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Refrigeration Oils*
With the changes that have taken place in our industry due to the CFC issue, we have reevaluated our lubricants to ensure compatibility with the new HFC refrigerants and HCFC interim blends offered by several chemical producers. As a secondary criteria, it is also desirable that any new lubricant be compatible with the traditional refrigerants such as CFC-12, HCFC-22 or
R502. This “backward compatibility” has been achieved with the introduction of the Polyol ester lubricants.
Table 3 below summarizes which oils/lubricants are approved for use in Copeland compressors:
Polyol Ester Lubricants
Color
As received, the POE lubricant will be clear or straw colored.
After use, it may acquire a darker color. This does not indicate a problem as the darker color merely reflects the activity of the lubricantʼ s protective additive.
Oil Level
During Copelandʼ s testing of Polyol ester oil, it was found that this lubricant exhibits a greater tendency to introduce oil into the cylinder during flooded start conditions. If allowed to continue, this condition will cause mechanical failure of the compressor.
Hygroscopicity
Ester lubricants (POE) have the characteristic of quickly absorbing moisture from the ambient surroundings. This is shown graphically in Figure 3 where it can be seen that such lubricants absorb moisture faster and in greater quantity than conventional mineral oils. Since moisture levels greater than
100 ppm will results in system corrosion and ultimate failure, it is imperative that compressors, components, containers and the entire system be kept sealed as much as possible. Lubricants will be packaged in specially designed, sealed containers.
After opening, all the lubricant in a container should be used at once since it will readily absorb moisture if left exposed to the ambient. Any unused lubricant should be properly disposed of.
Similarly, work on systems and compressors must be carried out with the open time as short as possible. Leaving the system or compressor open during breaks or overnight MUST BE
AVOIDED!
A crankcase heater is required with condensing units and it must be turned on several hours before start-up.
Oil level must not exceed 1/4 sight glass.
Figure 3.
Mineral Oil
Table 3. Refrigeration Oils
POEʼs
Mineral
Oils
A/B
Refrigeration Oils
Mobil EAL ARCTIC 22 CC
ICI (Virginia KMP) EMKARATE RL 32CF
Suniso 3GS
Texaco WF32
Calumet RO15 (Witco)
Sontex 200-LT (White Oil)
Witco LP-200 P
HCFC-22
A
A
P
P
P
(BR & Scroll Only)
Interims
Traditional Refrigerants R401A, R401B, R402A
(MP-39, MP-66, HP-80) R404A, R507
A
A
PM
PM
PM
HFCʼs
HFC-134a,
P
P
NOT
ACCEPTABLE
Zerol 200TD
Soltex Type AB-200
AM PM
PM
NOT
ACCEPTABLE
P = Preferred Lubricant Choice A = Acceptable Alternative M = Mixture of Mineral Oil and Alkyl Benzene (AB) with minimum 50% AB.
* (Reprinted with permission from Copeland)
Mineral Oils
The BR and Scroll compressors use Sontex 200, a “white oil”.
This oil is not suitable for low temperature applications nor is it available through the normal refrigeration wholesalers. For field “top-off” the use of 3GS or equivalent, or Zerol 200TD is permissible, as long as at least 50% of the total oil charge remains Sontex 200.
Suniso 3GS, Texaco WF32 and Calumet R015 (yellow oils) are available through normal refrigeration wholesalers. These oils are compatible if mixed and can be used on both high and low temperature systems.
Polyol Ester Lubricants
The Mobil EAL ARCTIC 22 CC is the preferred Polyol ester due to unique additives included in this lubricant. ICI Emkarate RL 32S is an acceptable Polyol ester lubricant approved for use when Mobil is not available. These POEʼs must be used if HFC refrigerants are used in the system. They are also acceptable for use with any
6
of the traditional refrigerants or interim blends and are compatible with mineral oils. They can therefore be mixed with mineral oils when used in systems with CFC or HCFC refrigerants. These lubricants are compatible with one another and can be mixed.
Alkyl Benzenes
Zerol 200TD is an alkyl benzene (AB) lubricant. Copeland recommends this lubricant for use as a mixture with mineral oil
(MO) when using the interim blends such as R-401A, R-401B and R-402A (MP39, MP66 and HP80). A minimum of 50% AB is required in these mixtures to assure proper oil return.
Shell MS 2212 is a 70/30 mixture of AB/MO. If this lubricant is used in a retrofit situation virtually all of the existing MO must be drained prior to refilling with the MS 2212 to assure a minimum
50% AB content.
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