22
FRCC.PC.015.A5.02
Application Guidelines
Operating conditions
The scroll compressor application range is
influenced by several parameters which need to
be monitored for a safe and reliable operation.
These parameters and the main
recommendations for good practice and safety
devices are explained hereunder.
• Refrigerant and lubricants
• Motor supply
• Compressor ambient temperature
• Application envelope
(evaporating
temperature, condensing temperature, return
gas temperature)
General information
Refrigerant and
lubricants
When choosing a refrigerant, different aspects
must be taken into consideration:
• Legislation (now and in the future)
• Safety
• Application envelope in relation to expected
running conditions
• Compressor capacity and efficiency
• Compressor manufacturer recommendations &
guidelines
Additional points could influence the final choice:
• Environmental considerations
• Standardisation of refrigerants and lubricants
• Refrigerant cost
• Refrigerant availability
R22
R22 is an HCFC refrigerant and is still a wide
use today. It has a low ODP (Ozone Depletion
Potential) and therefore it will be phased out in
the future. Check local legislation.
When R22 is applied in refrigeration applications
it can lead to high discharge temperature.
Carefully check all other parameters that can
influence the discharge temperature.
R404A
R507
Alkylbenzene oil
PVE
R404A is an HFC refrigerant. R404A has zero
ozone depletion potential (ODP = 0). R404A
is especially suitable for low evaporating
temperature applications but it can also be
applied to medium evaporating temperature
applications. R404A is a mixture and has a very
small temperature glide, and therefore must
be charged in its liquid phase, but for most
other aspects this small glide can be neglected.
Because of the small glide, R404A is often called a
near-azeotropic mixture.
R507 is an HFC refrigerant with properties
comparable to R404A. R507 has no ozone
depletion potential (ODP = 0). As with R404A,
R507 is particularly suitable for low evaporating
temperature applications but it can also be
used for medium evaporating temperature
applications. R507 is an azeotropic mixture with
no temperature glide.
Polyvinyl ether (PVE) is an innovative refrigeration
lubricant for HFC refrigerant systems. PVE is as
hygroscopic as existing polyolester lubricants
(POE), but PVE doesn’t chemically react with
water; no acids are formed and compressor
evacuation is easier.
As PVE can be mixed with POE, oil top up can be
done with up to 25% POE.
The compressor technology applied in MLZ
compressors in combination with PVE lubricant
provides the best possible result in terms of
reliability and compressor lifetime.
The PVE lubricant is compatible with R22 which
makes the MLZ compressors a very versatile
multi- refrigerant solution. Very high care has
to be taken for vacuum as PVE is much more
hygroscopic than alkylbenzene or mineral oil.
Alkylbenzene oil can be applied in systems
using HCFC refrigerants (R22). Compared to
a mineral oil it provides distinct advantages:
excellent miscibility, excellent thermal stability,
compatibility with mineral oils and constant
quality.
MLM series compressors are charged with
Alkylbenzene oil and herewith offer an
economically interesting alternative to the
MLZ series in regions where R22 is still the
predominant refrigerant. Note however that
MLM compressors can not be used with HFC
refrigerants.
Refrigerant R134a is an HFC refrigerant. R134a
has zero ozone depletion potential (ODP = 0)
and is commonly accepted as the best R12
alternative. R134a is a pure refrigerant and
has zero temperature glide. For applications
with high evaporating and high condensing
temperatures, R134a is the ideal choice.
R134a