USCG Exam PracticeRefrigeration cycle and components
During operation of a marine refrigeration plant, the high-pressure cutout trips. Which of the following conditions would NOT be a likely cause?
- A. Fouled or scaled condenser tubes
- B. Loss of seawater flow to the condenser
- C. Non-condensable air trapped in the condenser shell
- ✓ Low refrigerant charge in the systemCorrect
Why D is correct
A low refrigerant charge causes low suction pressure and low head pressure, which would trip the low-pressure cutout, not the high-pressure cutout. Fouled condenser tubes, loss of cooling water, and non-condensable air all impair heat rejection, raising high-side pressure until the high-pressure cutout operates.