Converting from Standard to Low Leaving Water Temperatures RTAA

Issue:

Converting RTAA from standard to low leaving water temperatures

Resolution:

An RTAA purchased for standard leaving water temperatures (60-40 deg F) can be converted to produce low leaving water temperatures (<40 deg F).

To convert the RTAA, the settings for the Low Evaporator Temperature Cutout and Low Water Temperature Cutout need to be adjusted. These setting can be referenced in the RTAA IOM's.

• For RTAA 130-400, use IOM RTAA-IOM-3 page 102
• For RTAA 70-125, use IOM RTAA-SVX01A-EN page 97

• The refrigerant piping between the RTUA and air-cooled condenser should be evaluated to ensure the piping is sized correctly for the lower LWT
• This does not apply to the RTWA ordered at comfort cooling temperatures.  For low temperature and high condenser applications, the compressors are different and an oil cooler may have to be installed

It is best to contact the Trane Field Modifications Group in La Crosse. Non-Trane customers should contact their local Trane parts counter first and then the parts counter can contact the Field Modifications Group.

Notes:

Resource Available:

• Tech TV Video(s):
  • N/A
• Reference Literature: (Electronic copies can be pulled from e-library at Trane Residential (tranetechnologies.com))
  • IOM: RTAA-IOM-3 and RTAA-SVX01A-EN
  • Service Guide: 
• Other:
  • N/A

Changes:

Other Question/Problem/Cause Statements:

• Converting RTAA from standard to low leaving water temperatures

Facts:

• Air-Cooled Chiller (Pueblo) (RTAA 130-400 Ton)
• Air-Cooled Chiller (Pueblo) (RTAA 70-125 Ton)

Document Identifier: DOC-77393, DOC-82601, DOC-84173, and DOC-90229