R-410a Refrigerant Cycle Diagnostics. Mark Stokes Technical Training Manager. R410a Training . R410 Refrigerant… Why and When? Basic Refrigeration Cycle Importance of Airflow Installation Troubleshooting. Amana ® Brand R-410A Training. R410a Refrigerant. What is it?
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R-410a Refrigerant Cycle Diagnostics Mark StokesTechnical Training Manager
R410a Training • R410 Refrigerant… Why and When? • Basic Refrigeration Cycle • Importance of Airflow • Installation • Troubleshooting
R410a Refrigerant What is it? Why and when will it be coming?
Definitions of Refrigerants • A refrigerant is a fluid used for heat transfer in a refrigeration system. • Most refrigerants absorb heat during evaporation at low temperature and low pressure and reject heat during condensation at a higher temperature and higher pressure.
CFC, HCFC,HFC CFCs (chlorofluorocarbons) These have a high ozone‑depleting potential (ODP) contributing to the breakdown of the ozone layer, are banned bythe Montreal Pro (an international agreement to protect the earth's ozone layer) and has been ceased to be manufactured in the European Community (e.g.R11, R12 and R114.) HCFCs (hydrochlorofluorocarbons) These have limited ODP are classified under theMontreal Protocol as transitional substances and are due to be phased out early this century. Examples are R22, R123 and R124. HFCs (hydrofluorocarbons) These contain no chlorine and therefore have zero ODP ` and in consequence are not controlled by the Montreal Protocol. Examples are R410a, R134a and R152a. R134a can be substituted directly, requiring replacement of some serviceable' components only for R12.
% $20/lb 100 R-22 Cost Montreal Protocol/US Phase-Out 65% % 1996 CAP $10/lb 50 35% EU Phase-Out 10% $2/lb 0 1999 2004 2010 2015 2020 No New Equip. US No New Equip. EU R-22 Phase-Out Timeline • New installations banned 2004 in Europe and 2010 in US • Service end 2010 in Europe and 2020 in US • Europe driving accelerated phase-out dates • All dates could be accelerated
US New Refrigerant Transitions R-134A Screw Chillers60- 500 Ton R-22 R-410A R-407C Commercial5 to 100 Ton R-22 R-410A R-410A Residential1.5 to 5 Ton R-22 1990 1995 2000 2005 2010
R-410A Facts • Ozone friendly- No Chlorine • Replacement for R-22, NOT a drop in! • Higher Pressure Range-50 to 75% higher than R-22 • Requires Special Lubricants
R-410A • It’s a Blended Refrigerant. • 50% R-32 and 50% R-125. • This blend is a near-azeotrope, not a true azeotrope like R-502. • A true azeotrope is a mixture that maintains its composition through both the liquid and vapor phase.
The Future Refrigerant R-410A • Azeotrope/Near Azeotrope • Temperature Glide • Fractionation
R-410A • For a near-azeotrope, the individual refrigerants evaporate or condense at different temperatures. • The differences between these boiling points with mixed refrigerants is called: “ TEMPERATURE GLIDE” • When temperature glide is high the refrigerants can separate during evaporation or condensation. • This changes the composition of the resulting vapor and liquid. • This separation is called: “FRACTIONATION”
R-410A • Another significant difference between R-410A and R-22 is its saturation pressure range. • R-410A has a higher pressure range curve than R-22. • Remember, R-410A is a near azeotrope that is subject to some fractionation. At any specific temperature it has a higher vapor pressure when saturated.
Components that needed Redesigned for R-410A • Compressor • Condenser Coil • Filter Drier • Expansion Device • Evaporator • Pressure Switches
Compressors • Copeland ZRS and ZPS Compressors • We will get further into these later in the program.
Pressure Switches • Pressure Switches have to be at higher settings • Low Pressure R-410A = 50psi • High Pressure R-410A = 610psi
Line Sets • New Line Sets are always recommended, but required if: • The previous system had a compressor burn out. • The existing line set has oil return traps. • The existing line set has been open to the atmosphere for an extended time. • The existing line set is larger than or smaller than the recommended line size for the Amana® R-410A system. • The existing line set is damaged, corroded, or shows signs of abrasion/fatigue.
Special Tools Required • Differences in Saturation Pressures between R-22 and R-410A affects many of the tools the Technician must use when Charging and Servicing an R410A system. • Some of the tools used on R-22 systems may be unacceptable for use on R410a systems.
Manifold Gauge Set • Standard Gauges and hoses cannot be used safely with R410A. • The High Side gauge should have a range of zero to 800psi. • The Low Side gauge should have a range from 30 inches vacuum to 250psi. • The Low Side gauge should also have a 500psi retardation feature. This slows the movement of the gauge needle at higher pressures.
Refrigerant Hoses • The 600psi rating of standard hoses is NOT adequate for R410A. • Hoses need to be rated for a 800psi working pressure, with a 4000psi bursting rating. • 5 to 1 safety margin is necessary to prevent dangerous hose ruptures.
Vacuum Pumps • Pumps used with CFC and HCFC charged systems may also be used on R410A systems as long as the pump is capable of attaining a vacuum of level of at least 250 Microns.
Leak Detectors • Leak detectors should be checked to see that they are designed to properly detect R410A. • The detector should have adjustable sensitivity to allow leaks to be pinpointed in areas where background vapor might cause false readings.
R-410A • The temperature glide of R-410A is very low, thus it acts very much like a single refrigerant. • Fractionation is very low. • R-410A does not significantly separate in the system and the composition of the refrigerant has very minor changes if a leak occurs. • But the fact that some fractionation occurs, means that charging techniques must be adjusted.
Cylinders • Most R-410A cylinders have an internal dip tube which allows the feeding of liquid when the cylinder is in an upright position. They must be inverted for for vapor flow. • Color is rose (pink). • The cylinder has to have minimum cylinder pressure requirement of 400 psig rating (DOT 4B400 or DOT 4BW400) NOTE: Avoid storing R-410A where temperatures will exceed 120° F.
Lubrication • The chemistry of R-410A makes it incompatible with mineral based lubricants. • Mineral oils typically used with R-22 has relativity low Miscibility with R-410A. • Miscibility is the ability of an oil to dissolve uniformly in refrigerant in either the liquid or vapor state.
Lubrication • The preferred lubricants are the Polyolester or ester based oils. • Commonly known as POE oils. • POE oils are miscible with any mineral oil traces that might be in the system. • While miscible, it is very important to remove as much mineral oil, particulates, and moisture from existing line sets as possible.
Lubrication • The POE oils are more Hygroscopic than mineral oils. • This means that they absorb moisture very rapidly. • Exposure to the atmosphere must be limited. • The oil will break down into acid and alcohol. • Keep the system closed.
Lubrication • Any moisture absorbed by into POE oils cannot be removed with a vacuum pump-Only a new drier will work! • Break a recovery vacuum with Nitrogen! • Keep all systems closed until any component replacements are ready for installation.
Brazing • Should be using at least 2% silver alloy. • Always wear glasses and gloves. • Always purge with nitrogen when brazing. • Protect the service valves with wet rags or heat sink material. • Scale will get you with POE oils.
Recovery • Yes, you still have to recover the refrigerant. • R-410A does not readily biodegrade, care should be taken to avoid any releases to the environment. • The recovery machines used for R-410A must be designed to prevent cross contamination between oils and refrigerants.. • Use machines certified for use with R-410A.
Recovery • Preferred type is an oil-less compressor model with a pump down feature for removal of all refrigerant from the machine after each use. • If an oil bearing compressor is used, the machine should be restricted to R-410A refrigerant. The machine must use ester based oil.
A small leak in an R-410A system can cause: • All of the system’s oil to vaporize. • All of the system’s oil to be contaminated. • Little difference in refrigerant composition • Major changes in refrigerant composition.
The high pressure gauge on an R-410A manifold gauge set typically has a pressure range of: • 30 to 250 psig. • 0 to 500 psig. • 0 to 800 psig. • 0 to 1200 psig.
The cylinder color for a disposable container of R-410A is: • Maroon • Green • Blue • Rose
Which of the following is a characteristic of POE oil: • POE has higher wax content than mineral oil. • POE oil will not mix with mineral oil. • POE oil is available in only one grade. • POE oil is hygroscopic.
To remove moisture from POE oil requires the use of a(n): • High capacity vacuum pump. • Low volume vacuum pump. • Liquid line filter drier. • Oil separator.
The preferred method of charging anR-410A system is: • Liquid charging through the low pressure valve. • Liquid charging through the high pressure valve. • Vapor charging through the low pressure valve. • Vapor charging through the high pressure valve.
Which of the following recovery machine features will help prevent cross contamination between different types of refrigerants and oils? • An oil-less compressor and pump down capabilities. • A scroll compressor and an internal drier. • A piston style compressor and internal oil separator. • A built in sight glass and moisture indicator.
Under which of the following circumstances may an R-22 expansion valve be used with R-410A? • The R-22 expansion valve has an adjustable superheat control. • The system capacity is less than 48,000 btu’s. • The evaporator coil is rated for R-410A. • Under no circumstances.
R-410A is combustible if it is mixed with: • Oil under a vacuum. • Oil under pressure. • Pressurized air. • Pressurized nitrogen.
any questions? thank you!