After refrigerant liquid has been recovered from the appliance, any remaining vapor is;

• purged to the atmosphere.

• isolated in the appliance.

• pumped into appliance receiver.

• removed by the recovery system.

An initial leak verification test failed after repairing a leak in a rack refrigeration system for a supermarket using an HCFC refrigerant. What would be the next step(s)?

• Immediately retrofit or retire the appliance.

• Conduct additional repairs within the 30-day repair window or mothball the appliance.

• Conduct a follow-up verification test.

• Report the amount of refrigerant added to the system to the EPA.

Every refrigerating system must be protected by which of the following?

• A pressure relief device.

• A properly located stop valve.

• A low pressure control.

• A refrigerant receiver.

For what refrigerant is an equipment room refrigerant detector NOT required under ASHRAE Standard 15 provided the mechanical ventilation system in the machinery is run continuously?

• R-134a

• R-404A

• R-410A

• R-717

How long do owners or operators of an appliance with a full charge of 50 or more pounds of ozone­ depleting refrigerant have to retire an appliance if the replacement uses a refrigerant that is exempt from the venting prohibition?

• 3 months

• 6 months

• 12 months

• 18 months

How long must an HVAC servicing company keep records for each disposed appliance with a charge between 5 and 50 pounds?

• 1 year

• 3 years

• 5 years

• 10 years

Identify the best method to charge a system that has both an air-cooled condenser and evaporator with a nameplate charge of 80 pounds.

• Vapor charge through the suction service valve.

• Liquid charge through the discharge service valve.

• Liquid charge through the suction service valve.

• Liquid charge through the liquid-line service valve.

Pressure relief valves can only be installed;

• in series.

• in parallel.

• vertically.

• horizontally.

Starting in 2019, what leak rate triggers the EPA requirement that commercial refrigeration systems containing 50 pounds or more of R-22 be repaired?

• 10%

• 20%

• 30%

• 35%

What are refrigeration and air-conditioning compressor heaters used for?

• To reduce the amount of refrigerant in the oil.

• To prevent refrigerant vaporization.

• To reduce the amount of entrained water in the receiver.

• To prevent acid pitting.