Tecumseh R410A Iii. System Design, Filter-Driers, I. REFRIGERANT PROPERTIES Cont’d, AMiscibility

DRAFT COPY

DATE: September 2011 Rev. 1 REFERENCE DOCUMENT NO. RD-0027-E

I. REFRIGERANT PROPERTIES (Cont’d)

B)The solubility of water in R410A is comparable to that of water in R22. It is necessary to keep the system dry. See Section II, B.

C)Extensive investigation and testing has been conducted to determine that R410A is compatible with all materials used in Tecumseh compressors designed for use with R410A refrigerant.

C)Compatibility

Extensive investigation and testing have been conducted by Tecumseh Products Company to determine that the polyol ester and polyvinyl ether lubricants approved by Tecumseh are compatible with all materials used in Tecumseh hermetic compressors. Contact your Tecumseh sales representative for the latest list of approved oils. (Policy Bulletin No. 105)

II.SYNTHETIC LUBRICANTS: POLYOL ESTERS (POEs) and POLYVINYL ETHERS (PVEs)

A)Miscibility

1.Miscibility is the ability of the lubricant and the refrigerant to mix. This miscibility is a very important factor in providing proper heat transfer and in returning lubricant to the compressor in a refrigeration system over its range of operating temperatures.

2.R410A and Mineral oils (MO) are not miscible

3.Polyol Ester (POE) as well as Polyvinyl Ether (PVE) oils and R410A are miscible.

B)Moisture

1.Polyol Ester and Polyvinyl ether oils are 100 times more hygroscopic (ability to absorb moisture) than MO or SA oils. This moisture is difficult to remove even with heat and vacuum.

2.Utmost care must be taken to prevent moisture from getting into the refrigeration system. Do not leave the compressor or system open to the atmosphere for longer than 10 minutes maximum. The preferred method of assembly would be to remove system component plugs and caps just prior to brazing. The maximum system moisture content after completing system processing should be 80 PPM. After running the system with the appropriate filter-drier installed, the system moisture level should be 50 PPM or less. These levels are based on measuring moisture in liquid refrigerant samples taken from the system.

3.Always use an appropriate filter-drier in the system when using R410A. (See section on FILTER-DRIERS.)

III. SYSTEM DESIGN

A)Compressor Selection

Tecumseh is continuing to test and approve R410A compressors with the compatibility of oil, refrigerant, and materials in mind. These compressors will have the letter “B” as the refrigerant designator, e.g. RGA5512BXA.

B)Expansion Valve Selection

Expansion valve manufacturers have designed product specifically for use with R410A. Consult them for their recommendations.

C)Capillary Tubes

R410A requires approximately 15% less capacity for the metering device compared to R22. This information can be used when selecting the appropriate capillary tube.

D)Filter-Driers

Tecumseh requires that an appropriate filter-drier be used on every R410A system. (See section on FILTER-DRIERS.)

FILTER-DRIERS

A)Synthetic POE lubricants used with R410A are prone to hydrolyze with moisture resulting in the formation of acids. Tecumseh requires that an appropriate filter-drier be used in every R410A application.

B)Molecular sieve filter-driers which are compatible with R410A should be used..

C)For specific filter-drier selection, contact your filter- drier supplier.

© 2011 Tecumseh Products Company. All rights reserved. Page 3 of 4