Emerson Copeland 4MF-13X - Maintenance and Refrigerant Handling

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Maintenance
Exchanging the Refrigerant
Qualied refrigerants and oils are given in Application Range (Qualied Refrigerants and Oils).
It is not necessary to replace the refrigerant with a new one, unless contamination due to an error such as topping up the system with
an incorrect refrigerant is suspected. To verify correct refrigerant composition, a sample can be taken for chemical analysis. A check can
be made during shut down by comparing the refrigerant temperature and pressure using precision measurements at a location in the
system where liquid and vapour phases are present and when the temperatures have stabilised.
In the event that the refrigerant needs replacing, the charge should be recovered using a suitable recovery unit.
In the event that R22 in a system with mineral oil is to be replaced with R407C or R404A, the oil must also be changed.
NOTE: Please refer to Technical Information C7.26.1 “Refrigerant Changeover from HCFC to HFC Refrigerants”.
Replacing a Compressor
In the case of a motor burnout, the majority of contaminated oil will be removed with the compressor. The rest of the oil is cleaned
through the use of suction and liquid line lter driers. A 100% activated alumna suction line lter drier is recommended but must be
removed after 72 hours. It is highly recommended that the suction accumulator be replaced if the system contains one. This is
because the accumulator oil-return orice or screen may be plugged with debris or may become plugged shortly after a compressor
failure. This will result in starvation of oil to the replacement compressor and a second failure. When a single compressor or tandem is
exchanged in the eld, it is possible that a major portion of the oil may still be in the system. While this may not affect the reliability of the
replacement compressor, the extra oil will add to rotor drag and increase power usage.
Lubrication and Oil Removal
The compressor is supplied with an initial oil charge. The standard oil charge for use with refrigerants R404A / R407A / R407C / R407F /
R134a is a polyolester (POE) lubricant Emkarate RL 32 3MAF. In the eld the oil level could be topped up with Mobil EAL Arctic 22 CC if
3MAF is not available. The standard mineral oil for R22 is Suniso 3GS.
One disadvantage of POE is that it is far more hygroscopic than mineral oil (see Figure 14). Only brief exposure to ambient air is needed
for POE to absorb sufcient moisture to make it unacceptable for use in a refrigeration system. Since POE holds moisture more readily
than mineral oil it is more difcult to remove it through the use of vacuum. Compressors supplied by Emerson Climate Technologies
contain oil with low moisture content, and it may rise during the system assembling process. Therefore, it is recommended that a
properly sized lter-drier is installed in all POE systems. This will maintain the moisture level in the oil to less than 50 ppm. If oil is charged
into a system, it is recommended to use POE with a moisture content no higher than 50 ppm.
CAUTION
Inadequate lubrication! Bearing destruction! Exchange the accumulator after replacing a compressor with a burned out motor.
The accumulator oil return orice or screen may be plugged with debris or may become plugged. This will result in starvation of oil
to the new compressor and a second failure.
CAUTION
Chemical reaction! Compressor destruction! Do not mix up ester oils with mineral oil and/or alkyl benzene when used with
chlorine-free (HFC) refrigerants.