158)
158)
Third–party testing for recovery units has been required since:
A)
July 1, 1992.
B)
November 15, 1993.
C)
November 14, 1994.
D)
November 15, 1995.
Answer:
B
Explanation:
159)
159)
How is recovering into a receiver accomplished?
A)
The Schrader valves are replaced with receiving hoses.
B)
A receiver is placed over a tube after it has been pierced.
C)
The refrigerant is pumped into the receiver with the king valve closed.
D)
A plastic recovery device is emptied into a receiver.
Answer:
C
Explanation:
160)
160)
Why is knowledge regarding the recovery level for Type II systems with 200 lb or more of R–22
not important for most technicians?
A)
Type II recovery levels are optional by law.
B)
Enforcement rates for recovery levels are low.
C)
Few systems are this small.
D)
Few systems are this large.
Answer:
D
Explanation:
161)
161)
How do the recovery levels for Type III equipment differ from recovery levels for other types of
equipment?
A)
They require lower vacuums than for other types.
B)
They are all optional to attempt.
C)
They are all the same amount.
D)
They are all higher than for other types.
Answer:
A
Explanation:
41
162)
162)
Releases of refrigerant that result from connecting or disconnecting gauge hoses:
A)
Must be prevented by using special low–loss adapters.
B)
Are punishable under a special reduced–penalty provision for small infractions.
C)
Are permissible under the EPA regulations.
D)
Must be prevented by recovering the refrigerant from the gauge hoses each time they are
connected.
Answer:
C
Explanation:
163)
163)
A self–contained recovery device:
A)
Is used with systems that are not connected to the power grid.
B)
Relies on the system from which the refrigerant is being recovered for its operation.
C)
Does not rely on the system from which the refrigerant is being recovered for its operation.
D)
Can only be used on systems that are sold by independent distributors.
Answer:
C
Explanation:
164)
164)
A “de minimus” release is:
A)
Less than 10 percent of the system charge.
B)
Less than 1 percent of the system charge.
C)
The quantity of refrigerant released in the course of making a good–faith attempt to
recapture and recycle or safely dispose of refrigerant.
D)
The minimum amount of refrigerant release required by the EPA before they prosecute a
case.
Answer:
C
Explanation:
42
165)
165)
When using a recovery machine manufactured after November 15, 1993, the recovery level for
Type II systems containing over 200 lb of R–22 refrigerant is:
A)
0 psig.
B)
4 in Hg vacuum.
C)
10 in Hg vacuum.
D)
15 in Hg vacuum.
Answer:
C
Explanation:
166)
166)
The international agreement that established target dates for the phaseout of ozone–depleting
substances was the:
A)
Montreal Protocol.
B)
Treaty of Versailles.
C)
International EPA Consortium.
D)
UN Accord.
Answer:
A
Explanation:
167)
167)
When using a recovery machine manufactured after November 15, 1993, the recovery level for
Type II systems containing over 200 lb of R–12 refrigerant is:
A)
0 psig.
B)
4 in Hg vacuum.
C)
10 in Hg vacuum.
D)
15 in Hg vacuum.
Answer:
D
Explanation:
168)
168)
Why should some refrigerants NOT be recovered?
A)
Older refrigerants have mostly dissipated already.
B)
Type III refrigerant cannot be reused.
C)
Many machines hold too little refrigerant to recover.
D)
Older machines may hold toxic chemicals.
Answer:
D
Explanation:
43
169)
169)
Why is it necessary to use special methods when recovering from Type III systems?
A)
Most of these systems are very small–scale.
B)
Most of these systems are very low pressure.
C)
Most of these systems are chillers.
D)
Most of these systems utilize toxic chemicals.
Answer:
B
Explanation:
170)
170)
Which legal framework calls for a prohibition on venting ozone–depleting refrigerants,restrictions
on the sale of ozone–depleting refrigerants, and certification of recycling and recovery equipment
and technicians?
A)
Title VI of the Clean Air Act
B)
Kyoto Accord
C)
Geneva Convention
D)
Montreal Protocol
Answer:
A
Explanation:
171)
171)
According to EPA regulations, which individuals are required to keep records?
A)
Technicians and employers
B)
Employers and equipment owners
C)
Technicians and wholesalers
D)
Technicians, employers, wholesalers, and equipment owners
Answer:
D
Explanation:
172)
172)
Which statement best summarizes the logic behind the creation of the Montreal Protocol?
A)
Ozone depletion is an issue best left to third–world countries.
B)
The hole in the ozone layer is not related to human activities.
C)
The ozone is too large an issue for any single nation.
D)
Ozone protection is best left as a private–sector matter.
Answer:
C
Explanation:
44
173)
173)
The recovery level for Type III systems using a recovery device manufactured before November
15, 1993, is:
A)
25 in Hg vacuum.
B)
0 psig.
C)
4 in Hg vacuum.
D)
25 mm absolute pressure.
Answer:
A
Explanation:
174)
174)
Why is the Montreal Protocol significant?
A)
It does not require government action to achieve its goals.
B)
It has the support of almost every country in the world.
C)
Its benchmark goals have all been met.
D)
It has led to a complete ban on ozone–depleting products.
Answer:
B
Explanation:
175)
175)
Refrigerant that has been removed in any condition from an appliance and stored in an external
container without necessarily testing or processing it in any way is considered:
A)
Recovered refrigerant.
B)
Recycled refrigerant.
C)
Reclaimed refrigerant.
D)
Virgin refrigerant.
Answer:
A
Explanation:
176)
176)
Leaks in industrial process cooling systems must be repaired if they have an annual leak rate of:
A)
10 percent of the charge per year.
B)
15 percent of the charge per year.
C)
25 percent of the charge per year.
D)
35 percent of the charge per year.
Answer:
D
Explanation:
45
177)
177)
What is a general formula for calculating the effect of temperature on a holding charge?
A)
4005 × square root of temperature difference
B)
Add or subtract the temperature difference from the starting pressure.
C)
P2 = P1 × delta T
D)
New temperature/starting temperature ×
starting pressure
Answer:
D
Explanation:
178)
178)
Why has the use of halide torches in leak detection decreased in popularity?
A)
It is a very expensive method.
B)
It has harmful environmental implications.
C)
It does not work with most modern refrigerants.
D)
It has been banned by many states.
Answer:
C
Explanation:
179)
179)
How is ultrasound used in leak detection?
A)
It amplifies the sound of a leakage.
B)
It causes the formation of bubbles near a leak.
C)
It allows for a visual close–up of the system.
D)
It makes exiting gases visible.
Answer:
A
Explanation:
180)
180)
Why is it important to limit the pressure in a chiller?
A)
Chiller system hoses easily burst.
B)
Pressure gauges cannot detect high pressure levels.
C)
Chiller disks have low rupture thresholds.
D)
Heavy pressure will cause valve damage.
Answer:
C
Explanation:
46
181)
181)
What is one of the disadvantages of using dyes in leak detection?
A)
They are highly sensitive to small coolant amounts.
B)
They are difficult to clean from the affected area.
C)
They gradually damage the overall system.
D)
They do not reveal precise locations.
Answer:
B
Explanation:
182)
182)
A refrigeration system dataplate states that the low–side test pressure is 150 psig. This means that:
A)
The low side should operate with a pressure of 150 psig at all times.
B)
The low–side pressure should be 150 psig when the system is running its self–test.
C)
The low–side pressure will be 150 psig when the system is operating at design conditions.
D)
The low side should not be pressurized above 150 psig.
Answer:
D
Explanation:
183)
183)
Which leak detectors can be used with systems that are only charged with nitrogen?
A)
Heated diode electronic detectors
B)
Ultrasonic leak detectors
C)
Infrared detectors
D)
Corona discharge electronic detectors
Answer:
B
Explanation:
184)
184)
Why does a pressure drop not necessarily indicate a refrigerant leak?
A)
It may be indicating system shutoff.
B)
It may be indicating atmospheric pressure.
C)
It may be indicating temperature change.
D)
It may be indicating nitrogen presence.
Answer:
C
Explanation:
47
185)
185)
Why might leak testing with nitrogen be preferable to using R–22?
A)
System safety
B)
Postdetection clean–up
C)
Environmental concerns
D)
Refrigerant recovery
Answer:
C
Explanation:
186)
186)
In leak detection, R–22 is used in conjunction with which of the following?
A)
Electronic detection
B)
Soap bubbles
C)
Ultrasound
D)
Visual inspection
Answer:
A
Explanation:
187)
187)
The preferred method for raising the pressure of a low–pressure chiller in order to test for leaks is:
A)
Adding more refrigerant.
B)
Circulating warm water through the chiller.
C)
Adding nitrogen to the evaporator.
D)
Charging the chiller with R–410A.
Answer:
B
Explanation:
188)
188)
Why does the compressor on a leaking system become overheated?
A)
There is too much coolant overworking it.
B)
It is an overworked system.
C)
There is a reduced amount of coolant.
D)
It is a result of unbalanced lines.
Answer:
C
Explanation:
48
189)
189)
When calculating the effect of temperature change on a standing charge:
A)
Always use Fahrenheit an gauge pressure.
B)
Always use Celsius and kilopascals.
C)
Always use absolute pressure and temperature.
D)
Any pressure and temperature scale will work.
Answer:
C
Explanation:
190)
190)
Why does the EPA NOT require that all leaks be fixed?
A)
Type III systems are exempt.
B)
Publicly owned systems are exempt.
C)
Residential units are always exempt.
D)
Charges under 50 lb are exempt.
Answer:
D
Explanation:
191)
191)
A technician determines that an air–conditioning system holding 50 lb of refrigerant lost one lb of
refrigerant in a month. Does the EPA require the leak to be repaired?
A)
No, because 1 lb is not 35 percent of 50
B)
Yes, because leaking 1 lb in a month is a leak rate of 24 percent per year
C)
No, because systems that only hold 50 lb are exempt
D)
No, because 1 lb is not 15 percent of 50
Answer:
B
Explanation:
192)
192)
What refrigerants can be detected with a halide torch?
A)
CFCs and HCFCs
B)
CFCs
C)
HCFCs
D)
Hydrocarbon refrigerants
Answer:
A
Explanation:
49
193)
193)
Leaks in air–conditioning systems must be repaired if they have an annual leak rate of:
A)
10 percent of the charge per year.
B)
15 percent of the charge per year.
C)
25 percent of the charge per year.
D)
35 percent of the charge per year.
Answer:
B
Explanation:
194)
194)
How does one detect a leak in a low–pressure system?
A)
Slower recovery rates
B)
Full system shutdowns
C)
An extended purging operation
D)
High pressure increases
Answer:
C
Explanation:
195)
195)
Why are heated diode leak detectors better than corona discharge leak detectors?
A)
Heated diode leak detectors can detect greater amounts of coolant.
B)
Heated diode leak detectors use infrared lights in leak detection.
C)
Heated diode leak detectors are less expensive to replace.
D)
Heated diode leak detectors are not as prone to false alarms.
Answer:
D
Explanation:
196)
196)
How should the vacuum gauge and vacuum pump be connected to a four–port manifold?
A)
The vacuum gauge is connected to the evaporator coil, and the vacuum pump is connected
to the discharge service valve.
B)
The vacuum gauge is connected to the 3/8–in center port, and the vacuum pump is
connected to the 1/4–in center pump.
C)
The vacuum gauge is connected to the 1/4–in center port, and the vacuum pump is
connected to the 3/8–in center pump.
D)
The vacuum gauge is connected to the discharge service valve, and the vacuum pump is
connected to the evaporator coil.
Answer:
C
Explanation:
50
197)
197)
For a deep vacuum to complete, the system pressure should hold:
A)
Somewhere between 5,001 and 10,000 microns.
B)
Below 500 microns.
C)
Somewhere between 1,500 and 5,000 microns.
D)
Above 500 microns.
Answer:
B
Explanation:
198)
198)
Why is evacuating a refrigeration system important?
A)
Evacuation is the only procedure to ensure that noncondensable gases and moisture are
removed from HFC systems with a POE lubricant.
B)
Evacuation increases the system head pressure and compression ratio.
C)
Increases in the system high–side pressure and temperature can only be accomplished by
proper evacuation.
D)
Noncondensable gases and moisture, the two most common system contaminants, can be
removed through evacuation.
Answer:
D
Explanation:
199)
199)
The vacuum level on a system being evacuated pulls down to 2,000 microns, but goes no lower
even as the vacuum pump continues to run. This indicates:
A)
That the refrigeration oil is incompatible with the refrigerant in the system.
B)
That the vacuum is complete.
C)
The presence of water in the system.
D)
That the system is charged with the wrong type of refrigerant.
Answer:
C
Explanation:
51
200)
200)
When properly done, evacuation also ensures:
A)
An increase in the system compression ratio.
B)
An increase of refrigerant pressure.
C)
A leak–tight system.
D)
A reduction in the amount of condenser surface available.
Answer:
C
Explanation:
201)
201)
What effect do noncondensable gases have on a refrigeration system?
A)
They decrease the compression ratio and condenser pressure.
B)
They increase evaporator pressure and decrease compression ratio.
C)
They create bubbles in the liquid refrigerant stream leaving the compressor.
D)
They increase condenser pressure and compression ratio.
Answer:
D
Explanation:
202)
202)
The purpose of evacuating a refrigeration system is to:
A)
Remove moisture.
B)
Remove noncondensable gases and moisture.
C)
Remove noncondensable gases.
D)
Remove refrigerant oil.
Answer:
B
Explanation:
203)
203)
The compressor ina system operating with noncondensable gases:
A)
Runs hotter than normal.
B)
Makes a whistling noise when it shuts off.
C)
Runs cooler than normal.
D)
Has an unusually low amp draw.
Answer:
A
Explanation:
52
204)
204)
Acid is created within a refrigeration system when:
A)
Noncondensable gases collect within the condenser.
B)
Moisture is teamed with refrigerant in the refrigeration system.
C)
There are large quantities of air within a refrigeration system.
D)
The compression ratio within the system is significantly increased.
Answer:
B
Explanation:
205)
205)
Which of the following describes the consequence of noncondensable gases collecting in the
condenser and the resulting increases in refrigerant temperature and pressure?
A)
The corrosion of metals throughout the system
B)
An increase in the efficiency of the refrigeration system
C)
A reduction of system capacity and an increase in energy usage
D)
A freeze–up at the expansion valve or metering device
Answer:
C
Explanation:
206)
206)
Which of the following accurately describes the danger of air in the refrigeration system?
A)
The presence of air makes it impossible to connect a vacuum pump, which is necessary to
perform the evacuation procedure.
B)
Too much air makes it impossible to properly calibrate an analog vacuum gauge within the
refrigeration system.
C)
Oxygen will chemically react with the refrigeration oil and deposits buildup in the
discharge valve area, causing compressor motor burnouts.
D)
Oxygen may violently react with hydrogen and potentially cause a fire within the
refrigeration system.
Answer:
C
Explanation:
53
207)
207)
Assuming that atmospheric pressure is 29.92 in Hg, which of the following measures is a perfect
vacuum?
A)
20 in Hg vacuum
B)
29.92 in Hg vacuum
C)
0 in Hg vacuum
D)
9.92 in Hg vacuum
Answer:
B
Explanation:
208)
208)
Which of the following measures is a perfect vacuum if absolute measurement is used?
A)
9.92 in Hg absolute
B)
0 in Hg absolute
C)
29.92 in Hg absolute
D)
20 in Hg absolute
Answer:
B
Explanation:
209)
209)
What effect does moisture have on a refrigeration system?
A)
Increased low–side pressure
B)
Lower–than–normal superheat
C)
Corrosion of metals and freeze–up at the expansion valve
D)
Increased head pressure
Answer:
C
Explanation:
210)
210)
Vacuum pumps are rated by:
A)
Blank–off pressure.
B)
Inches of mercury vacuum.
C)
CFM capacity and blank–off pressure.
D)
CFM capacity.
Answer:
C
Explanation:
54
211)
211)
Evacuation will proceed faster:
A)
With Schrader valve cores removed.
B)
With Schrader valve cores in place using positive shutoff hoses.
C)
With hoses that have positive shutoff check valves.
D)
With Schrader valve cores in place.
Answer:
A
Explanation:
212)
212)
What is considered a good vacuum level for a deep vacuum?
A)
1,000 microns
B)
28 in Hg vacuum
C)
100 microns
D)
500 microns
Answer:
D
Explanation:
213)
213)
The best place to connect the vacuum gauge is:
A)
Vacuum gauge placement is not critical.
B)
On the manifold gauges.
C)
On the system.
D)
On the vacuum pump.
Answer:
C
Explanation:
214)
214)
How much refrigerant does the condensing unit of a new split–system air conditioning system
contain?
A)
None; they are shipped empty.
B)
Enough for the condensing unit, evaporator coil, and 15 to 30 ft of refrigerant line
C)
Just enough for the condensing unit
D)
Enough for the condensing unit and evaporator coil
Answer:
B
Explanation:
55
215)
215)
Two variables that have a great impact on the system performance of air–conditioning systems
are:
A)
Return–air wet–bulb temperature and the airflow across the evaporator.
B)
Airflow across the condenser and condenser water flow.
C)
High–side pressure and condenser water flow.
D)
High–side pressure and airflow across the condenser.
Answer:
A
Explanation:
216)
216)
More charge should be added to a system if:
A)
The system subcooling is more than 1°F higher than specified.
B)
The system subcooling is more than 1°F lower than specified.
C)
The system subcooling is exactly the same as specified.
D)
The system subcooling is less than 1°F higher than specified.
Answer:
B
Explanation:
217)
217)
A split system’s data plate is useful because:
A)
The detailed procedure for charging a new split system can be found on it.
B)
The factory charge is shown on the data plate.
C)
It always shows how much refrigerant to add or subtract.
D)
It provides instructions for proper evacuation of the refrigeration system.
Answer:
B
Explanation:
218)
218)
A fixed–restriction system operating with a refrigerant undercharge will have:
A)
Higher temperature drop across the evaporator.
B)
A low system superheat.
C)
A high system superheat.
D)
A high subcooling.
Answer:
C
Explanation:
56
219)
219)
The standard AHRI design condition used for rating unitary air–conditioning equipment is:
A)
80°F outdoor ambient temperature, 95°F dry–bulb, 67°F wet–bulb indoor temperature.
B)
95°F outdoor ambient temperature, 80°F dry–bulb, 67°F wet–bulb indoor temperature.
C)
90°F outdoor ambient temperature, 75°F dry–bulb, 67°F wet–bulb indoor temperature.
D)
80°F outdoor ambient temperature, 80°F dry–bulb, 67°F wet–bulb indoor temperature.
Answer:
B
Explanation:
220)
220)
What is the total system charge for a system with a factory charge of 56 oz of R–410A, an assumed
length of 15 ft, and a3/8 in liquid line that is 35 ft long?
A)
68 oz total system charge
B)
86 oz total system charge
C)
72 oz total system charge
D)
94 oz total system charge
Answer:
A
Explanation:
221)
221)
Which of the following conditions would likely increase the system high–side pressure?
A)
A restricted liquid–line filter drier
B)
Increase in the outdoor ambient temperature for air–cooled units
C)
An underfeeding metering device
D)
A dirty indoor air filter
Answer:
B
Explanation:
57
222)
222)
The most accurate method of charging a small appliance that holds less than a lb of refrigerant is
to add:
A)
Liquid into the system until the pressure equals the saturation pressure and temperature.
B)
Vapor with the system not operating up to a specified static pressure at a specified ambient
temperature.
C)
Vapor into the low side with the system operating while checking the compressor amp
draw.
D)
Liquid into the system with the system off until the liquid stops going in.
Answer:
B
Explanation:
223)
223)
A fixed–restriction system operating with a refrigerant overcharge will have:
A)
A low subcooling.
B)
Higher temperature drop across the evaporator.
C)
A high system superheat.
D)
A low system superheat.
Answer:
D
Explanation:
224)
224)
Using the liquid–line ambient temperature approach method to check the charge, if the liquid line
is cooler than specified:
A)
The amount of charge in the system does not affect the liquid–line temperature.
B)
The system is overcharged.
C)
The system is charged correctly.
D)
The system is undercharged.
Answer:
B
Explanation:
58
225)
225)
An air conditioner with a thermostatic expansion valve is operating with a condenser saturation
temperature of 110°F and a liquid–line temperature of 85°F. The factory–specified subcooling for
the current operating condition is 10°F. After checking the condenser coil and airflow, the
technician should:
A)
Recover charge because the system is overcharged.
B)
Move some of the charge from the low side of the system to the high side of the system to
balance the charge.
C)
Leave the charge alone because it is cooling even better than factory specifications.
D)
Add charge because the system is undercharged.
Answer:
A
Explanation:
226)
226)
What type of refrigerant must leave the cylinder as a liquid to prevent the separation of the
different components in refrigerant?
A)
Azeotropic mixtures
B)
Comlb
C)
Zeotropic mixtures
D)
All refrigerants
Answer:
C
Explanation:
227)
227)
Can zeotropes be metered in with the unit operating?
A)
Yes, by slightly cracking open the low–side manifold valve and then closing it
B)
Yes, only if the temperature exposure of the cylinder is above 125°F
C)
No, as the system must be turned off first
D)
No, if an early R–410A cylinder with a dip tube is being used
Answer:
A
Explanation:
59
228)
228)
A thermostatic expansion valve system operating with a refrigerant undercharge will have:
A)
A low superheat.
B)
A high system subcooling.
C)
A low system subcooling.
D)
Higher–than–normal compressor amp draw.
Answer:
C
Explanation:
229)
229)
An air conditioner is operating with low system pressures, an evaporator saturation temperature
of 20°F, and a suction line temperature of 24°F. The suction line is frosting. The most likely cause
of these symptoms is:
A)
Excessive humidity in the air, causing the coil to frost up.
B)
The system is overcharged.
C)
The system is undercharged.
D)
Reduced airflow across the evaporator.
Answer:
D
Explanation:
230)
230)
To reset a tripped circuit breaker, the technician should:
A)
Move the breaker switch to the on position.
B)
Reinstall the breaker in the electric panel.
C)
First turn the breaker off, and then back on.
D)
Use a wireless breaker tool to reboot the breaker.
Answer:
C
Explanation:
60