R-410a Refrigerant Cycle Diagnostics

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R-410a Refrigerant Cycle Diagnostics
Mark StokesTechnical Training Manager
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R410a Training

• R410 Refrigerant Why and When?
• Basic Refrigeration Cycle
• Importance of Airflow
• Installation
• Troubleshooting

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Amana Brand R-410A Training
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R410a Refrigerant

• What is it?
• Why and when will it be coming?

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• 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.

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CFC, HCFC,HFC CFCs (chlorofluorocarbons) These
have a high ozone-depleting potential (ODP)
contributing to the breakdown of the ozone layer,
are banned by the 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 the Montreal
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.
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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

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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
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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

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R-410A

• Its 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.

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The Future Refrigerant R-410A

• Azeotrope/Near Azeotrope
• Temperature Glide
• Fractionation

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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

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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.

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Components that needed Redesigned for R-410A

• Compressor
• Condenser Coil
• Filter Drier
• Expansion Device
• Evaporator
• Pressure Switches

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Compressors

• Copeland ZRS and ZPS Compressors
• We will get further into these later in the
  program.

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Pressure Switches

• Pressure Switches have to be at higher settings
• Low Pressure R-410A 50psi
• High Pressure R-410A 610psi

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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.

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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.

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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.

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Manifold Gauge Set
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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.

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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.

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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.

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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.

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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.
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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.

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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.

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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.

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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.

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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.

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Evacuation
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Evacuation
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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.

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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.

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A small leak in an R-410A system can cause

1. All of the systems oil to vaporize.
2. All of the systems oil to be contaminated.
3. Little difference in refrigerant composition
4. Major changes in refrigerant composition.

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The high pressure gauge on an R-410A manifold
gauge set typically has a pressure range of

1. 30 to 250 psig.
2. 0 to 500 psig.
3. 0 to 800 psig.
4. 0 to 1200 psig.

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The cylinder color for a disposable container of
R-410A is

1. Maroon
2. Green
3. Blue
4. Rose

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Which of the following is a characteristic of POE
oil

1. POE has higher wax content than mineral oil.
2. POE oil will not mix with mineral oil.
3. POE oil is available in only one grade.
4. POE oil is hygroscopic.

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To remove moisture from POE oil requires the use
of a(n)

1. High capacity vacuum pump.
2. Low volume vacuum pump.
3. Liquid line filter drier.
4. Oil separator.

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The preferred method of charging anR-410A system
is

1. Liquid charging through the low pressure valve.
2. Liquid charging through the high pressure valve.
3. Vapor charging through the low pressure valve.
4. Vapor charging through the high pressure valve.

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Which of the following recovery machine features
will help prevent cross contamination between
different types of refrigerants and oils?

1. An oil-less compressor and pump down
   capabilities.
2. A scroll compressor and an internal drier.
3. A piston style compressor and internal oil
   separator.
4. A built in sight glass and moisture indicator.

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Under which of the following circumstances may an
R-22 expansion valve be used with R-410A?

1. The R-22 expansion valve has an adjustable
   superheat control.
2. The system capacity is less than 48,000 btus.
3. The evaporator coil is rated for R-410A.
4. Under no circumstances.

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R-410A is combustible if it is mixed with

1. Oil under a vacuum.
2. Oil under pressure.
3. Pressurized air.
4. Pressurized nitrogen.

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QUESTIONS?
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thank you!
any questions?