigerant recovery/recycling and retrofitting/ conversion on domestic refrigeration OBJECTIVES In this lesson you will be able to know safety in handling refrigerant INTRODUCTION TOPIC 1 Safe handling of refrigerants Lesson 1 Refrigerants Refrigerants A refrigerant is a fluid (liquid and gas) which transfer heat away from one point to another. In a typical vapor compression system, the refrigerant changes phase. That is, it changes from a liquid to a gas when it absorbs heat and changes back to a liquid when it gives up heat. Most chemicals have the ability to change from a liquid to a gas, but only a few chemicals do so in a manner that makes them good refrigerants. a visual representation of different types of refrigerant Most refrigerants used today for vapor compression air conditioning are called Halocarbons and Hydrocarbons. Halocarbon (CFC, HCFC, HFC) is a hydrocarbon molecule containing one or more halogens. The halogen elements most commonly used in refrigerants are chlorine (CI) and fluorine (F). Refrigerants used in centrifugal chillers are halocarbons based on methane, ethane and propane molecules. a visual representation of a CFC refrigerant atom composition Hydrocarbon (HC) - chemical compounds consisting of one or more carbon atoms surrounded only by hydrogen atoms. These are not damaging to the ozone layer and have a minimal global- warming potential. A flammable compound a visual representation of a HC refrigerant atom composition Refrigerant Nomenclature—single component refrigerants have an “R-” designation of two or three numbers, which reflect its chemical composition. • The first digit (of a refrigerant with three numbers) is one unit lower than the number of carbon atoms, the first digit is omitted. • The second digit is one unit greater than the number of hydrogen atoms in molecule. • The third digit is equal to the number of fluorine atoms in the molecule. Lesson 2 Safety when handling and working with refrigerants 1. Color-coding for refrigerant cylinders should be maintained for new refrigerants (although there are concerns from some manufacturers regarding this). Refer to Table 1 for refrigerant cylinder color assignments. 2. Refrigerant manufacturer’s recommended procedures shall be followed when handling refrigerants. 3. Refrigerant containers/cylinders shall be stored in a cool place or under a roof to protect it from weather extremes, away from the risk of fire and direct sunlight. 4. Extra care shall be taken not to drop refrigerant containers/cylinders that may damage the container or its valve. 5. When not in use, container valves shall be closed, the valve outlet cover nut fitted, and the valve protection cover replaced. 6. While charging, refrigerant containers/cylinders shall not be connected to a system of higher pressure to prevent back flow of refrigerant to the container/cylinder. 7. Cylinders intended for a certain type of refrigerant shall not be filled with another type unless they are properly evacuated and labeled. 8. Strictly follow cylinder capacity when re-filling with refrigerants. 9. When re-filling with recovered refrigerants, only 70% of the maximum capacity in weight for a particular type of refrigerant should be filled to a cylinder (since it may contain oil with lower density). Overfilling can cause the cylinder to explode leading to fatal danger. 10. Calibrated weighing scale shall be used when filling a cylinder. 11. Leaks on refrigerant cylinder valves shall be checked and repaired before storing in a ventilated area and on a vertical position. 12. Establish proper leak testing routine on charging hoses and refrigerant handling equipment. 13. Thorough check-up of refrigerant cylinders shall be done first before refilling. 14. Defective refrigerant cylinders shall not be repaired and re-used. 15. Refrigerant cylinders shall conform to appropriate standards. 16. Storage tank relief valves shall be checked to ensure that they are not leaking (shall conform to relevant PNS). 17. Transfer pump seals of filling machines shall be regularly checked for leaks. 18. Charging lines shall be kept as short as possible and be fitted with either check valves or isolation valve near the end of charging lines. 19. Whenever possible, use quick disconnect fittings with one-way valve in transferring or working with refrigerants. 20. Use PPE, such as side shield glasses/goggles, gloves, jackets, and safety shoes when handling containers. 21. Never apply direct flame or live steam to a container or valve. 22. Never refill disposable cylinders. 23. Never use a lifting magnet or sling (rope or chain) when handling cylinders. 24. Never use cylinders for rollers, supports, or any purpose other than to contain the refrigerant. 25. Protect cylinders from any object that will result in a cut or other abrasion on the surface of the metal. 26. Never tamper, repair or alter the safety devices of the cylinders. 27. Never force connections that do not fit. 28. When in doubt of refrigerant type, use electronic refrigerant identifier (will be available in all Regional EMB offices and TESDA accredited training institutions nationwide) to analyze its composition. 29. Avoid skin contact with refrigerants as they may cause frostbite and other skin irritations. 30. Blended refrigerants should only be charged into a system in liquid state. Quiz: TRUE OR FALSE Direction: Write TRUE if the statement is true and FALSE if the statement is false 1. Color-coding for refrigerant cylinders should be maintained for new refrigerants (although there are concerns from some manufacturers regarding this). Refer to Table 1 for refrigerant cylinder color assignments. 2. Refrigerant containers/cylinders shall be stored in a cool place or under a roof to protect it from weather extremes, away from the risk of fire and direct sunlight. 3. Extra care shall be taken not to drop refrigerant containers/cylinders that may damage the container or its valve. 4. When not in use, container valves shall be open the valve outlet cover nut fitted, and the valve protection cover replaced. 5. Strictly follow cylinder capacity when re-filling with refrigerants. 6. When re-filling with recovered refrigerants, only 100% of the maximum capacity in weight for a particular type of refrigerant should be filled to a cylinder (since it may contain oil with lower density). Overfilling can cause the cylinder to explode leading to fatal danger. 7. Calibrated weighing scale shall be used when filling a cylinder. 8. Defective refrigerant cylinders can be repaired and re-used. 9. Storage tank relief valves shall be checked to ensure that they are not leaking (shall conform to relevant PNS). 10. Charging lines shall be kept as long as possible and be fitted with either check valves or isolation valve near the end of charging lines. 11. Use PPE, such as side shield glasses/goggles, gloves, jackets, and safety shoes when handling containers. 12. Always apply direct flame or live steam to a container or valve. 13. Never refill disposable cylinders. 14. Never use cylinders for rollers, supports, or any purpose other than to contain the refrigerant. 15. Never tamper, repair or alter the safety devices of the cylinders. Answer Key: TRUE OR FALSE 1. TRUE 2. TRUE 3. FALSE 4. FALSE 5. FALSE 6. TRUE 7. TRUE 8. TRUE 9. FALSE 10. TRUE TITLE Perform refrigerant recovery/recycling and retrofitting/ OBJECTIVES conversion on domestic refrigeration INTRODUCTION In this lesson you will be able to TOPIC 2 understand the importance of Lesson 1 recovery of refrigerant and perform optimum recovery of refrigerant according to RAC Code of Practice Recovery/recycling of refrigerants The Ozone issue Montreal and Kyoto Protocol The Ozone Issue and The Montreal Protocol The ozone layer is a thin veil of molecules in the stratosphere, located between troposphere and ionosphere, which is about 11 - 48 kilometers from the earth’s surface. It blocks most of the Ultraviolet B or UV-B range from reaching the earth’s surface. Harmful effect of the UV-B rays in humans include skin cancer, eye disorders, weakening of body’s immune system and damage to plants and aquatic organisms. The stratospheric ozone depletion became a worldwide issue upon the discovery of the Antarctic “ozone hole” in 1985. Scientific evidence confirms that ozone damaged are caused by manmade compounds containing chlorine and bromine-such as chlorofluorocarbons (CFCs) and halons released in the atmosphere. CFCs were considered as “miracle compounds” in the chemical industry, but later were identified as the leading cause of ozone depletion. These are widely used in the industry like refrigeration and air conditioning (household, commercial, stationary and mobile), foam production (building insulation, flexible and rigid) and tobacco expansion. This global problem which alerted the international community led to the adoption of the Montreal Protocol in September 1987 and was entered into force on January 1, 1989 by 73 countries including the Philippines and the EEC. As of 2012, there are197 parties where South Sudan is the newest member Kyoto Protocol The Kyoto Protocol is a pact agreed on by governments at the United Nations conference in Kyoto, Japan in 1997 to reduce the amount of greenhouse gases emitted by developed countries by 5.2 percent of 1990 levels during the five-year period 2008-2012. Eighty-four (84) countries have signed the pact and 40 have already ratified it, with Romania as the only country with emissions target who have ratified to date. It is the only legally-binding plan for combating global warming. Greenhouse gases are gases that trap heat in the earth’s atmosphere. What is NCPP Phase-out Plan? The Montreal Protocol on substances that deplete the ozone layer is an agreement among 129 countries, including the Philippines that limits the production, application and use of the most common ozone depleting substances, like CFCs and provides for the phase-out of these chemicals. Under the Montreal Protocol, the Philippines is committed to phase out the country’s CFC consumption by: National CFC Phase-Out Plan Year Percentage 2015 10% 2020 35% 2025 67.5% 2030 97.5% 2040 100% Environmental Laws for Recovery of Refrigerant Republic Act No. 6969 otherwise known as the “Toxic Substances and Hazardous and Nuclear Waste Control Act of 1990”. Its main objective is to monitor, regulate and keep an inventory of imported, manufactured, or used chemicals that presents unreasonable risk or injury to health or to environment in accordance with the national policies and international commitments. Republic Act No. 8749, known as the “Clean Air Act of 1999”, RA 8749 is intended to formulate a holistic national program on air pollution. DENR is the lead agency but cooperates with other government agencies as well as with industry and related non-governmental organizations. The Clean Air Act’s primary focus is on ambient air quality but it is applicable to all other pollutants including ODS How refrigerants affect ozone layer and global warming Some refrigerants, especially chlorofluorocarbons (CFCs), contribute to the reduction of the earth’s ozone layer. The ozone layer is a vital part of the earth’s atmosphere and protects life from the harmful effects of excessive ultraviolet (UV) radiation, which come from the sun. 1. UV-B radiation -- On land, ultraviolet radiation endangers all living forms. The dangers of Ultraviolet Radiation are: • Harmful to human health • Causes skin cancer • Causes eye cataracts • Suppresses man’s immune system • Arrest the growth of crops and trees • Practically destroy all life on earth 2. What is Ozone Layer? Ozone layer is a thin, fragile shield of kind oxygen in the stratosphere. It envelops the entire earth and blocks off most of the harmful UV rays from the sun from reaching the earth’s surface. 3. What is “0zone hole?” Ozone hole refers to the loss of the blocking effect of ozone against ultraviolet rays. This is the consequence when the ozone layer is severely depleted, in effect allowing the entry of greater concentrations of UV-B imperiling all living things on earth. a visual representation of ozone hole 4. What is ozone depletion? Ozone depletion is the loss of the blocking effect of the ozone layer against UV rays from the sun. The continuous use of ozone depleting substances (ODS) like CFC and halons destroy the ozone layer. a visual representation of ozone layer depletion 5. What is Greenhouse Effect and Global Warming— Another environmental effect of refrigerants is their possible contribution to global warming. The theory of global warming states that, due to mankind’s activities, the concentration of certain heat-trapping gases is increasing in the atmosphere. This is believed to be causing the mean temperature of earth’s atmosphere to increase slowly. Refrigerants may contribute to global warming by way of a phenomenon called the greenhouse effect. a visual representation of greenhouse effect and global warming Lesson 2 Recovery, Recycling, Reclamation • Recover: to remove refrigerant in any condition from a system and store an external equipment in container • Recycle: to reduce contaminants in used refrigerants by separating oil, removing non- condensable gases, and using devices such as filter- driers to reduce moisture, acidity and particulate matter. • Reclaim: to process used refrigerant to a new product (gas) specifications, and verify by chemical analysis of the refrigerant that new Training Package HCFC Phase‐out RACSS – UNEP 2013 product specifications have been met. Methods of Recovery • Passive (No external recovery machine used) ❖ Charge migration method ❖ Use of system compressor Charge Migration Method – Passive 1. Movement of refrigerant due to natural difference in pressure between system & recovery cylinder. 2. Process can be speeded up by: • Evacuating recovery cylinder • Placing recovery cylinder in ice bath 3. Only a small percentage of charge can be recovered a visual representation of passive method of recovery • Active ❖ With a recovery machine a visual representation of active method of recovery Quiz: MULTIPLE CHOICE: Identify the correct word/s on the following statement. Encircle the letter of the correct answer. 1. is the loss of the blocking effect of the ozone layer against UV rays from the sun. A. Ozone layer B. Ozone hole C. Ozone depletion D. Ozone depleting substances 2. Are used in the wide range of household and industrial uses A. Ozone layer B. Ozone hole C. Ozone depletion D. Ozone depleting substances 3. It is known as the “Clean Air Act of 1999”, it is intended to formulate a holistic national program on air pollution. A. Republic Act No. 8749 B. Republic Act No. 8479 C. Republic Act No. 8947 D. Republic Act No. 8497 4. It is otherwise known as the “Toxic Substances and Hazardous and Nuclear Waste Control Act of 1990”. A. Republic Act No. 6966 B. Republic Act No. 9696 C. Republic Act No. 6969 D. Republic Act No. 8989 5. It is a pact agreed on by governments at the United Nations conference in Kyoto, Japan in 1997 to reduce the amount of greenhouse gases emitted by developed countries by 5.2 percent of 1990 levels during the five-year period 2008-2012. A. Koyo Protocol B. Goto Protocol C. Kyoto Protocol D. Montreal Protocol Job Sheet 1: Recovery of Refrigerant Performance Given a qualification, you should be able to perform Objective: optimum recovery of refrigerant Supplies/Materials: Clean rags, Liquid soap, water, Masking tape, Marker Equipment: DomRAC unit, Recovery machine w/ accessories, Steps/Procedure: Gauge manifold, Vacuum pump, Refrigerant weighing scale, Refrigeration rachet, I. Standard Liquid/Vapor Recovery Method 1. Make sure the unit is in good operating condition. Note: • All connecting port must have cap, if left open perform evacuation procedure. • If a diff. refrigerant will be recovered perform evacuation. 2. Make sure all connections are correct and tight. A. Connect blue hose of gauge manifold to low side access valve. (If there is no access valve installed, a piercing valve must be use.) B. Connect yellow hose of gauge manifold to inlet of filter drier, connect accessory hose (short blue hose) to the outlet of filter drier and the other end to IINPUT port of recovery machine. C. Connect one end of hose to outlet of recovery machine and the other end to recovery tank (Use an extra hose if needed) Note: Recovery tank must be vacuum and weigh before sue. 4. Make sure the Recover/Purge valve is set on Recover. 5. Open the output port of the unit. 6. Open the liquid port on your manifold gauge set; opening the liquid port will remove the liquid from the system first. After the liquid has been removed, open the manifold vapor port to finish evacuating the system. a visual representation of recovery of refrigerant hose connection 7. Connect the unit to a right outlet. (See the nameplate on the unit) Switch the power switch to the ON position and press “Start” to start the compressor. Note: If the unit fails to start, rotate the Input valve and the Recover/Purge valve to Purge position. Then rotate the Recover/Purge valve to Recover position, and open the Input valve. a visual representation of refrigerant recovery machine front panel 8. Slowly open the input port on the unit. 1) If the compressor starts to knock, slowly throttle back the input valve until the knocking stops. 2) If the input valve was throttled back, it should be fully opened once the liquid has been removed from the system (the manifold gauge set vapor port should also be opened at this time). 9. Run until desired vacuum is achieved and the unit shuts down automatically. 1) Close the manifold gauge sets vapor and liquid ports. 2) Close the unit’s input port. 3) Turn off the unit and proceed with the Self-Purge Method on the next page. CAUTION: Always purge the unit after each use. Failure to purge the remaining refrigerant from the unit could result in the acidic degradation of internal components, ultimately causing premature damage. II. Self-Purging Method Procedure for purging remaining refrigerant from this unit 1. Turn INPUT valve to CLOSE; OUTPUT valve to OPEN, and recovery tank valve to OPEN. 2. Turn the Recover/Purge valve to the Purge position. 3. Check the connection hose, and ensure all connections are correct and tight. (Same as recovery mode) 4. Power on, press “Start” and get started. 5. Turn INPUT valve to “PURGE” slowly, and run this unit until desired vacuum level is achieved and / or low-pressure protector shuts off automatically. 6. Close the ports on the recovery tank. 7. Turn the Power-off, disconnect all hoses and dry the filter. 8. Turn Self-purging to “RECOVER” position, and both INPUT and OUTPUT valves to “CLOSE” position. 9. Finally, cover the cap on INPUT and OUTPUT connection adaptor. 10. Leak test recovery tank for leak. Note: Use electronic leak detector if not available, use soap and bubble solution. 11.Weigh recovery tank, put label and record the recovered refrigerant. Performance Criteria Checklist CRITERIA YES NO 1. Does the recovery machine in good condition? 2. Does the hoses connect properly? 3. Does the Recover/Purge valve is set on Recover? 4. Does the output port and liquid port open before switching on the machine? 5. Does the unit plug into right outlet and switch to on position? 6. Does the input port on the unit fully opened? 7. Does vacuum achieve and the unit shuts down automatically? 8. Does the input valve turn to close and put the recovery/purge to purge position? 9. Does the recovery tank close after purging and leak tested? 10. Does the recovered refrigerant weigh and recorded? Trainer’s Signature: Comment/Feedback: TITLE Perform refrigerant recovery/recycling and retrofitting/ conversion on OBJECTIVES domestic refrigeration In this lesson you will be able to understand the importance of INTRODUCTION recovery of refrigerant and perform optimum recovery of refrigerant according to RAC Code of Practice Retrofitting is the process of preparing a refrigeration and air conditioning system for use with a replacement refrigerant and lubricant. The basic idea of retrofit is to replace the refrigerant and refrigerating machine oil. TOPIC 2 DomRAC systems retrofitting overview Lesson 1 Basic consideration for retrofitting Basic Consideration for Retrofitting • Consider the expected energy efficiency, performance and operating costs of the retrofitted system in addition to the direct retrofit costs. • Consider the properties of the alternative refrigerant such as flammability, toxicity and its global warming potential; some of these properties may require additional safety measures. • Consider retrofitting when major damage of the existing system requires expensive repair work. • Consult the system manufacturer for the appropriate alternative refrigerant/lubricant system and the necessary replacement of system components, such as compressor, filters, drier etc., before retrofitting. • Consult the system manufacturer for the appropriate retrofitting procedure, which is, in general, equipment-specific. • Investigate the operating parameters and performance data of the existing system before retrofitting. • Investigate the operating parameters and performance data of the system and control settings after completion of the retrofit. • Re-label the retrofitted system and components to reflect the refrigerant and lubricant change and to indicate future service needs. • Record the retrofitting procedure in the service logbook. Note: Observe local regulations concerning the collection, transport, storage and. destruction of hazardous waste; contact refrigerant suppliers, refrigeration associations or appropriate government institutions I. Assess Unit for Retrofit Retrofitting would appear to be a simple matter since it involves replacing an old refrigerant with a new one in an existing system. However, because many other factors are involved, it is not generally a simple process. Other economic factors must be considered. These factors include: • The estimated equipment life, • Current performance, • Operating requirement, and • The cost of equipment and equipment room modification, maintenance, refrigerant and electrical power. II. Retrofit Factor and Costing 1. The decision to replace or convert existing equipment should be made only after carefully considering the total costs of both scenarios. To minimize the cost, if timing permits, it is best to undertake a retrofit operation around a major maintenance period. Many of the components would normally be replace during a major maintenance overhaul. Note: Retrofits when compressor has failed and will be replaced is much more cost effective 2. Many air-conditioning and refrigeration system running on CFC will be retrofitted to ozone friendly HFCs (i.e. 134a etc.) refrigerants. This will require flushing the mineral oil from the systems and replacing it with synthetic ester lubricants. To be able to perform such a task the service contractor needs to be well aware of the retrofit performance and what to consider. 3. Several factors should be considered when approaching a refrigerant retrofit: • Alternative refrigerant cost. • Availability of alternative refrigerants in the present and the future. • Expected life of existing equipment. • Refrigerant leak history of equipment. . 4. As a service technician, it is your work to advice equipment owner the best way to minimized cost, and at the same time maximizes the efficiency of the equipment. Example on costing is shown below: No. Measure Unit Cost/Unit Hours Cost/Hour Cost 1 Assessment 1 100 100 No Recovery to change oil - 3 Change oil 1 Recovery to change 3x1L 800 3x2 100 3000 refrigerant 2 100 200 1 New refrigerant 1 New filter 3 kg 300 1 100 1000 1 pc. 500 500 1 Commissioning 1 100 100 Total cost of retrofit 4900 III. Alternative Refrigerants and Lubrication 1. In selecting ozone-compatiblealternatives for CFCs, two molecular concepts are to be used: • Eliminate (or at least minimize) C- Cl bonds, and • Include C-H bonds This is in addition to maintaining the desirable physical and physiological properties already ascribed to the CFCs. 2. With these criteria set forth, the major CFCs producers, such as DuPont, Solvay, and ICI, searched the tables of known fluorocarbons in an attempt to match these properties. From these tables, which are extensive only a few compounds approximate the physical properties of the existing CFCs. The following table identifies these compounds: