General Properties Of Refrigeration Compressor Oils; Oils For Hfc And Hfo Refrigerants - Bitzer BSE32 Manuel

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General properties of refrigeration compressor oils

Refrigeration compressor oils not only have to lubricate the moving compressor parts, but (according to individual
design and circuit) also seal the compression chamber and valves as well as dissipate heat. In order to ensure oil
circulation and return from the system as well as to avoid lack of oil, the oil must be sufficiently soluble in the refri-
gerant (exception: R717 - ammonia, see Technical Information AT-640 ): Phase separation can lead to malfunctions
e.g. in the evaporator, receiver and heat exchanger. Another important parameter is the viscosity over the whole
temperature range: In the compressor, the oil must be adequately viscous, while still flowing sufficiently in the cold
part of the system. In addition, the oil should be age-resistant, thermally and chemically stable.
NOTICE
!
!
Oil with high water content may damage compressor and refrigeration system!
Avoid air intake into the system and oil containers.
Use only originally sealed oil containers. Opened oil containers should be closed tightly and their content be
used up as quickly as possible.
For used oils: Observe the warning values on water content.
Water in the refrigerating circuit can lead to corrosion and to freezing of the expansion valve. It adversely affects
lubricity and stability of the oils. With some refrigerants (e.g. CO
ing acids – the acid in turn corrodes metal surfaces, and the water cannot be removed anymore by evacuation.
Special care is necessary with polyalkylene glycol oils (PAG), polyvinyl ether oils (PVE) and polyolester oils (POE):
They are strongly hygroscopic, i.e. they withdraw water from ambient air. This dissolves in the oil and can therefore
not be recognised visually.
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Oils for HFC and HFO refrigerants

BITZER compressors which are intended for use with chlorine-free HFC and HFO refrigerants (R134a, R404A,
R407A/C/F, R507A, R1234yf, R513A, R450A etc.) are charged with a high-quality polyolester oil. In these cases, a
"Y" is added to the type designation of the compressor. BITZER polyolester oils significantly exceed the require-
ments of DIN 51503, Part 1, for refrigeration compressor oils with respect to water content and total acid number
(TAN). They mix well with HFC and HFO refrigerants and are therefore especially suitable for operation with these
substances.
Characterising the oils
Oil Oil type
BSE32 polyolester oil (POE) standard oil charge
BSE55 polyolester oil (POE) alternative oil charge for condensing tem-
BSE85K polyolester oil (POE) oil charge for special applications
Tab. 1: BITZER oils for HFC and HFO refrigerants in reciprocating compressors
Initial charge only with original oils
NOTICE
!
!
Risk of compressor damage!
BITZER polyolester oils are mandatory for the running-in period of the compressor. Use only these oils for
the initial charge!
BITZER polyolester oils are characterised by specific tribological characteristics and have special wear protection
additives which increase the service life of the compressor. The use of alternative oils whose characteristics corres-
pond largely to the original charge is only possible at the system owner's own responsibility. It is possible to mix
them with the original oil, within the respective viscosity group, as long as appropriate own or comparable experi-
ence is available for the application concerned. Generally, mixing different oil types may have a negative effect on
KT-500-9 // PDF Download
Applications
perature t > 70°C (available for many com-
c
pressors)
) or oils (e.g. ester oils), water also reacts by form-
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Designation on compressor
"Y" (e.g. 2CES‑4Y)
"Y" (e.g. 2CES‑4Y)
"Y" (e.g. 2CES‑4Y)
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