24 Capacity Test 3 Error (Check Alarm)

Thermo King Alarm Code

Description

Corrective Action

Capacity Test 3 Error (Check Alarm) Occurs during Pretrip (PTI) test only. Difference between supply and return air temperature is too high with Stepper valve almost closed and high speed evaporator fans (more than 1.5 C [2.7 F]). Indicates: Defective Stepper valve Incorrect location of supply or return air sensor Defective supply or return air sensor Expansion valve open too much Incorrect refrigeration system operation Container/side panels defective, damaged or leaking

Enter Manual Function Test and start the following components: Condenser fan, evaporator fan (high), compressor and compressor 25%. Check to be sure the Stepper valve closes. Check the supply and return air sensor connections. Check the supply and return air sensor calibration. Check expansion valve superheat setting.