TYPE 2.9 Flashcards
When first inspecting a hermetic system known to be leaking, you should look for; A. frost on the tubing. B. puddles of refrigerant. C. particles of filter drier core. D. traces of oil.
D. traces of oil
When a trace gas becomes absolutely necessary, which of the available gases should be used to help
locate a leak?
A. Nitrogen with HCFCR-22.
B. R-22 due to its universal system compatibility and its miscibility with various oils.
C. Nitrogen with a trace amount of the system’s design refrigerant.
D. Nitrogen with HFC R-410A.
C. Nitrogen with a trace amount of the system’s design refrigerant
A chiller for comfort cooling that contains 50 pounds or more of R-123 is leaking. Starting in 2019, at
what leak rate does the EPA require that the equipment be repaired?
A. 5%
B. 10%
C. 15%
D. 20%
B. 10%
A comfort-cooling appliance containing 50 pounds or more of R-22 is found to be leaking beyond the
applicable leak rate threshold. Unless granted additional time, how many days do you have to repair the
leak and conduct the initial leak verification test?
A. 1 days
B. 10 days
C. 30 days
D. 45 days
C. 30 days
How long must owners and operators of regulated appliances normally containing 50 or more pounds of
HCFC refrigerant keep records of leak inspections, initial leak verification and follow-up verification tests?
A. 2 years
B. 3 years
C. 5 years
D. Life of the appliance
B. 3 years
After refrigerant liquid has been recovered from the appliance, any remaining vapor is; A. purged to the atmosphere. B. isolated in the appliance. C. pumped into appliance receiver. D. removed by the recovery system.
D. removed by the recovery system
Why could a recycling or recovery machine that uses a hermetic compressor overheat when drawing
deep vacuums?
A. It runs faster than other equipment with oil less compressors.
B. The motor relies on the flow of refrigerant through the compressor for cooling.
C. It has a higher compression ratio limit than other equipment.
D. The oils used in hermetic compressors are a lower viscosity than the oils used in other equipment
B. The motor relies on the flow of refrigerant through the compressor for cooling.
What should be done before transferring refrigerant to an empty cylinder? A. The refrigerant should be chilled. B. The refrigerant should be mixed. C. The cylinder should be heated. D. The cylinder should be evacuated
D. The cylinder should be evacuated.
What steps should be taken before using a recovery unit to remove a charge?
A. The refrigerant should be tested for acid.
B. The recovery unit should be purged with nitrogen.
C. The recovery unit oil should be changed and recovery cylinder evacuated.
D. Service valve positions and recovery oil level should be checked, when applicable
C. The recovery unit oil should be changed and recovery cylinder evacuated.
When should refrigerant be removed from the condenser outlet?
A. When the condenser is below the receiver.
B. When the condenser is on the roof.
C. When the condenser is inoperative.
D. When the evaporator has a small leak.
A. When the condenser is below the receiver.
An operating unit that has a receiver/storage tank requires refrigerant system service. When servicing
the unit;
A. the compressor should be valved off.
B. liquid refrigerant should be recovered last.
C. refrigerant should be pumped down to and isolated in the receiver.
D. a gauge pressure of “Ol/psi should be achieved by venting.
C. refrigerant should be pumped down to and isolated in the receiver
How long must an HVAC servicing company keep records for each disposed appliance with a charge between 5 and 50 pounds? A. 1 year B. 3 years C. 5 years D. 10 years
B. 3 years
Which ofthe following statements about recycling and recovery equipment is FALSE?
A. It must be tested by an EPA-approved third party
B. Purchases of such equipment must be reported to the EPA
c. It must be equipped with low-loss fittings
D. Equipment designed to recover flammable refrigerant must meet a specific UL safety standard
B. Purchases of such equipment must be reported to the EPA
You are changing out the compressor of a system containing 40 pounds of R-404A. In addition to
isolating the compressor, which of the following procedures should you follow?
A. Simply remove the compressor and cap the ends.
B. Evacuate the isolated section of the system to atmospheric pressure, then remove the compressor.
C. Evacuate the isolated section of the system to 0 psig and if system pressure does not rise after a few
minutes, remove the compressor.
D. Evacuate the isolated section of the system to 5 inches of vacuum and when the system’s pressure
rises out of the vacuum, remove the compressor.
C. Evacuate the isolated section of the system to 0 psig and if system pressure does ntit rise after a few
minutes, remove the compressor.
What should be done after reaching the required recovery vacuum on an appliance?
A. Immediately disconnect the recycling or recovery equipment, and open the system for service.
B. Wait for at least a few minutes to see if the system pressure rises.
C. Break the vacuum with nitrogen and open the system for service.
D. Pressurize the system with nitrogen and perform a leak check.
. Wait for at least a few minutes to see if the system pressure rises.