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231)
231)
Suction line filters are generally designed:
A)
To stay in the system permanently once installed.
B)
For biflow capability in heat pumps.
C)
To be interchangeable with liquid line driers.
D)
To be removed after the system is clean.
Answer:
D
Explanation:
A)
B)
C)
D)
232)
232)
Which of the following is an example of baseline evaporator data?
A)
Discharge pressure
B)
Discharge temperature
C)
Entering air wet bulb temperature
D)
Amp draw for the system
Answer:
C
Explanation:
A)
B)
C)
D)
233)
233)
You should flush the system:
A)
Until no more oil or debris comes out of the line.
B)
Until the solvent can is empty.
C)
For 5 to 10 minutes per foot of line.
D)
For 5 to 10 minutes per pound of charge.
Answer:
A
Explanation:
A)
B)
C)
D)
234)
234)
What breaks down to form poisonous gas in the presence of flames?
A)
A1 refrigerant only
B)
Compressor insulation
C)
Halogenated refrigerants
D)
Refrigerant oil
Answer:
C
Explanation:
A)
B)
C)
D)
61
235)
235)
How can you tell when a filter drier is stopped up?
A)
The "plugged filter" flag will pop out of the leaving flare port.
B)
It will have a pressure drop of more than 2 psi across the filter.
C)
You will hear a whistling sound in the filter.
D)
You will see the accumulated debris in the filter's sight glass.
Answer:
B
Explanation:
A)
B)
C)
D)
236)
236)
If the liquid oil acid test kit cannot be used, indicators may be used to connect to the:
A)
Oil drain plug.
B)
Gas exhaust.
C)
Suction line.
D)
Liquid refrigerant line.
Answer:
C
Explanation:
A)
B)
C)
D)
237)
237)
After flushing the lines and coils, the flush should be purged out:
A)
With nitrogen.
B)
With the same type of refrigerant the system uses.
C)
With compressed air.
D)
With mineral spirits.
Answer:
A
Explanation:
A)
B)
C)
D)
238)
238)
When debrazing a joint on a refrigeration system, often:
A)
The vacuum created by the flames will cause a quick inward suction when the tube is
pulled.
B)
The residual refrigerant will crystallize around the tube outlet.
C)
The exiting fumes will extinguish the torch flame.
D)
The oil fumes will ignite when the joint is opened.
Answer:
D
Explanation:
A)
B)
C)
D)
62
239)
239)
If a restriction clears up when the system is turned off and allowed to warm, the restriction was
probably due to:
A)
Acid.
B)
Noncondensables.
C)
Moisture.
D)
Carbon.
Answer:
C
Explanation:
A)
B)
C)
D)
240)
240)
The effects of moisture in the refrigeration system are which of the following? You may select
more than one.
A)
Acid formation in the system
B)
Internal system corrosion
C)
Higher-than-normal pressures
D)
Dilution of the refrigerant oil
E)
Metering device freeze-up
Answer:
A, E
Explanation:
A)
B)
C)
D)
E)
241)
241)
If you try to remove tubing before all the brazing material is molten, the tubing will:
A)
Not move.
B)
Warp or bend.
C)
Break off in the joint.
D)
Remove easily.
Answer:
C
Explanation:
A)
B)
C)
D)
63
242)
242)
Select the parameters that are included in a baseline performance check. You may select more
than one.
A)
Condenser fan RPM
B)
Discharge line temperature
C)
Compressor body temperature
D)
Compressor amp draw
E)
Discharge pressure
F)
Suction pressure
Answer:
B, E, F
Explanation:
A)
B)
C)
D)
E)
F)
243)
243)
What is meant by a system's baseline data?
A)
The minimum amount of current required to operate the system
B)
A record of all maintenance and service performed on the system
C)
The physical dimensions of a unit's lower platform
D)
A record of all the system performance specifications when the system is operating as
designed
Answer:
D
Explanation:
A)
B)
C)
D)
244)
244)
When cleaning up after a compressor burnout, immediately after you recover the refrigerant, you
should:
A)
Evacuate the system.
B)
Charge the system.
C)
Flush the system.
D)
Install filter driers.
Answer:
C
Explanation:
A)
B)
C)
D)
245)
245)
What kind of chart is required when calculating the liquid-line subcooling?
A)
Refrigerant pressure chart
B)
Atmospheric pressure chart
C)
Temperature difference chart
D)
Pressure-temperature chart
Answer:
D
Explanation:
A)
B)
C)
D)
64
246)
246)
If the safety reset on an oil furnace primary control is tripped:
A)
It will automatically reset on the next call for heat.
B)
The burner motor will not operate.
C)
Nothing on the furnace will operate.
D)
The ignition transformer will not operate.
Answer:
C
Explanation:
A)
B)
C)
D)
247)
247)
Technicians that use a systems approach to troubleshooting:
A)
Must understand the interrelationship between different system components.
B)
Only work on systems that they are already familiar with.
C)
Typically check the resistance of all the electrical components in the system.
D)
Replace the components that fail most often.
Answer:
A
Explanation:
A)
B)
C)
D)
248)
248)
If some components are not functioning, and the system has line and control voltage, you should
next:
A)
Replace the starter components.
B)
Replace the components.
C)
Determine if the components are receiving voltage.
D)
Repair the circuit to the components.
Answer:
C
Explanation:
A)
B)
C)
D)
249)
249)
Documenting all the work performed:
A)
Is required by law.
B)
Keeps the customer informed.
C)
Helps to generate the bill.
D)
Protects you legally.
Answer:
C
Explanation:
A)
B)
C)
D)
65
250)
250)
When is the best time to inform a customer regarding the cost of an expensive part that must be
changed?
A)
Before actually changing the part
B)
Over the phone after the call is completed
C)
In the mail when the bill is sent
D)
At the completion of the service call
Answer:
A
Explanation:
A)
B)
C)
D)
251)
251)
After replacing a blown fuse in a unit disconnect, the technician should:
A)
Swap some wires around to see if it helps.
B)
Check the system amp draw and compare it to the data plate rating.
C)
Check the frequency and phase angle of the voltage at the unit with the unit operating.
D)
Check the resistance of every system component.
Answer:
B
Explanation:
A)
B)
C)
D)
252)
252)
Why should service technicians be familiar with company pricing policies?
A)
The technician should always try to sell the service customer new equipment.
B)
Most customers are not concerned with the cost, leaving the technician entirely in charge of
repair costs.
C)
Technicians should always try to use parts and refrigerant that are on sale first.
D)
Cost is often the foremost question in the customer's mind.
Answer:
D
Explanation:
A)
B)
C)
D)
253)
253)
When trying to diagnose an open pressure switch, which manufacturer-supplied reference will
probably be the most helpful?
A)
The fault code reference list
B)
The symptoms list
C)
The benchmark data
D)
The logic flowchart
Answer:
A
Explanation:
A)
B)
C)
D)
66
254)
254)
A problem that can look like refrigerant overcharge if a service technician is only looking at
system pressures is:
A)
High evaporator airflow.
B)
An overfeeding refrigerant metering device.
C)
Low evaporator airflow.
D)
Low condenser airflow.
Answer:
D
Explanation:
A)
B)
C)
D)
255)
255)
A system that is overcharged will operate with:
A)
A low subcooling and a high superheat.
B)
A low subcooling and a low superheat.
C)
A high subcooling and a low superheat.
D)
A high subcooling and a high superheat.
Answer:
C
Explanation:
A)
B)
C)
D)
256)
256)
What part of the service call can often be completed before arriving on the job?
A)
Gathering typical replacement parts in the order they will be replaced
B)
Understanding the system operational sequence
C)
Making out the bill
D)
Compiling a list of the most frequently replaced parts that month
Answer:
B
Explanation:
A)
B)
C)
D)
257)
257)
Hopscotching is the technique that requires you to start at a point with correct voltage and then
move one lead at a time until:
A)
Line voltage doubles.
B)
Voltage is lost.
C)
You reach the nonfunctioning unit.
D)
The component begins functioning again.
Answer:
B
Explanation:
A)
B)
C)
D)
67
258)
258)
Larger-tonnage refrigerant units use which kinds of chillers?
A)
Centrifugal and screw compressor chillers
B)
Scroll and centrifugal compressor chillers
C)
Reciprocating and screw compressor chillers
D)
Reciprocating and scroll compressor chillers
Answer:
A
Explanation:
A)
B)
C)
D)
259)
259)
In order to leak test a low-pressure chiller, the chiller pressure:
A)
Must be recovered and replaced with nitrogen.
B)
Must be increased to a positive pressure less than 10 psig.
C)
Must be reduced to a safe level, under 150 psig.
D)
Should be increased by adding nitrogen.
Answer:
B
Explanation:
A)
B)
C)
D)
260)
260)
Oil is removed from the refrigerant vapor by a:
A)
Mist eliminator in the heater.
B)
Coil in the vaporizer.
C)
Valve in the cooler.
D)
Filter in the condenser.
Answer:
A
Explanation:
A)
B)
C)
D)
261)
261)
Smaller chillers typically use:
A)
Rotary or hermetic compressors.
B)
Reciprocating or scroll compressors.
C)
Centrifugal or rotary compressors.
D)
Centrifugal or screw compressors.
Answer:
B
Explanation:
A)
B)
C)
D)
68
262)
262)
Why does the lithium bromide and water solution go through a heat exchanger?
A)
To filter out the lithium bromide
B)
To recycle the solution
C)
To use the solution to heat the air
D)
To remove the water vapor
Answer:
D
Explanation:
A)
B)
C)
D)
263)
263)
Which type of compressor chiller uses a pair of rotors to compress the refrigerant gas?
A)
Centrifugal compressor chillers
B)
Reciprocating compressor chillers
C)
Screw compressor chillers
D)
Scroll compressor chillers
Answer:
C
Explanation:
A)
B)
C)
D)
264)
264)
How does the water vapor from the lithium bromide solution return to the evaporator?
A)
It condenses in the chiller.
B)
It condenses in the heat exchanger.
C)
It passes through the chiller.
D)
It passes through the condenser.
Answer:
D
Explanation:
A)
B)
C)
D)
265)
265)
The refrigerant in an absorption chiller is:
A)
HFC 134a.
B)
Lithium bromide.
C)
HCFC 123.
D)
Water.
Answer:
D
Explanation:
A)
B)
C)
D)
69
266)
266)
How does the refrigeration oil return from the chiller to the compressor?
A)
It is carried back by the refrigerant.
B)
The oil stays in the compressor, eliminating the need for returning it.
C)
Through an oil return system
D)
The oil return pump moves the oil from the chiller to the compressor.
Answer:
C
Explanation:
A)
B)
C)
D)
267)
267)
To avoid freezing the water in the chiller during recovery:
A)
Add nitrogen to the chiller.
B)
Turn off the condenser water pumps.
C)
Circulate the chiller water.
D)
Operate the chiller.
Answer:
C
Explanation:
A)
B)
C)
D)
268)
268)
What is the lowest water temperature required for effective radiant floor heating?
A)
90°F to 105°F
B)
75°F to 90°F
C)
105°F to 120°F
D)
60°F to 75°F
Answer:
A
Explanation:
A)
B)
C)
D)
269)
269)
Why do closed hydronic systems include pressure-relief valves, expansion tanks, and
temperature and pressure-limiting devices?
A)
Because freezing must be prevented and antifreeze may not be added
B)
Because building codes require certain controls on every system
C)
Because water expands and contracts as its temperature changes
D)
Because the copper piping used in the system requires these measures
Answer:
C
Explanation:
A)
B)
C)
D)
70
270)
270)
In a one-pipe venturi system:
A)
Only part of the water flows through each convector in the loop.
B)
All the water flows through each convector in the loop.
C)
Each convector is supplied with the same temperature hot water.
D)
The amount of water flowing through each individual convector is controlled by a
thermostat.
Answer:
A
Explanation:
A)
B)
C)
D)
271)
271)
Why should an air vent never be put on a closed-type expansion tank?
A)
The large amount of air in the expansion tank would overload the air vent.
B)
Closed-type expansion tanks are normally installed at a low point in the system.
C)
The expansion tank is usually not located in a serviceable location.
D)
A closed expansion tank requires an air head to work properly.
Answer:
D
Explanation:
A)
B)
C)
D)
272)
272)
What is used to top off the water supply for the system?
A)
A pressure-regulating valve
B)
The low-water cutout
C)
The return water line
D)
The supply pump
Answer:
A
Explanation:
A)
B)
C)
D)
273)
273)
Why are steam boilers used in applications requiring a large heating capacity?
A)
Because steam pumps operate more efficiently than hot water pumps
B)
Because a pound of steam takes up less space than a pound of water
C)
Because they provide heat beyond the range of a hot-water boiler
D)
Because hot water boilers cannot maintain a temperature over 212°F
Answer:
C
Explanation:
A)
B)
C)
D)
71
274)
274)
What is the purpose of cooling tower fill material?
A)
Slows the falling water and increases the surface exposure for evaporation
B)
Provides a growing surface for algae and plants that help clean the water
C)
Filters out dirt and debris from the cooling tower water
D)
Increases the rigidity of the cooling tower structure
Answer:
A
Explanation:
A)
B)
C)
D)
275)
275)
What does cooling tower pump head mean?
A)
The front of the water sump circulating pump
B)
The distance from the cooling tower and the system using the water
C)
The pressure required to lift the water from the water basin to the top of the tower and force
it through the distribution system spray nozzles
D)
The top of the water sump circulating pump
Answer:
C
Explanation:
A)
B)
C)
D)
276)
276)
What is the theoretical evaporation rate?
A)
5 percent of the water supplied for every 15°F of cooling
B)
0.5 percent of the water supplied for every 1°F of cooling
C)
5 percent of the water supplied for every 10°F of cooling
D)
1 percent of the water supplied for every 10°F of cooling
Answer:
D
Explanation:
A)
B)
C)
D)
277)
277)
Each pound of water evaporated by the cooling tower removes how much latent heat?
A)
970 BTU
B)
900 BTU
C)
950 BTU
D)
1,000 BTU
Answer:
A
Explanation:
A)
B)
C)
D)
72
278)
278)
The heat load for a cooling tower is equal to the pounds of water circulated multiplied by:
A)
The latent heat factor for vaporizing water.
B)
The wet-bulb depression.
C)
The approach.
D)
The cooling range.
Answer:
D
Explanation:
A)
B)
C)
D)
279)
279)
The visible cloud that exits a cooling tower during cool, damp weather is called a cooling tower:
A)
Plume.
B)
Drift.
C)
Tail.
D)
Carryover.
Answer:
A
Explanation:
A)
B)
C)
D)
280)
280)
How does a cooling tower remove energy from the water it is circulating?
A)
It cools the water flowing through it by using a separate compression refrigeration system.
B)
It cools the water flowing through it by passing it over ice that is made during off-peak
hours.
C)
It cools the refrigerant by evaporating a small portion of the refrigerant to the air.
D)
It cools the water flowing through it by evaporating a small portion of the water.
Answer:
D
Explanation:
A)
B)
C)
D)
281)
281)
When antifreeze is added to water, its specific heat:
A)
Decreases, decreasing the cooling ability of the water.
B)
Increases, increasing the cooling ability of the water.
C)
Increases, decreasing the cooling ability of the water.
D)
Decreases, increasing the cooling ability of the water.
Answer:
A
Explanation:
A)
B)
C)
D)
73
282)
282)
Which of the following statements regarding the mechanical-draft cooling tower is correct?
A)
There is only one design for a mechanical-draft cooling tower–the hyperbolic design.
B)
The primary means of drawing air though the mechanical-draft cooling tower is the density
difference between the air inside and outside the tower.
C)
Mechanical-draft cooling towers are used only for small-scale installation requiring a few
gallons of water per minute.
D)
The mechanical-draft cooling tower uses a fan to move air through the tower.
Answer:
D
Explanation:
A)
B)
C)
D)
283)
283)
Induced-draft, forced-draft, counterflow, and crossflow cooling towers are all examples of:
A)
An atmospheric-draft cooling tower.
B)
A natural-flow cooling tower.
C)
A mechanical-draft cooling tower.
D)
A hyperbolic cooling tower.
Answer:
C
Explanation:
A)
B)
C)
D)
284)
284)
What is the purpose of a cooling tower?
A)
To reduce the temperature of cooling water by evaporation
B)
To produce cool air by evaporation
C)
To add humidity to the outdoor air when it is too dry
D)
To evaporate the excess water created in an industrial process
Answer:
A
Explanation:
A)
B)
C)
D)
285)
285)
A hot-gas defrost cycle will progress in the same manner as the:
A)
Secondary defrost system.
B)
Electric defrost system.
C)
Secondary-loop system.
D)
Natural defrost system.
Answer:
B
Explanation:
A)
B)
C)
D)
74
286)
286)
How can improperly loading an open display case adversely affect its operation?
A)
It can block the condenser airflow.
B)
It can disrupt the air curtain.
C)
It can add more heat load on one shelf than another.
D)
It can interfere with the operation of the case modulation damper.
Answer:
B
Explanation:
A)
B)
C)
D)
287)
287)
How does air from air-conditioning vents affect open display cases?
A)
It improves their performance by lowering the temperature of the air surrounding the
display case.
B)
Open display cases are not affected by external air sources because of their powerful
built-in air curtains.
C)
It disrupts the case's air curtain, causing them to rise in temperature.
D)
Open display cases are not affected by external air sources because of their engineered air
baffles.
Answer:
C
Explanation:
A)
B)
C)
D)
288)
288)
A traditional compression refrigeration cycle that condenses the refrigerant in the condenser is a:
A)
Subcritical system.
B)
Transcritical system.
C)
Supercritical system.
D)
Noncritical system.
Answer:
A
Explanation:
A)
B)
C)
D)
289)
289)
How is the water level in the reservoir of an ice machine maintained at the correct level?
A)
The reservoir has an overflow so water can safely spill over the edge.
B)
The water control measures incoming water pressure.
C)
The reservoir is filled and sealed at the factory.
D)
A float switch
Answer:
D
Explanation:
A)
B)
C)
D)
75
290)
290)
The amount of ice required for a restaurant is approximately:
A)
30 lb per person.
B)
6 lb per person.
C)
3 lb per person.
D)
5 lb per person.
Answer:
C
Explanation:
A)
B)
C)
D)
291)
291)
How does a cuber typically make the ice cubes?
A)
Water fills a horizontal tray that is kept below freezing.
B)
Water is frozen in a cube-shaped mold one cube at a time.
C)
Water fills a cylinder and freezes on the inner walls.
D)
Water is circulated through freezing cells .
Answer:
D
Explanation:
A)
B)
C)
D)
292)
292)
Most flake ice machines utilize this type of evaporator.
A)
A vertical, rectangular, stainless steel evaporator
B)
A vertical, cylindrical, tube-shaped stainless steel evaporator
C)
A horizontal, rectangular, stainless steel evaporator
D)
A horizontal, cylindrical, tube-shaped stainless steel evaporator
Answer:
B
Explanation:
A)
B)
C)
D)
293)
293)
Which ice is often added to drinks and is easy to chew?
A)
Cubed ice
B)
Shaved ice
C)
Crushed ice
D)
Flake ice
Answer:
C
Explanation:
A)
B)
C)
D)
76
294)
294)
Select the characteristics of cubed ice. You may select more than one.
A)
95 percent hardness
B)
Faster melting
C)
Clear
D)
Cloudy
E)
70 percent hardness
F)
Slower melting
Answer:
A, C, F
Explanation:
A)
B)
C)
D)
E)
F)
295)
295)
What is the possible cause for ice sticking and not releasing during the harvest cycle?
A)
An inlet water valve leaking
B)
A hot-gas valve stuck closed
C)
A blocked distribution tube
D)
A dirty evaporator
Answer:
D
Explanation:
A)
B)
C)
D)
296)
296)
One common method of determining when the ice bin is full is:
A)
A strain gauge on the bottom of the bin.
B)
When the ice bin is full, there is no room for water in the reservoir, so the ice machine shuts
down.
C)
When the ice bin is full, the evaporator gets too warm and will no longer chill to make ice.
D)
An ice level probe.
Answer:
D
Explanation:
A)
B)
C)
D)
297)
297)
The harvest cycle on an ice machine:
A)
Releases the ice cubes after they are made.
B)
Keeps the machine clean by harvesting biological growth off the sides of the machine.
C)
Fills the water sump.
D)
Begins the freezing process.
Answer:
A
Explanation:
A)
B)
C)
D)
77
298)
298)
How do evaporators in medium-temperature refrigeration cases normally defrost?
A)
Hot gas is bypassed around the condenser straight into the evaporator.
B)
Small defrost gas burners
C)
The case air circulates over the coil while the compressor is off.
D)
Electric heaters built into the evaporator coil
Answer:
C
Explanation:
A)
B)
C)
D)
299)
299)
A suction superheat measurement higher than the manufacturer's recommended superheat
setting indicates that:
A)
The system is operating even better than the manufacturer's design.
B)
The system is operating correctly.
C)
Too much refrigerant is being fed into the evaporator.
D)
Too little refrigerant is being fed into the evaporator.
Answer:
D
Explanation:
A)
B)
C)
D)
300)
300)
How is a compressor's rated load amp rating, RLA, determined?
A)
It is the maximum current that the compressor should draw.
B)
It is the average of the operating current across all operating conditions for which the
system is designed.
C)
It is the compressor's maximum continuous current rating divided by 1.56.
D)
It is the current draw at the compressor's capacity rating point.
Answer:
C
Explanation:
A)
B)
C)
D)
301)
301)
To check for electrical potential at a switch or a load, technicians use a(n):
A)
Ohmmeter.
B)
Ammeter.
C)
Voltmeter.
D)
Potentiometer.
Answer:
C
Explanation:
A)
B)
C)
D)
78
302)
302)
Electrical components can generally be divided into two groups:
A)
Electrical and mechanical.
B)
Electro-mechanical and electronic.
C)
Pilot duty and line duty.
D)
Controls and loads.
Answer:
D
Explanation:
A)
B)
C)
D)
303)
303)
Overdefrosting is caused by:
A)
A compressor failure.
B)
A condenser fan failure.
C)
A defrost initiation failure.
D)
A defrost termination failure.
Answer:
D
Explanation:
A)
B)
C)
D)
304)
304)
What effect do noncondensable gases have on system performance?
A)
They cause a decrease in head pressure and an increase in capacity.
B)
They cause an increase in head pressure and a decrease in capacity.
C)
They cause a decrease in both head pressure and capacity.
D)
Noncondensables do not affect condenser pressure because they do not condense.
Answer:
B
Explanation:
A)
B)
C)
D)
305)
305)
To increase the operating superheat on a thermostatic expansion valve:
A)
The power head should be tightened one-quarter turn on the valve.
B)
The adjusting stem should be turned counterclockwise.
C)
The adjusting stem should be turned clockwise.
D)
The sensing bulb should be moved farther away from the evaporator.
Answer:
C
Explanation:
A)
B)
C)
D)
79
306)
306)
The three major electrical defects in compressor motors that can be identified using an ohmmeter
are:
A)
Open, shorted, or grounded.
B)
Phased, unbalanced, or blown.
C)
Single-phasing, dual-phasing, and three-phasing.
D)
Locked, under capacity, and unbalanced.
Answer:
A
Explanation:
A)
B)
C)
D)
307)
307)
When installing a split-system small commercial refrigeration system, the condensing unit
normally contains:
A)
Enough refrigerant for both the condensing unit and the evaporator, but not the refrigerant
lines.
B)
Enough refrigerant for the entire system, including a set length of lines.
C)
Enough refrigerant for just the condensing unit alone.
D)
No refrigerant, just a nitrogen holding charge.
Answer:
D
Explanation:
A)
B)
C)
D)
308)
308)
HVACR equipment placement may be affected by local ordinances governing:
A)
Traffic.
B)
Vibration.
C)
Noise.
D)
Costs.
Answer:
C
Explanation:
A)
B)
C)
D)
309)
309)
What is the position of the unit installation valves on split-system air-conditioning condensers
when the unit is shipped?
A)
Front seated
B)
The valves are shipped with the cores removed.
C)
Backseated
D)
Mid position
Answer:
A
Explanation:
A)
B)
C)
D)
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