Are you a homeowner or building manager?
Find a Contractor »

Tech Challenge – September 2021

Posted on:

A logo of a yellow, red, blue, and green rubix cube with one square out of place and "Tech Challenge" written beneath it

A medium temperature beer cooler utilizing R-134a with a TXV metering device and liquid receiver, has a customer complaint of warm beer. The symptoms at the convenience store confirm inadequate cooling and the compressor appears to be short cycling on the high- or low-pressure control. What are the “possible causes,” (Note: There is only one problem intended) with the following measured/calculated conditions on this field service check sheet? 

Field Service Check Sheet 

  • Compressor Discharge                      Temp. 225 deg. F. 
  • Condensing Press. /Temp.                255 psig / 88 deg. F. 
  • Condensing Outlet Temp.                 88 deg. F. 
  • Condenser Sub cooling                     30 deg. F. 
  • Condenser Split                                  43 deg. F. 
  • Entering Feed Device Temp.             85 deg. F. 
  • Evaporator Press. /Temp.                 22 psig / 25 deg. F. 
  • Evaporator Outlet Temp.                  40 deg. F. 
  • Evaporator Superheat                       15 deg. F. 
  • Compressor Inlet Temp.                   68 deg. F. 
  • Total S. H.                                            43 deg. F. 
  • Ambient Temp.                                   75 deg. F. 
  • Room/Box Temp.                               50 deg. F. 
  • Compressor Volts                              240 V. 
  • Compressor Amp. Draw                   Normal/High 

Check back on October 1, 2021 for the answer to this issue’s Tech Challenge.

Posted In: ACCA Now, Tech Challenge

Looking for an ACCA QA Accredited Contractor?

Are you a homeowner or building manager?


join now

PLUS It's Risk Free!