53 High Pressure Switch Off Error MP4000

Description 

High Pressure Switch Off Error 

• Occurs during pretrip (PTI) test only. 
• Compressor does not stop during high pressure cutout switch test. 
• Indicates: 
• Faulty compressor contactor or control circuit. 
• Low refrigerant charge. 
• Defective high pressure cutout switch. 
• Strong winds causing cooling of condenser coil in low ambient conditions. 

Corrective Action 

• Check discharge and suction pressure gauge readings and check refrigerant charge. 
• Enter Manual Function Test menu. 
• Start the following components together: compressor 100 percent, compressor and evaporator fans (high). Discharge pressure should increase and compressor should stop at 2250 kPa, 22.5 bar, 326 psig (high pressure cutout switch opens).