USCG Exam PracticeRefrigeration and air conditioning
A refrigeration system sight glass shows a steady stream of bubbles in the liquid line. What condition does this most likely indicate?
- A. The system is overcharged and head pressure is excessive
- B. Non-condensable gas has collected in the evaporator
- ✓ The system is undercharged or there is a restriction in the liquid lineCorrect
- D. The condenser tubes are fouled, causing high discharge temperature
Why C is correct
NAVEDTRA 14075 §6-3 states the sight glass lets the operator see whether the liquid is solid (fully charged) or full of bubbles, and identifies bubbles as indicating an undercharged system or a restriction. An overcharge would raise head pressure but would not produce bubbles in the liquid line.
Cited:NAVEDTRA 14075 §6-3