2202MYJE-MY-C8-N_2018.02.
Chapter 4 Operation of Compressor and Unit
Compound 2-stage Screw Compressor 3225**C 4.1 Lubricating Oil (Refrigerant Oil)
4-5
4.1.5 Lubricating Oil Management Criteria
Lubricating oils that are managed by the criteria are classified into the following categories:
(1) Synthetic oils: Polyalkylene glycols (PAG)
(2) Mineral oils: Naphthenic base oils and paraffinic base oils
(3) Synthetic oils: Alkylbenzene (AB) and Polyalphaolefine (PAO)
(4) Synthetic oils: Polyolesters (POE)
Oil sampling and analysis is recommended every six months.
If the following control criteria are not satisfied, replace the oil.
◆ Note that the water content of PAG shall be excluded from the above oil replacement criteria.
Refer to the Note *1 in the following table.
The analysis items and the criteria are shown in the following tables. Please note that these
management criteria may be changed without notice.
Table 4-1 Synthetic Oil (PAG)
ASTM color scale: 4.0 or less
(b) Total acid number (TAN)
Within ±10 % from that of fresh oil
2000 mass ppm or less Note1
(e) Degree of contamination
Degree of contamination measured by mass method (Millipore value)
shall be 15 mg/100 mL or less
Table 4-2 Mineral Oil and Synthetic Oil (AB, PAO)
ASTM color scale: 6.0 or less
(b) Total acid number (TAN)
Within ±15 % from that of fresh oil
(e) Degree of contamination
Degree of contamination measured by mass method (Millipore value)
shall be 15 mg/100 mL or less
Table 4-3 Synthetic Oil (POE)
ASTM color scale: 4.0 or less
(b) Total acid number (TAN)
Within ±10 % from that of fresh oil
(e) Degree of contamination
Degree of contamination measured by mass method (Millipore value)
shall be 15 mg/100 mL or less
Note 1: Synthetic oils (compatible with ammonia) are so highly hygroscopic that they can absorb
moisture at the time of sampling. In addition, the ammonia content they have absorbed may
be detected as the water content at the time of the analysis, making it difficult to precisely
measure the water content. Thus, use the criterion value only as a reference.