QUESTIONS AND ANSWERS (APRIL-JULY)
1. Which of the following always falls under the EPA definition for "major maintenance, service, or
repair?"
Replacing an oil filter
Replacing an expansion valve
Replacing a compressor
Replacing an accumulator
Replacing a compressor
2. Recovering refrigerant from a system in the vapor phase will minimize the loss of which of the
following?
water
oil
refrigerant
non-condensables
oil
AD
3. After system servicing, and recharging, why is refrigerant vapor reintroduced to the chiller before
refrigerant liquid?
Vapor charging increases pressure slowly, preventing failure of the rupture disk.
,Vapor charging is faster than liquid charging.
Liquid charging is more difficult to control than vapor charging.
Liquid charged into a deep vacuum will evaporate and may lower the temperature freezing water in the
heat exchanger tube bundle.
Liquid charged into a deep vacuum will evaporate and may lower the temperature freezing water in the
heat exchanger tube bundle.
4. In the event of a large release of CFC, HCFC, or HFC refrigerant in a contained area which of the
following is true?
Safety goggles and lined butyl gloves are sufficient.
Self-contained breathing apparatus (SCBA) or leaving the area is required.
Respiratory protection is not required.
Dust masks are sufficient.
Self-contained breathing apparatus (SCBA) or leaving the area is required.
5. 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?
1 day
10 days
30 days
45 days
30 days
,6. 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.
To reduce the amount of refrigerant in the oil.
7. What is a characteristic of a refrigerant oil that is hygroscopic?
It is a good lubricant.
It is crude oil and unrefined.
It readily absorbs moisture.
It can be left open to ambient air.
It readily absorbs moisture.
8. An appliance normally containing more than 50 pounds of R-22 refrigerant was found to have a 35%
annual leak rate. After the repair, how many successful verification tests are required?
One. Performed before the appliance is recharged.
Two. The first performed before the appliance is recharged, and the second performed after the
appliance returns to normal operating conditions.
One. Performed once the appliance returns to normal operating conditions.
Three. The first performed before the appliance is recharged, the second performed after the appliance
returns to normal operating conditions, and the third performed three months later.
Two. The first performed before the appliance is recharged, and the second performed after the
appliance returns to normal operating conditions.
, 9. Which of the following should be replaced if a system is opened for servicing?
Filter drier
Thermostat
Metering device
Crankcase heater
Filter drier
10. What must a system owner do, once the threshold leak rate has been exceeded on any low-pressure
system using an ozone depleting refrigerant?
Retire the appliance the following year.
Repair all of the leaks and submit a report about the repair to the EPA.
Immediately mothball the appliance until it is retrofitted.
Repair the appliance enough to bring the leak rate below the threshold, retrofit, or retire the appliance.
Repair the appliance enough to bring the leak rate below the threshold, retrofit, or retire the appliance.
11. When could a reciprocating compressor be damaged if energized?
When the discharge service valve is closed.
When the suction service valve is open.
When the discharge service valve is open.
When the demand for cooling is at a steady state.
When the discharge service valve is closed.