Refrigerants 8

The best method of leak checking is when the refrigeration system is ____.

• a. in a vacuum

• b. open to the atmosphere

• c. operating with all fans activated

• d. standing with dry nitrogen pressure of 150 psig in the system

Tags

NGSS.HS-ETS1-3

When moisture is present in a refrigeration system, it will react with the refrigerant and the oil to form ____.

• a. carbon dioxide

• b. acid

• c. carbon monoxide

• d. carbolic acid

Noncondensable gases ____.

• a. are desirable in a refrigeration system

• b. are undesirable in a refrigeration system

• c. condense readily under normal atmospheric conditions

• d. help in pulling a vacuum

To pull a vacuum means to ____.

• a. raise the pressure in a refrigeration system

• b. lower the pressure in a refrigeration system below atmospheric

• c. allow refrigerant to escape into the atmosphere

• d. condense the gas in the system

A compound gauge ____.

• a. indicates pressures above 14.696 psia

• b. indicates pressures in inches Hg below atmospheric pressure

• c. is one of two gauges on a typical gauge manifold

• d. All of the above.

A micron gauge is used to measure ____.

• a. atmospheric pressures at high altitudes

• b. atmospheric pressures at sea level

• c. absolute pressures below 1 mm Hg

• d. high pressure in a refrigeration system

At what pressure range does the technician valve off the vacuum pump when evacuating to a deep vacuum?

• a. 200 to 100 microns.

• b. 300 to 100 microns.

• c. 300 to 200 microns.

• d. 500 to 300 microns.

Which of the following represents the lowest vacuum?

• a. 10 psia.

• b. 5 in. Hg vacuum.

• c. 5 psig.

• d. 1000 microns.

A multiple evacuation means that ____.

• a. you connect three vacuum pumps simultaneously to a refrigeration system and pull a vacuum

• b. you pull a vacuum on three different systems at the same time

• c. you pull a vacuum on a refrigeration system more than once, allowing refrigerant or nitrogen into the system between each procedure

• d. there must be more than one system operating before a vacuum can be pulled

Moisture in a liquid state must be ____ before it can be removed with a vacuum pump.

• a. vaporized

• b. condensed

• c. cooled

• d. solidified

Tags

NGSS.MS-PS1-4