Which of the listed reasons could cause...

🔍 Key Concepts

• Refrigeration cycle basics – what should normally be cold vs. warm (suction line, liquid line, compressor body) • Effect of expansion valve operation on temperature/pressure in the evaporator and suction line • Difference between low refrigerant flow, no refrigerant flow, and excessive refrigerant flow

💭 Think About

• Think about what has to happen on the low‑pressure (suction) side of the system for the line to get so cold that moisture in the air will freeze on it. • Which condition would allow too much liquid or excessive cooling in the evaporator and suction line, rather than starving it? • For each choice, ask yourself: does this make the evaporator/suction line colder than normal, warmer than normal, or stop flow almost completely?

✅ Before You Answer

• Identify which option would most likely cause flooding of the evaporator/suction line rather than starving it. • Eliminate any option that would obviously reduce refrigerant flow to the evaporator to near zero (no cooling, therefore no frost). • Consider what happens to suction pressure and line temperature when the expansion valve fails in different positions.

Which of the listed reasons could cause frost to form on the suction line of a refrigeration compressor?

Shortage of refrigerant in the system.

Expansion valve is stuck open.

Liquid line service valve is closed.

Condenser cooling water temperature is too high.

🔍 Key Concepts

💭 Think About

✅ Before You Answer