The document discusses the importance and functions of lubricants in refrigeration systems, emphasizing the need for chemical stability and resistance to contamination. It examines various types of refrigerant contamination and the effects on system efficiency, as well as safety and recovery procedures for refrigerants. Additionally, it covers oil contamination, its impact on performance, and key safety calculations for refrigerant storage tanks.

1. LUBRICANTS

2. LUBRICATION (OIL)

Lubrication is the process by which the moving parts
such as bearings in the compressor are kept separate
by a film of oil to maximize performance and reduce
wear and tear.

Create a Fluid seal

Acts a coolant in compressor

Dampens noise in compressor crankcase

3. IMPORTANT OIL FUNCTIONS
Refrigerant oil must adequately perform
four basic functions
 Lubricate
 Scaling
off the high side from the low side
 Transferring heat

4. IMPORTANT OIL FUNCTIONS

Damper compressor noise


Oils should be chemically stable
It should not react chemically with its




Refrigerants contained in the system
Metals
Motor insulation
Also it should not react readily to the presence of
normal contaminants



Non condensable
Moisture
Flux/ wax

5. REFRIGERATION SYSTEM
LUBRICATION

As the name suggests, refrigeration system
lubrication lubricates the system using Mineral
Oil, Polyalkylene Glycol, Alkyl benzene and
Polyol Ester depending on the type of
refrigerant being used. It also has the following
functions:

6. LUBRICATION (OIL)
Viscosity…how thick or thin the oil is
 Floc point…the point at which the wax will separate
from the oil
 Pour point…the temperature at which it ceases to
flow
 Dielectric strength…a measure of a oils resistance to
electrical current
 Colour… refining to a lighter coloured oil
 Specific gravity…weight
 Neutralization number…organic acid content


7. LUBRICATION (OIL)
Oxidation resistance… resist water and O2
 Moisture content…dryness of oil
 Chemical stability… in presence or metal or
refrigerants will chemicals
in the oils attack the metal and ref.
 Flash point… the temperature at which the oil
vapour flash burns
 Fire point…the temperature at which the oil
maintains combustion


8. OIL DEFINITIONS

Hygroscopic
A Hygroscopic oil is one that easily absorbs &
releases moisture (has a high affinity for water).
 Most refrigerant oils are hygroscopic
 An oil sample should be taken and analyzed if a
system has had a major component failure.


9. OIL DEFINITIONS

Viscosity

The resistance that the oil offers to flow. High
viscosity means a thick oil, low viscosity means a
thin oil. The body of the oil or its ability to perform
a lubricating function. Sometimes referred to as the
thickness of the oil.

10. OIL DEFINITIONS

Material Compatibility

The oil or refrigerant must not react, swell, shrink,
deteriorate, weaken, pit, or extrude any materials
used in refrigeration equipment.

11. OIL DEFINITIONS

Chemical Stability

An oil’s ability to perform for an extended life
without breaking down or chemically reacting with
other materials.

12. OIL DEFINITIONS

Dielectric strength

An oil’s relative electrical resistance to electrical
current.

13. CONCLUSION

In general, there is no “best” oil. Follow
manufacturers’ recommendations for best
performance.

14. CONTAMINANTS

15. Refrigerant Contamination

There are four types of contamination that can
occur in any refrigeration equipment which will
hinder performance, efficiency and in extreme
cases, system failure and damage of components
which will be costly to repair and replace:

16. Refrigerant Contamination




Air Contamination
Oil Contamination
Water/Acid Contamination
Cross Contamination with other Refrigerants.
(mixture of incompatible refrigerant)

17. Air / Non Condensable
Contamination

Air or Non-Condensable gas is one of the most
difficult contaminants to remove from an
operating system.

Air in a system can cause excessive head pressure
and higher operating temperatures. It also causes
loss of heat transfer efficiencies by acting as an
insulator around heat exchanger tubes.

18. Air / Non Condensable
Contamination

This translates into higher utility costs, degradation
of lubricant effectiveness, and premature
compressor problems like increased compressor
temperatures and pressures, reduced cooling
capacity, increased compressor pressure ratios,
potential compressor overheating, and finally,
compressor motor burn-out.

19. Air / Non Condensable
Contamination

Typically, a pressure more than 20 PSI above the
saturation pressure indicates that a noncondensable gas problem may exist. If noncondensable gases are trapped in the
system, recovering vapour from the condenser
should remove these non-condensable gasses and
reduce the pressure discrepancy.

20. Air / Non Condensable
Contamination

Purging the system with nitrogen gas after
removing the refrigerant using a recovery
machine is also another service option. In
addition, purging is best used with high efficiency
purge unit or to reclaim the refrigerant after
recovery.

21. Moisture/ Acid Contamination

The moisture and refrigerant combine to form acids
that can destroy motor windings and result in motor
burnout.

Oil sludge and particulates can clog coalescing oil filters
and metering devices. Any water in the system will
most likely freeze in the expansion valve because this is
the point where refrigerant is cooled by the evaporation
occurring as a result of the sudden pressure drop, and
the expansion device also represents the smallest
passageway in the overall system. This is the reason
why liquid line filter-driers are typically located just
upstream of the expansion device.

22. Moisture/ Acid Contamination

When this situation occurs, it is necessary to not only
clean the refrigerant, but it is also imperative that the
refrigeration system be totally dehydrated to remove all
traces of water. It is usually desirable to also flush the
system to remove rust and other particulates that may
have developed while the refrigeration system was
being repaired.

23. Oil Contamination

Over time it is very common for oil to migrate from the
compressor. Oil accumulates in the evaporator and
insulates the tubes. This inhibits maximum heat transfer
and reduces system efficiency. Studies indicate that for
every 1% of oil in the evaporator, a system loses 2%
efficiency.

24. Oil Contamination

This translates into reduced comfort, higher utility
costs, or both. The typical way of dealing with oil
contamination is decontaminate the refrigerant with an
oil purge unit or charge with new refrigerant after
removal of the existing charge with a recovery machine.

For large systems like chillers, an oil purging unit is
sometimes installed as a continuous prevention of oil
contamination.

25. Cross Contamination

This type of contamination may result if the system is
mistakenly charged with:




An incompatible refrigerant for the system.
Improper charging of blends resulting in incorrect
proportional mixture.
An already contaminated refrigerant
In such cases, the refrigerant is recovered using
recovery machine, purged of oil and contaminants and
dehydrated prior to charging with clean refrigerant after
checking the system for leaks and doing the necessary
repair job.

26. SAFETY
PROCEDURES

40. RECOVERY
RECYCLE
RECLAIM

41. RECOVERY
Refrigerant recovery means to remove
refrigerant in any condition from an appliance
and store it in an EXTERNAL CONTAINER.
Refrigerant recovery takes place mainly at three
major stages of equipment lifetime.

42. When To Perform Recovery



during servicing when part or complete
refrigerant charge shall be removed of
the system,
when the system is converted to be run
with a new refrigerant,
At equipment disposal

43. RECYCLE
To clean refrigerant for reuse by separating
the oil from the refrigerant and removing
moisture by passing it through one or more
filter driers
Current recovery machines have filters that
remove contaminants from the refrigerants
including acids that will enable the refrigerant to
be reused.

46. RECLAIM
To process refrigerant to a level
equal to new product standards as
determined by chemical analysis.
Reclaimed refrigerant must meet
standards set forth in ARI 700 before
it can be resold.

65. BASIC TOOLS






MANIFOLD GAUGE
REFRIGERANT LEAK DETECTOR
VACUUM PUMP & MICRON GAUGE
CHARGING SCALE
RECOVERY TANK
RECOVERY MACHINE

66. 
Insert topic Good Service practices

77. NEW SYSTEM
REQUIREMENTS

78. 
INSERT THE VARIOUS MANIFOLD
GRAPHICS

79. 

Talk about new refrigerants replacing CFC and
HCFC like 134a and 400 series which operates
at higher pressure.
Gauge manifold to cater for these new
refrigerants should be used.

87. RECOMMENDED
TOOLS

96. 
Insert more detailed gauge reading

106. RECOVERY CYLINDERS
Approved refrigerant recovery cylinders can easily be
identified by their colors, YELLOW TOPS and GRAY
BODIES. All refrigerant recovery cylinders should be
inspected for RUST. If they show signs of rust or appear
to not be secure they should be reduced to 0 psig and
discarded.

108. 
Tunjuk tank besar

113. O

115. E

119. TANK SAFETY CALCULATION

WE HAVE A RECOVERY TANK WITH A
SPECIFICATION OF BA300
Q1: WHAT IS THE TEST PRESSURE?
 Q2: WHAT IS THE RELIEF PRESSURE?


120. TANK SAFETY CALCULATION

TEST PRESSURE
= SERVICE PRESSURE X 2
 = 300 X 2 = 600 PSI


RELIEF PRESSURE
= 75% X TEST PRESSURE
 = 75% X 600 PSI = 450 PSI


121. TANK SAFETY CALCULATION


Q3: CAN R22 GAS BE KEPT IN A BA300
TANK?
ANSWER:
TAKE THE PRESSURE OF R22 AT 130F
TEMPERATURE FROM THE PT CHART
 R22 PRESSURE AT 130F IS 297 PSI
 THIS PRESSURE MUST BE LESS THAN 5/4 X
SERVICE PRESSURE OF BA300 TANK


122. TANK SAFETY CALCULATION




THEREFORE:
5/4 X 300 (SERVICE PRESSURE OF BA300
TANK) => (5 X 300)/4 = 375 PSI
375 PSI IS MORE THAN THE PRESSURE
OF R22 AT 130F THAT IS 297 PSI
SO, R22 CAN BE SAFELY KEPT INSIDE A
BA300 TANK

123. TANK SAFETY CALCULATION



ADDITIONAL QUESTION
CAN R507 GAS BE KEPT IN BA300 TANK?
ANSWER




PRESSURE OF R507 AT 130F IS 368 PSI
5/4 X 300 (SERVICE PRESSURE OF BA300 TANK) =>
(5 X 300)/4 = 375 PSI
375 PSI IS MORE THAN THE PRESSURE OF R507 AT
130F THAT IS 368 PSI
SO, R507 CAN BE SAFELY KEPT INSIDE A BA300
TANK

124. TANK SAFETY CALCULATION



ADDITIONAL QUESTION
CAN R507 GAS BE KEPT IN BA300 TANK?
ANSWER




PRESSURE OF R410A AT 130F IS 475 PSI
5/4 X 300 (SERVICE PRESSURE OF BA300 TANK) =>
(5 X 300)/4 = 375 PSI
375 PSI IS LESS THAN THE PRESSURE OF R410A AT
130F THAT IS 475 PSI
SO, R410A CANNOT BE KEPT IN A BA300 TANK
SAFELY

155. THANK YOU