CORE
R-407C pressures and temperatures are similar to:
A. R-22
B. R-12
C. R-502
D. R-134a
A. R-22
On a system with an operating compressor, recovery equipment must be capable of recovering;
A. 95% of the refrigerant or achieving 5 inches of vacuum.
B. 90% refrigerant or achieving 4 inches of vacuum.
C. 80% refrigerant or achieving 4 inches of vacuum.
D. 100% refrigerant or achieving 0 inches of vacuum.
B. 90% refrigerant or achieving 4 inches of vacuum.
Unless plans are made to replace a system with a leak rate that exceeds the maximum leak rate, repairs must be made within;
A. 30 days.
B. 45 days.
C. 60 days
D. 90 days.
A. 30 days.
Where is refrigerant added to a low-pressure system during the charging process?
A. The access valve on the purge unit entering the condenser.
B. The lowest access point on the system such as the condenser charging valve.
C. The highest access point on the system such as the evaporator inlet valve.
D. The lowest access point on the system such as the evaporator charging valve.
D. The lowest access point on the system such as the evaporator charging valve.
In a low-pressure chiller, air and other non-condensables collect at the;
A. bottom of the compressor.
B. top section of the condenser.
C. bottom of the evaporator.
D. header before the metering device.
B. top section of the condenser.
Whenever possible, to avoid fractionation, charging of a refrigeration system incorporating a near-azeotropic blend should be done with:
A. Liquid refrigerant
B. A scroll compressor
C. R-22
D. A yellow and gray recovery cylind
A. Liquid refrigerant
Small appliances are equipped with a straight piece of tubing (process stub) that is used;
A. As the installation location for a piercing-type access valve.
B. To help the technician measure system subcooling.
C. As a p-trap to help capture system contaminants and debris.
D. To help the technician measure evaporator superheat.
A. As the installation location for a piercing-type access valve.
A high-pressure appliance containing 210 lbs. of R-407C refrigerant must be evacuated (recovered) to a level of;
A. 15 inches of vacuum
B. 10 inches of vacuum
C. 4 inches of vacuum
D. 0 inches of vacuum
B. 10 inches of vacuum
Which organization establishes the refrigerant safety group standard?
A. AHRI
B. UL
C. ASHRAE
D. ASE
C. ASHRAE
EPA regulations require that all Industrial Process Refrigeration (IPR) systems containing more than 50 pounds of refrigerant MUST be repaired when the annual leak rate exceeds;
A.10 %
B. 20 %
C. 30 %
D. 40 %
C. 30 %
Liquid lines used with R-22:
A. May only be used with R410A in dry climates
B. May never be used with R-410A
C. May be used with R-410A if sized and properly cleaned
D. May be used with R-410A without additional considerations
C. May be used with R-410A if sized and properly cleaned
Applying heat, with a heat gun, to the compressor;
A. can help free-up a bound compressor motor.
B. can help vaporize any trapped liquid refrigerant during recovery.
C. can help remove trapped refrigerant vapor during recovery.
D. can aid in isolating and pinpointing a refrigerant leak.
B. can help vaporize any trapped liquid refrigerant during recovery.
A new split system should be checked for leaks by;
A. pressurizing the system with a few ounces of HCFC-22 and compressed air.
B. pressurizing the system with a few ounces of CFC-12 and an inert gas.
C. releasing the factory refrigerant charge in the condensing unit.
D. pressurizing the system with a few ounces of system refrigerant and an inert gas.
D. pressurizing the system with a few ounces of system refrigerant and an inert gas.
After all the liquid has been removed from an average 350-ton, low-pressure appliance, approximately how much vapor refrigerant remains in the system?
A. 100 pounds
B. 150 pounds
C. 350 pounds
D. 45 pounds
A. 100 pounds
Which of the following is an example of a non-condensable?
A. Moisture
B. Air
C. R-12
D. R-134a
B. Air
If R-410A is ingested:
A. Immediately inject trioxide compound
B. Drink milk
C. Do not induce vomiting
D. Induce vomiting
C. Do not induce vomiting
When pressurizing a system with nitrogen you should;
A. never exceed 3.5 times the high side pressure rating.
B. charge through a pressure regulator.
C. install a relief valve in the line downstream from the pressure regulator.
D. Both B and C.
D. Both B and C.
When using a recovery unit on a system containing 100 lbs. of R-410A it must be evacuated to;
A. 0 inches of Mercury
B. 4 inches of Mercury
C. 10 inches of Mercury
D. 15 inches of Mercury
A. 0 inches of Mercury
When charging a low-pressure system, refrigerant should be introduced to the system as a vapor to raise the system's saturation temperature to a minimum of;
A. 0 degrees.
B. 36 degrees.
C. 40 degrees.
D. 70 degrees.
B. 36 degrees.
When filling a charging cylinder with a regulated refrigerant;
A. The refrigerant vapor that is vented off the top of the cylinder must be recovered.
B. The refrigerant must be added to the cylinder in the vapor phase to reduce losses.
C. The refrigerant being added to the cylinder must be weighed in to ensure accuracy.
D. The refrigerant vapor can be vented off the top of the cylinder as a deminimus release.
A. The refrigerant vapor that is vented off the top of the cylinder must be recovered.
Which refrigerant has an ozone depletion potential of zero?
A. R-22
B. HCFC-22
C. CFC-11
D. R-134A
D. R-134A
If regulations change after the technician becomes certified;
A. The technician must re-take the certification exam.
B. An additional fee must be paid to the EPA by the technician.
C. The technician is responsible for complying with any changes to the regulations.
D. There are no additional compliance requirements for the technician.
C. The technician is responsible for complying with any changes to the regulations.
All HVAC/R systems must be protected by a;
A. Low-pressure switch
B. High-pressure switch
C. Compressor impedance overload
D. Pressure relief valve
D. Pressure relief valve
Under ASHRAE Standard 34, R-134a is classified as;
A. A1
B. A2
C. B1
D. B2
A. A1
A liquid changes to a vapor by absorbing:
A. Sensible heat
B. Superheat
C. Moisture
D. Latent heat
D. Latent heat