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EPA Practice Exam 2 Answers

Terms in this set (40)

Which of the following is NOT important to do before recharging any flammable hydrocarbon or HFO refrigerant into a system?
Add an odorant to the system to indicate a flammable refrigerant is being used
What are the characteristics of hydrofluoroolefins (HFO's)?
Non-ozone depleting, and have a low global warming potentials
Which of the following refrigerants is an HFO?
R-1234yf
Which of the following is a lawful use of HCFC-22?
Servicing existing R-22 systems
Which of the following refrigerants have an ozone depletion potential of more than zero?
R-123 and R-22
Which of the following refrigerants contains chlorine?
R-22
Which of the following factors affect the speed of systems dehydration?
The ambient temperature and amount of moisture in the system
What is a characteristic of a refrigerant oil that is hygroscopic?
It readily absorbs moisture
Which of the following is a "high-pressure refrigerant" under EPA's section 608 regulations?
R-410A
For which of the following refrigeration systems/appliances would it be permissible to use a passive recovery device for recovery of CFC's, HCFC's, and HFC's?
A domestic refrigerator
Permanent safety markings are NOT required on which of the following areas on household refrigerators use HC refrigerants?
On the exterior of the refrigerator
Equipment which is used to recover CFC, HCFC, and HFC refrigerant from small appliances for the purpose of disposal must meet what standard?
Recover 80% of the refrigerant with an inoperative compressor and 90% of the refrigerant with an operative compressor
The system dependent (passive) recovery process...
Recovers refrigerant in a non-pressurized container
Any person who opens an appliance containing a CFC, HCFC, or HFC for maintenance, service, or repair must have at least one self-contained recovery machine available for use. The exception to this rule are persons working on...
Small appliances
What can CFC and HCFC refrigerants decompose into at high temperatures (e.g. open flames, glowing metal surfaces, etc.)?
Hydrochloric and hydrofluoric acids
Which of the following are recommended safe work practices when recovering refrigerants?
Wear safety eyewear and butyl-lined gloves when connecting/disconnecting hoses
What should a technician do if the refrigerant in a recovery cylinder is suspected to be contaminated?
Turn refrigerant in for reclamation
After installing and opening a piercing access valve, the recovery procedure cannot begin if the system is at what pressure?
0 psig
It is generally recommended that piercing-type valves be used on which of the following tubing materials?
Copper and aluminum
What is the best use for testing with soap bubbles?
To pinpoint refrigeration leaks
What should systems that use R-407C be leak checked with?
Pressurized nitrogen and a trace amount R-407C
When first inspecting a hermetic system known to be leaking, you should look for...
Traces of oil
Which leak repair category does the EPA define as the refrigeration appliance used in retail food and cold storage warehouse sectors?
Commercial refrigeration
Which of the following is an indicator of a leak in a high-pressure system with a capillary tube?
Excessive superheat
Which of the following additions of refrigerant, when added to an appliance that contains 50 or more pounds of an ozone-depleting refrigerant, triggers the requirement to calculate the leak rate?
When topping off the system
What steps should be taken before using a recovery unit to remove a charge?
Service valve positions and recovery oil level should be checked, when applicable
What is the primary water source for a water-cooled recovery unit's condensing coil?
Local municipal water supply
Identify the best method to charge a system that has both an air-cooled condenser and evaporator with a nameplate charge of 80 lbs.
Liquid charge through the liquid-line service valve
Which of the following should be replaced if a system is opened for servicing?
Filter drier
When must the leak rate of an appliance using an ozone-depleting refrigerant be calculated?
When topping off or recharging a system due to a loss of charge
Continuous excessive moisture collection in the purge unit of a low-pressure refrigeration system could indicate what condition?
The condenser or chiller barrel tubes are leaking
Approximately how much refrigerant vapor is left in an average 350-ton R-123 chiller at 0 psig once all the R-123 liquid has been removed?
100 lbs.
To prevent freezing, when recharging an evacuated water-cooled chiller system with R-123, at what pressure or vacuum can liquid charging first begin?
20 psig
How long must a technician evacuating refrigerant from appliances with a full charge of more than 5 pounds and less than 50 pounds that are being disposed of keep records of the event?
3 years
ASHRAE Standard 15-2013 requires the use of room sensors and alarms to detect...
All refrigerant safety groups
Where does the purge unit on a centrifugal system take its suction?
Top of the condenser
What must be done after recovering the liquid refrigerant from a low-pressure chiller?
Recover the vapor refrigerant
Where does refrigerant go after it leaves the purge unit of a low-pressure centrifugal system?
The evaporator
What is meant by the term "high efficiency purge unit"?
Purge units that discharge a low percentage of refrigerant with the air they remove
What characteristic(s) of CFC's and HFC's make them more likely to reach the stratosphere than most other compounds containing chlorine?
They do not dissolve in water or easily break down in the atmosphere
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