157)
157)
The normal fluid temperature drop through a glycol coil on a secondary cooling loop is:
A)
20°F.
B)
15°F.
C)
5°F.
D)
10°F.
Answer:
D
Explanation:
A)
B)
C)
D)
158)
158)
An electric defrost cycle is accomplished by:
A)
Leaving the case fans operating and shutting off the compressor.
B)
Through normal use from customers opening and closing the doors.
C)
Shutting off the compressor and bypassing hot gas to the evaporator.
D)
Shutting off the compressor and energizing electric defrost heaters.
Answer:
D
Explanation:
A)
B)
C)
D)
159)
159)
A strange high–pitched squeal coming from a flake ice machine with a low production of soft,
mushy ice is an indication of:
A)
A bad compressor.
B)
A dirty evaporator.
C)
A bad auger motor bearing.
D)
A failing water recirculation pump.
Answer:
B
Explanation:
A)
B)
C)
D)
160)
160)
Select the characteristics of a flake ice maker. You may select more than one.
A)
Large rectangular evaporator
B)
Cylindrical evaporator
C)
Uses a slow–turning auger to crack off the ice
D)
Alternating ice making and harvest cycles
E)
Continuous ice making and delivery
F)
Uses hot gas bypass to release ice from the evaporator
Answer:
B, C, E
Explanation:
A)
B)
C)
D)
E)
F)
41
161)
161)
What is the purpose of a photo–electric eye on an ice machine?
A)
The photo–electric eye detects when the ice bin is empty.
B)
The photo–electric eye detects when no ice production has occurred and speeds up the
freezing and harvesting cycles.
C)
The photo–electric eye detects when the ice bin is full.
D)
The photo–electric eye detects when no ice production has occurred and shuts down the
unit, even if the bin is not full.
Answer:
D
Explanation:
A)
B)
C)
D)
162)
162)
Ice machine cleaning and sanitizing:
A)
Are normally done by pouring chlorine bleach into the water sump.
B)
Are necessary only in areas with hard water.
C)
Are normally both performed using a single cleaning and sanitizing solution.
D)
Are separate processes required for two different solutions.
Answer:
D
Explanation:
A)
B)
C)
D)
163)
163)
Circulating water over the evaporator while the ice is freezing:
A)
Keeps air bubbles and solids from freezing in the ice.
B)
Eliminates the need for a reservoir float.
C)
Increases the air bubbles in the ice.
D)
Adds interesting swirled effects in the ice patterns.
Answer:
A
Explanation:
A)
B)
C)
D)
164)
164)
Ice machine capacity is normally stated as:
A)
Pounds of ice per hour.
B)
Pounds of ice per day.
C)
Pounds of ice per week.
D)
Pounds of ice per minute.
Answer:
B
Explanation:
A)
B)
C)
D)
42
165)
165)
What are some differences between a flake ice machine and a cube ice machine?
A)
The flake ice machine has a vertical cylindrical evaporator and makes ice continuously,
while the cube ice machine has a horizontal rectangular evaporator and makes ice in cycles.
B)
The flake ice machine has the same safety devices as the cube ice machine, as no additional
safety devices are needed.
C)
The flake ice machine does not have a bin control or a photo–electric eye like a cube ice
machine.
D)
The flake ice machine has a horizontal rectangular evaporator and makes ice in cycles,
while the cube ice machine has a vertical cylindrical evaporator and makes ice
continuously.
Answer:
A
Explanation:
A)
B)
C)
D)
166)
166)
The amount of ice required for a salad bar is approximately
A)
30 lb per cubic foot.
B)
6 lb per cubic foot.
C)
3 lb per cubic foot.
D)
5 lb per cubic foot.
Answer:
A
Explanation:
A)
B)
C)
D)
167)
167)
How is the ice removed from the vertical evaporator plate after it reaches the proper thickness?
A)
The compressor continues to operate and a reversing valve switches the evaporator and
condenser.
B)
The compressor continues to operate and a hot gas solenoid sends hot discharge gas to the
evaporator.
C)
The compressor turns off and the mold heater is energized.
D)
The compressor turns off and the sweeper pushes the cubes out.
Answer:
B
Explanation:
A)
B)
C)
D)
43
168)
168)
Select the characteristics of a cube ice machine. You may select more than one.
A)
Uses a slow–turning auger to crack off the ice
B)
Cylindrical evaporator
C)
Alternating ice making and harvest cycles
D)
Continuous ice making and delivery
E)
Uses hot gas bypass to release ice from the evaporator
F)
Large rectangular evaporator
Answer:
C, E, F
Explanation:
A)
B)
C)
D)
E)
F)
169)
169)
What can cause odors or slime build–up in an ice machine?
A)
Odor and slime build–up are caused by poor–quality water coming into the system.
B)
Odor and slime build–up are caused by bacteria and fungi growth.
C)
Too many minerals in the water cause odor and slime build–up in an ice machine.
D)
Cleaning the ice machine too often can cause odor and slime build–up.
Answer:
B
Explanation:
A)
B)
C)
D)
170)
170)
Select the safety controls found on a flake ice machine that are not typically found on a cube
machine. You may select more than one.
A)
High–pressure switch
B)
Auger rotation sensor
C)
Auger motor overcurrent sensor
D)
Ice thickness sensor
E)
Low water safety cutout
Answer:
B, C, E
Explanation:
A)
B)
C)
D)
E)
44
171)
171)
Poor ice quality and low production are common problems for ice makers. What could be a
possible cause of small cubes and lack of production?
A)
Low inlet water flow only
B)
High discharge pressure or a blocked metering device only
C)
Low inlet water flow or refrigerant undercharge only
D)
Low inlet water flow, refrigerant undercharge, high discharge pressure, or a blocked
metering device
Answer:
D
Explanation:
A)
B)
C)
D)
172)
172)
How is ice quality measured?
A)
Ice quality is measured in the amount of minerals per inch.
B)
Ice quality is measured by the purity of the ice.
C)
Ice quality is measured by the size of the individual ice pieces.
D)
Ice quality is measured in percentage of hardness.
Answer:
D
Explanation:
A)
B)
C)
D)
173)
173)
Ice that has the appearance of snow is called:
A)
Block ice.
B)
Cubed ice.
C)
Shaved ice.
D)
Flake ice.
Answer:
C
Explanation:
A)
B)
C)
D)
174)
174)
What could cause corrosion of a stainless steel ice–maker?
A)
Acidic water or too much chlorine gas in the water supply
B)
Water with too much alkaline content
C)
Unfiltered water with too much air in the supply line
D)
Water with a pH above 7 or not enough chlorine gas in the water supply
Answer:
A
Explanation:
A)
B)
C)
D)
45
175)
175)
What are six applications for a commercial ice machine?
A)
Home refrigerators, grocery stores, restaurants, cafeterias, hotels, and hospitals
B)
Restaurants, cafeterias, home refrigerators, hotels, hospitals, and cruise ships
C)
Hotels, hospitals, cruise ships, theme parks, home refrigerators, and soda machines
D)
Restaurants, cafeterias, hotels, hospitals, cruise ships, and theme parks
Answer:
D
Explanation:
A)
B)
C)
D)
176)
176)
How is the ice removed from the evaporator of a flake ice machine?
A)
The evaporator is teflon coated so the ice slides right off.
B)
A harvest cycle using hot gas bypass
C)
A slow–turning spiral–fluted auger cracks the ice off.
D)
The flexible mold is twisted until the ice releases.
Answer:
C
Explanation:
A)
B)
C)
D)
177)
177)
To prevent mineral buildup and scale on an ice machine:
A)
Use a water filter to remove suspended solids.
B)
Clean regularly with a chlorine disinfectant.
C)
Use an ultraviolet light.
D)
Test the pH of the incoming water.
Answer:
A
Explanation:
A)
B)
C)
D)
178)
178)
What is the difference between crushed ice and flake ice?
A)
Flake ice is made as a cube and shaved into flakes.
B)
They are two names for the same product.
C)
Crushed ice is made as a cube and mechanically crushed.
D)
Flake ice is made by spraying water into an evacuated chamber.
Answer:
C
Explanation:
A)
B)
C)
D)
46
179)
179)
One basic rule a technician must follow while searching for a leak is to:
A)
Work quickly before the leak disappears.
B)
Start by injecting a sealing compound into the system.
C)
Have patience.
D)
Use one leak method and move on.
Answer:
C
Explanation:
A)
B)
C)
D)
180)
180)
Select possible cause(s) of an iced–up evaporator on a commercial freezer. You may select more
than one.
A)
Bad condenser fan motor
B)
Open defrost heaters
C)
Dirty condenser
D)
Bad defrost timer motor
E)
Shorted defrost termination switch
F)
Bad evaporator fan motor
Answer:
B, D, E, F
Explanation:
A)
B)
C)
D)
E)
F)
181)
181)
With three–phase compressors, a voltage imbalance of greater than ________ will cause the
windings within a motor to generate heat beyond safe levels, leading to premature motor failure.
A)
1 percent
B)
2 percent
C)
3 percent
D)
4 percent
Answer:
B
Explanation:
A)
B)
C)
D)
47
182)
182)
With the compressor off, a technician compares the pressure of an air–cooled condenser with the
pressure given on the PT chart for that refrigerant and temperature. The system pressure is
considerably higher than the pressure indicated on the PT chart for that refrigerant and
temperature. This indicates that:
A)
The system has been slightly overcharged.
B)
The system has been properly evacuated and charged.
C)
The system has noncondensable gases in it.
D)
The system has been undercharged.
Answer:
C
Explanation:
A)
B)
C)
D)
183)
183)
Voltage drop across a switch indicates that:
A)
The switch is closed.
B)
The switch is operating.
C)
The switch is open.
D)
The wire to the switch is sized incorrectly.
Answer:
C
Explanation:
A)
B)
C)
D)
184)
184)
To check the amount of electrical current a load is drawing, technicians use a(n):
A)
Potentiometer.
B)
Ammeter.
C)
Voltmeter.
D)
Ohmmeter.
Answer:
B
Explanation:
A)
B)
C)
D)
185)
185)
When troubleshooting single–phase compressor motors, it is important that the technician:
A)
Check the frequency of the power source.
B)
Check the start relay, start capacitor, and run capacitor.
C)
Check for phase reversal between L1 and L2.
D)
Measure the phase displacement between the two power legs.
Answer:
B
Explanation:
A)
B)
C)
D)
48
186)
186)
The capacitor testing function on many multimeters will not read correctly if:
A)
The capacitor is a dual capacitor.
B)
The capacitor has a bleed resistor.
C)
The capacitor is a start capacitor.
D)
The capacitor is a run capacitor.
Answer:
B
Explanation:
A)
B)
C)
D)
187)
187)
The coil of a current relay used with small single–phase compressors should have a resistance of
approximately:
A)
10,000 .
B)
250 .
C)
50 .
D)
0.1 .
Answer:
D
Explanation:
A)
B)
C)
D)
188)
188)
A suction superheat measurement lower 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:
C
Explanation:
A)
B)
C)
D)
189)
189)
When checking the resistance of the compressor start winding, the technician‘s multimeter shows
OL. This indicates that:
A)
The winding is grounded.
B)
The winding is open.
C)
The winding is shorted.
D)
The winding has continuity and is good.
Answer:
B
Explanation:
A)
B)
C)
D)
49
190)
190)
Select the possible causes of an overfeeding TEV. You may select more than one.
A)
Dead thermostatic bulb charge
B)
High superheat adjustment
C)
TEV sensing bulb not making good thermal contact
D)
Restricted filter drier
E)
Oversized TEV
F)
Low superheat adjustment
G)
Restricted inlet screen on TEV
H)
Undersized valve
Answer:
C, E, F
Explanation:
A)
B)
C)
D)
E)
F)
G)
H)
191)
191)
The run winding on a compressor has a resistance of 0 . This indicates that:
A)
The winding is open.
B)
The winding is shorted.
C)
The winding is grounded.
D)
The winding has continuity and is good.
Answer:
B
Explanation:
A)
B)
C)
D)
192)
192)
After diagnosing a defective compressor, the technician should:
A)
Determine why the original compressor failed.
B)
Add a hard start kit to improve compressor performance.
C)
Add refrigerant to improve compressor performance.
D)
Rebuild the compressor in the field.
Answer:
A
Explanation:
A)
B)
C)
D)
50
193)
193)
The contacts of a current starting relay are:
A)
Either normally open or normally closed depending upon the compressor.
B)
Normally open.
C)
Normally closed.
D)
Modulating.
Answer:
B
Explanation:
A)
B)
C)
D)
194)
194)
The correct way to discharge a capacitor is:
A)
To short across the terminals with a screwdriver.
B)
To connect 240 V AC to the terminals.
C)
To touch both ends of a 20 k, 5 W resistor across the terminals.
D)
To touch both ends of an 18 gauge wire across the terminals.
Answer:
C
Explanation:
A)
B)
C)
D)
195)
195)
On a starting relay, the component can be tested to see if it is electrically acceptable using a
standard ________ or capacitance meter.
A)
multimeter
B)
ohmmeter
C)
ammeter
D)
voltmeter
Answer:
A
Explanation:
A)
B)
C)
D)
196)
196)
When checking the resistance of the compressor start winding, the technician‘s multimeter shows
3.1 . This indicates that:
A)
The winding has continuity and is good.
B)
The winding is open.
C)
The winding is grounded.
D)
The winding is shorted.
Answer:
A
Explanation:
A)
B)
C)
D)
51
197)
197)
The contacts in a potential relay are:
A)
Normally open.
B)
Normally closed.
C)
Either normally open or normally closed depending on the compressor.
D)
Modulating type contacts.
Answer:
B
Explanation:
A)
B)
C)
D)
198)
198)
Of the four phases listed, which one is performed before the others?
A)
Piping installation
B)
Electrical connection
C)
Start and check
D)
Evacuation and charging
Answer:
A
Explanation:
A)
B)
C)
D)
199)
199)
To avoid turning the hermetic compressor shell into an exploding bomb, keep the system pressure
below:
A)
150 psig.
B)
250 psig.
C)
300 psig.
D)
200 psig.
Answer:
A
Explanation:
A)
B)
C)
D)
200)
200)
Test gases that may be safely used to test for leaks include:
A)
Oxygen.
B)
Compressed air.
C)
Acetylene.
D)
Nitrogen.
Answer:
D
Explanation:
A)
B)
C)
D)
52
201)
201)
When the unit is operating, the refrigerant cylinder pressure will be:
A)
Less than the back pressure of the evaporator.
B)
Less than the head pressure of the condenser.
C)
More than the back pressure of the condenser.
D)
More than the head pressure of the evaporator.
Answer:
B
Explanation:
A)
B)
C)
D)
202)
202)
Why are time–delay fuses or HVACR–rated circuit breakers used?
A)
They are cheaper than standard fuses and circuit breakers.
B)
They are used to prevent nuisance tripping when the compressor starts.
C)
They are easier to install than standard fuses and circuit breakers.
D)
They are required to meet current electrical codes.
Answer:
B
Explanation:
A)
B)
C)
D)
203)
203)
What phase comes just before start and check?
A)
Evacuation and charging
B)
Electrical connection
C)
Piping installation
D)
Equipment selection
Answer:
A
Explanation:
A)
B)
C)
D)
204)
204)
The National Electric Code and the National Fuel Gas Code are written by:
A)
Canadian Standards Association – CSA.
B)
The International Code Council – ICC.
C)
The Underwriters Laboratories – UL.
D)
The National Fire Protection Association – NFPA.
Answer:
D
Explanation:
A)
B)
C)
D)
53
205)
205)
A standards and testing organization that specializes in product safety is:
A)
The Underwriters Laboratories – UL.
B)
The Environmental Protection Agency – EPA.
C)
The International Code Council – ICC.
D)
The National Fire Protection Association – NFPA.
Answer:
A
Explanation:
A)
B)
C)
D)
206)
206)
Industry associations that establish national standards for the HVACR industry include:
A)
AC Standards Association and the Heating Standards Symposium.
B)
ARI, ASHRAE, and UL.
C)
EPA, OSHA, and DOE.
D)
DOT, MSHA, and CE.
Answer:
B
Explanation:
A)
B)
C)
D)
207)
207)
The National Electric Code, NEC, is enforced:
A)
Anywhere the OSHA has jurisdiction because it is an OSHA regulation.
B)
All across the nation because it is a federal law.
C)
In the District of Columbia because it is a federal regulation.
D)
In states and municipalities that have adopted the NEC.
Answer:
D
Explanation:
A)
B)
C)
D)
208)
208)
When adding zeotropes, you can throttle the refrigerant using the hand valves on the gauges or
add it as a:
A)
Gas to the output side of the compressor.
B)
Gas to the suction side of the compressor.
C)
Liquid directly to the compressor.
D)
Gas using a charging device in line with the cylinder.
Answer:
D
Explanation:
A)
B)
C)
D)
54
209)
209)
What happens if standard fuses and circuit breakers are used in the overload protection?
A)
Nuisance trips will occur when the compressor stops.
B)
Nuisance trips will occur when the compressor starts.
C)
The overload protection will not meet code.
D)
The overload protection will function normally.
Answer:
B
Explanation:
A)
B)
C)
D)
210)
210)
The disconnect for a piece of air–conditioning equipment should be equal to:
A)
115 percent of the maximum overcurrent rating listed on the equipment data plate.
B)
115 percent of the minimum circuit ampacity listed on the equipment data plate.
C)
The sum of the compressor RLA and the FLA of all fan motors.
D)
The minimum circuit ampacity listed on the equipment data plate.
Answer:
B
Explanation:
A)
B)
C)
D)
211)
211)
Which installation phase is performed first?
A)
Piping installation
B)
Electrical connection
C)
Ductwork installation
D)
Equipment placement
Answer:
D
Explanation:
A)
B)
C)
D)
212)
212)
The fuse protection for a piece of air–conditioning equipment should be sized using:
A)
The locked rotor current of all the equipment motors added together.
B)
The sum of the compressor RLA and the FLA of all fan motors.
C)
The minimum circuit ampacity listed on the equipment data plate.
D)
The maximum overcurrent rating listed on the equipment data plate.
Answer:
D
Explanation:
A)
B)
C)
D)
55
213)
213)
Which organization has written comprehensive and coordinated building safety and fire
prevention codes for residential, commercial, and educational buildings?
A)
Association of Plumbing Officials
B)
International Code Council
C)
Canadian Standards Association
D)
Underwriters Laboratory
Answer:
B
Explanation:
A)
B)
C)
D)
214)
214)
The power wire for a piece of air–conditioning equipment should be sized using:
A)
The locked rotor current of all the equipment motors added together.
B)
The sum of the compressor RLA and the FLA of all fan motors.
C)
The minimum circuit ampacity listed on the equipment data plate.
D)
The maximum overcurrent rating listed on the equipment data plate.
Answer:
C
Explanation:
A)
B)
C)
D)
215)
215)
For hydronic heating systems, routine maintenance covers the pump and controls, piping,
radiators and convectors, and the:
A)
Boiler.
B)
Furnace.
C)
Heating coil.
D)
Fan.
Answer:
A
Explanation:
A)
B)
C)
D)
216)
216)
As an operational safety check, the equipment rooms for combustion appliances should be
checked for high:
A)
Oxygen levels.
B)
Carbon monoxide levels.
C)
Nitrogen levels.
D)
Carbon dioxide levels.
Answer:
B
Explanation:
A)
B)
C)
D)
56
217)
217)
What can cause the supply voltage to an electric heating system to drop below the minimum
voltage when the unit is operated?
A)
The system may be low on refrigerant, causing a high amp draw as the compressor
struggles to cool the structure.
B)
Power wire is too small or there are poor connections at either end of the power wire.
C)
A dirty air filter may be causing a high evaporator fan motor amp draw.
D)
This is normal. The minimum voltage only refers to the voltage with the unit off.
Answer:
B
Explanation:
A)
B)
C)
D)
218)
218)
How does performing planned maintenance save the customer money?
A)
The customer will receive money–saving coupons to purchase new equipment.
B)
Reduced operational cost and longer equipment life
C)
The customer can apply for the federal air conditioning maintenance tax credit.
D)
Most air–conditioning contractors perform seasonal maintenance at no or reduced cost as a
public service.
Answer:
B
Explanation:
A)
B)
C)
D)
219)
219)
Define predictive maintenance.
A)
Monitoring key performance indicators and performing maintenance when these indicators
show a need for maintenance
B)
Performing maintenance and testing whenever the system quits operating correctly
C)
Performing maintenance and testing based on a regular schedule
D)
Replacing all system components on a rotating basis
Answer:
A
Explanation:
A)
B)
C)
D)
57
220)
220)
Before starting the unit:
A)
Purge the system with nitrogen.
B)
Remove the refrigerant.
C)
Check the power supply with the unit off.
D)
Check the low– and high–side pressures.
Answer:
C
Explanation:
A)
B)
C)
D)
221)
221)
What color should the flames be in a correctly adjusted gas burner?
A)
Bright blue inner cone with yellow tips
B)
Light blue in the inner cone with a dark blue outer cone
C)
Bright white inner cone with dark purple outer cone
D)
Dark orange inner flames with yellow tips
Answer:
B
Explanation:
A)
B)
C)
D)
222)
222)
To avoid system breakdown due to the failure of components that have a predictable service life,
it is wise to:
A)
Schedule parts replacements for wear items near the end of their service life.
B)
Install another backup system that can be quickly brought online.
C)
Always use pulleys that have two belts.
D)
Not purchase any equipment that has parts that can wear out.
Answer:
A
Explanation:
A)
B)
C)
D)
58
223)
223)
The cells on most electronic air cleaners can be cleaned:
A)
By spraying them in place with an air–conditioning coil cleaner.
B)
By spraying them in place using a solvent that is certified to be high in volatile organic
compounds.
C)
In the dishwasher.
D)
With a fine–grit emery cloth.
Answer:
C
Explanation:
A)
B)
C)
D)
224)
224)
The phases of a planned maintenance service call are:
A)
Routine maintenance and operational checks.
B)
Routine maintenance, troubleshooting, and replacing parts that cause problems on many
systems.
C)
Routine maintenance, prestart inspection, operational checks, and troubleshooting.
D)
Operational checks and troubleshooting.
Answer:
C
Explanation:
A)
B)
C)
D)
225)
225)
How often should the water–handling components of an ice machine be cleaned?
A)
Weekly
B)
Annually
C)
Monthly
D)
The water–handling components of an ice machine do not need cleaning.
Answer:
C
Explanation:
A)
B)
C)
D)
226)
226)
When performing an operation check, be sure to consult the:
A)
Data plate.
B)
Current voltage draw.
C)
Minimum voltage rating.
D)
Manufacturer’s specifications.
Answer:
D
Explanation:
A)
B)
C)
D)
59
227)
227)
How does scheduling maintenance save time and money?
A)
It allows you to safely run the system outside specifications.
B)
It prevents small problems from becoming big ones.
C)
It reduces time spent on routine maintenance.
D)
It prevents all system emergencies.
Answer:
B
Explanation:
A)
B)
C)
D)
228)
228)
What is the purpose of checking the supply voltage before operating the system?
A)
To figure out where to connect the power wiring to the unit
B)
To determine which power leg is positive and which is negative
C)
To determine the voltage drop in the wire
D)
To verify that the supplied voltage is within manufacturer’s specifications
Answer:
D
Explanation:
A)
B)
C)
D)
229)
229)
The voltage drop in the power wire is checked by:
A)
Reading the voltage before the unit starts and comparing it to the nameplate voltage.
B)
Comparing the minimum and maximum allowable operating voltages on the unit data
plate.
C)
Comparing the supplied voltage with the unit off to the voltage with the unit operating.
D)
Reading the voltage after the unit starts and comparing it to the nameplate voltage.
Answer:
C
Explanation:
A)
B)
C)
D)
230)
230)
During a planned maintenance call, technicians should check the power wiring to make sure:
A)
A heavy wire runs from both L1 and L2 to the equipment ground.
B)
The unit is not grounded.
C)
The unit is grounded.
D)
Any resilient mounted motors are isolated from ground.
Answer:
C
Explanation:
A)
B)
C)
D)
60