Type II High-Pressure Systems Flashcards

A pressure-temperature (P-T) chart for R-22 is primarily used to:

Answer: Determine saturation temperature at a given pressure

A P-T chart relates system pressure to the refrigerant's saturation temperature.

An R-22 system reads a head pressure far above the saturation pressure for its condensing temperature. The most likely cause is:

Answer: Non-condensables or overcharge

Abnormally high head pressure points to non-condensables or an overcharge.

Which symptom most strongly suggests a low refrigerant charge in a high-pressure system?

Answer: Low suction pressure with high superheat

An undercharge causes low suction pressure and elevated superheat.

A leak detection method that uses an electronic device sensitive to halogenated refrigerants is called a:

Answer: Electronic leak detector

Electronic leak detectors sense halogenated refrigerant escaping from leaks.

When pressurizing a high-pressure system for leak testing, which gas is acceptable to use with refrigerant as a trace?

Answer: Nitrogen

Dry nitrogen is the safe pressurizing gas for leak testing.

Excessive subcooling at the condenser outlet of an R-22 system often indicates:

Answer: Overcharge or restricted liquid line

High subcooling commonly results from overcharge or a liquid-line restriction.

What does a sight glass showing bubbles in the liquid line typically indicate?

Answer: Low charge or restriction causing flash gas

Bubbles in the sight glass indicate flash gas from low charge or a restriction.