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WorksheetsACR-105 Baseline Assessment
Total questions: 160
Worksheet time: 2hrs 7mins
Name
Class
Date
1.
The automatic control of a system is intended to ____.
a)
maintain stable or constant conditions without excessive human interference
b)
maintain the working conditions of the equipment with a controllable device
c)
evaluate overloading situations
d)
maintain safe operations for service technicians
2.
Modulating controls are used to ____.
a)
vary the speed of a motor
b)
start motors
c)
stop motors
d)
stop the flow of a liquid
3.
When a control is required to control space or product temperature, it is called a ____.
a)
thermostat
b)
safety device
c)
pressure control
d)
speed control
4.
A thermal system overload may occur if a specific electrical or mechanical component is not cooled properly, resulting in ____.
a)
overheating
b)
underload
c)
failure
d)
stagnation pressure
5.
Devices, such as thermostats, that open and close their contacts during the ____ operation of the system are referred to as operational controls.
a)
normal
b)
initial
c)
final
d)
most recent
6.
The compressor in the refrigerator has a protective device that keeps it from overloading and damaging itself. This device is called a(n) ____.
a)
overload
b)
capacitor
c)
mass control
d)
speed control
7.
The metals most often used in a bimetal temperature control are ____.
a)
brass and steel
b)
copper and brass
c)
copper and steel
d)
brass and aluminum
8.
An example of a bimetal device is a ____.
a)
snap-disc
b)
mercury-filled tube and diaphragm
c)
thermistor
d)
Bourdon tube
9.
The Bourdon tube ____.
a)
straightens out with an increase in vapor pressure
b)
straightens out with an increase in voltage
c)
curls inward with an increase in vapor pressure
d)
straightens out with an increase in electrical current
10.
A thermocouple is a device that ____.
a)
converts heat to electrical energy
b)
converts heat to mechanical movement
c)
converts heat to fluid flow
d)
couples two temperature controls together
11.
Brass and steel have a different rate of expansion and contraction when heated or cooled.
a)
True
b)
False
12.
Fluid expansion is a way to sense temperature change.
a)
True
b)
False
13.
Bellows are normally used with a vapor instead of a liquid inside it.
a)
True
b)
False
14.
A properly operating thermocouple connected to a solenoid in a gas valve should put out 20 to 30 millivolts.
a)
True
b)
False
15.
A thermistor is a device that produces a voltage across the hot and cold junctions when heated.
a)
False
b)
True
16.
The most common device used to sense change in temperature is called a(n) ____________________.
a)
Bimetal strip
b)
Metal strip
c)
Tube
d)
Rod
17.
Adding length to a bimetal element is done by shaping the element. The shapes used are coiled, helix, hairpin, and ____________________.
a)
Worm
b)
Strip
c)
Tube
d)
Rod
18.
The most popular type of bimetal element used for temperature control of a gas hot water heater is rod and ____________________.
a)
Tube
b)
Strip
c)
Duct
d)
Rod
19.
A common application for the rod and tube type of control is in a(n) ____________________-mounted limit control.
a)
Duct
b)
Strip
c)
Wall
d)
Ceiling
20.
A bellows is much like a(n) ____________________ ̶ it has a lot of internal volume and a lot of travel.
a)
Accordion
b)
Bevel
c)
Saxophone
d)
Drums
21.
When referring to thermocouples, the hot ____________________ is at a higher temperature level than the cold ____________________.
a)
Junction
b)
Bevel
c)
Strip
d)
Tube
22.
Define "bimetal strip."
a)
A bimetal strip has two different metals connected back to back. These metals expand and contract at different rates when heated or cooled
b)
A bimetal strip has two of the same metals connected back to back. These metals expand and contract at different rates when heated or cooled
c)
A bimetal strip has two different metals connected front to front. These metals expand and contract at different rates when heated or cooled
d)
A bimetal strip has two different metals connected back to back. These metals do not expand and contract at different rates when heated or cooled
23.
Why are two different metals used to produce movement in bimetal elements?
a)
The metals expand and contract at different rates as temperature changes.
b)
The metals expand and contract at the same rates as temperature changes.
c)
The metals expand and contract at different rates as volume changes.
d)
The metals expand and contract at different rates as temperature stays the same.
24.
To make a bimetal element operate over a wide temperature range, what is done to the element?
a)
The strip is lengthened.
b)
The strip is shortened.
c)
The tube is lengthened.
d)
Nothing.
25.
True of False: Define a diaphragm used in controls
The diaphragm is a thin, flexible, movable membrane (brass, steel, or other metal) used to convert pressure changes to movement. This movement can stop, start, or modulate controls.
a)
True
b)
False
26.
What is the major advantage of a remote bulb control?
a)
The control body can be located outside the controlled area for better access.
b)
The control body can be located inside the controlled area for better access.
c)
The control plunger can be located outside the controlled area for no access.
d)
The control body can be located outside the insulated area for rough access.
27.
Explain the difference between a Positive Temperature Coefficient (PTC) thermistor and a Negative Temperature Coefficient (NTC) thermistor.
a)
The resistance of a PTC increases as the temperature increases. The resistance of a NTC decreases as the temperature increases.
b)
The resistance of a PTC decreases as the temperature increases. The resistance of a NTC increases as the temperature increases.
c)
The resistance of a PTC increases as the temperature decreases. The resistance of a NTC decreases as the temperature increases.
d)
The resistance of a PTC increases as the temperature increases. The resistance of a NTC decreases as the temperature decreases.
28.
What is a thermopile?
a)
A thermopile is a group of thermocouples wired in series with each other to provide a higher output voltage
b)
A thermopile is a single thermocouple wired in series with each other to provide a higher output voltage
c)
A thermopile is a group of thermocouples wired in parallel with each other to provide a higher output voltage
d)
A thermopile is a group of thermocouples wired in series with each other to provide a lower output voltage
29.
Thin metal membrane that can operate controls based on the pressure exerted on it
a)
Diaphragm
b)
Bimetal strip
c)
thermocouple
d)
thermopile
30.
Based on the concept that different metals will react differently to heat causing current to flow
a)
Thermocouple
b)
Bimetal strip
c)
Thermistor
d)
Thermopile
31.
Bimetal device used to sense water heater temperatures
a)
Rod and Tube
b)
Bimetal strip
c)
Thermistor
d)
Thermopile
32.
A higher output thermocouple
a)
Thermopile
b)
Bimetal strip
c)
Thermistor
d)
Thermocouple
33.
Device whose resistance changes with respect to temperature; used to control electronic circuits
a)
Thermistor
b)
Bimetal strip
c)
Thermopile
d)
Thermocouple
34.
Two unlike metals connected back to back
a)
Bimetal strip
b)
Thermister
c)
Thermopile
d)
Thermocouple
35.
The purpose of a heat anticipator is to ____.
a)
reduce the temperature swing of a conditioned space
b)
anticipate a sudden rise in temperature
c)
keep the thermostat warm
d)
ensure that the system transformer does not overheat
36.
The difference between system overshoot and system lag is called ____.
a)
temperature swing
b)
room temperature
c)
temperature rise
d)
room swing
37.
The heater in the thermostat control circuit in the cooling mode is active when the ____.
a)
cooling contact is open
b)
cooling contact is closed
c)
fan switch is open
d)
fan switch is closed
38.
The heater in the thermostat control circuit in the heating mode is active when the ____.
a)
cooling contact is closed
b)
cooling contact is open
c)
fan switch is open
d)
fan switch is closed
39.
What is meant by the term "detent"?
a)
Rapid making and breaking of a contact.
b)
Slow motion of a contact to ensure good electrical contact.
c)
The compensation furnished by heaters in the thermostat.
d)
The control of the blower in the air handler.
40.
The cold anticipator is wired in ____ with the mercury bulb cooling contacts and is energized during the off cycle.
a)
parallel
b)
series
c)
sequence
d)
opposition
41.
To properly set the heat anticipator, the ____ must determine what the current flow is through the heating control circuit when the furnace is operating in a steady state condition.
a)
heating technician
b)
manufacturer
c)
homeowner
d)
electrician
42.
Line voltage thermostats have heavier contacts and use which type of sensing element?
a)
All of the above
b)
Bimetal
c)
Bellows
d)
Remote bulb
43.
To obtain an accurate reading of a fluid in a large pipe, a technician should ____.
a)
use a permanently mounted thermometer in a well
b)
strap a dial-type pocket thermometer to the pipe
c)
use a digital thermometer in a glass of ice water
d)
Any of the above will work fine.
44.
A low pressure control has a "high event" and a "differential" setting. The technician wants the system to turn on at 28 psig and shut down at 2 psig. What would be the proper settings?
a)
High event: 28 psig, differential: 26 psig.
b)
High event: 28 psig, differential: 2 psig.
c)
High event: 2 psig, differential: 2 psig.
d)
High event: 2 psig, differential: 28 psig.
45.
If the suction pressure of a system is 60 psig and the oil pump outlet is 85 psig, what is the net oil pressure?
a)
25 psig
b)
60 psig
c)
85 psig
d)
145 psig
46.
Oil pressure safety controls measure the difference in pressure to establish ____.
a)
that positive oil pressure is present
b)
that negative oil pressure is present
c)
the oil pump is running
d)
the compressor is running
47.
To prove that the combustion blower motor is operating before ignition, a ____ would be used.
a)
sail switch
b)
pressure differential switch
c)
toggle switch
d)
push button switch
48.
To control ice build-up on a heat pump outdoor coil in the heating cycle, a ____ is attached to a large diaphragm.
a)
micro-switch
b)
sail switch
c)
toggle switch
d)
push button switch
49.
Where would a water regulating valve that is controlling head pressure be installed?
a)
Water circuit at inlet of condenser.
b)
Discharge line at outlet of compressor.
c)
Suction line.
d)
Liquid line close to the condenser.
50.
When a water regulating valve is used to control the head pressure of a water-cooled system, the valve's spring is acting against which pressure to modulate the water flow?
a)
Head pressure of the system.
b)
Water pressure.
c)
Suction pressure.
d)
Atmospheric pressure.
51.
The heat anticipator in a thermostat prevents the temperature in the conditioned space from rising above the thermostat setting.
a)
True
b)
False
52.
The cold anticipator starts the cooling system early to allow the air-conditioning system to get up to capacity when needed.
a)
True
b)
False
53.
The advantage of using a thermistor-type thermometer over a mercury-filled thermometer for measuring refrigerant line temperature is that the thermistor-type does not have to be insulated.
a)
False
b)
True
54.
A helix coil is used in some applications to sense temperature in a moving air stream.
a)
True
b)
False
55.
A dual pressure control is actually a low pressure control and a high pressure control connected in parallel with each other.
a)
False
b)
True
56.
Many natural gas fired heating units operate at a manifold pressure of 3.5 in. WC.
a)
True
b)
False
57.
The term used to describe when the temperature of a heated room falls below the thermostat's set point is called ____________________.
a)
System lag
b)
Low temperature
c)
System low
d)
Low heat
58.
The term used to describe when the temperature of a heated room rises above the thermostat's set point is
a)
System overshoot
b)
High temperature
c)
System high
d)
High heat
59.
The heater that functions in a thermostat in the heating mode is called the ____________________.
a)
Heat anticipator
b)
Heater
c)
Heat control
d)
Heat temperature
60.
The heater that functions in a thermostat in the cooling mode is called the ____________________.
a)
Cold anticipator
b)
Heater
c)
Cold control
d)
Cold temperature
61.
High pressure control contacts are normally ____________________ type.
a)
Closed
b)
Open
c)
Stuck
d)
Switch
62.
List four reasons why low voltage controls are usually found on residential air conditioning systems?
a)
They are economical, safer, more accurate, and need no special license to install.
b)
They are economical, safer, less accurate, and need no special license to install.
c)
They are economical, safer, more accurate, and need a special license to install.
d)
They are not economical, safer, more accurate, and need no special license to install.
63.
Explain the most accurate way to measure the current through the heat anticipator.
a)
Is with an AC ammeter measuring current between the R and W terminals of the thermostat’s subbase.
b)
Is with an AC ammeter measuring current between the R and C terminals of the thermostat’s subbase.
c)
Is with an AC ammeter measuring current between the R and G terminals of the thermostat’s subbase.
d)
Is with an AC ammeter measuring current between the R and O terminals of the thermostat’s subbase.
64.
Where is the thermistor motor overload device usually positioned?
a)
It is embedded in the motor windings.
b)
It is outside the motor windings.
c)
It is next to the motor windings.
d)
It is outside the motor.
65.
Why is the thermistor type sensor normally embedded in the motor windings.
a)
The close contact with the windings gives fast, accurate response.
b)
The open contact with the windings gives fast, accurate response.
c)
The close contact with the windings gives slow, inaccurate response.
d)
The open contact with the windings gives slow, inaccurate response.
66.
What type of control would be used to cycle compressors on and off in response to evaporator pressures that indirectly control box temperatures?
a)
A low-pressure control would be used.
b)
A high-pressure control would be used.
c)
A voltage control would be used.
d)
An amphere control would be used.
67.
An oil pressure safety control usually has a 90-second time delay built into it.
a)
True
b)
False
68.
What device may be used to ensure that air is flowing through a duct before an electric strip heater is energized?
a)
Sail switch
b)
Volume switch
c)
Pressure switch
d)
Voltage switch
69.
A control can be which of the following?
a)
all of the above
b)
electrical
c)
mechanical
d)
electrical and mechanical
70.
An example of a power consuming device would be a(n) ____ while an example of a non-power consuming device would be a(n) ____.
a)
light bulb, single-pole single-throw switch
b)
light bulb, electric motor
c)
single-pole single-throw switch, light bulb
d)
electric motor, light bulb
71.
An electrical power consuming component ____.
a)
is also known as a load
b)
is often a basic switch
c)
is normally used to pass power to another component
d)
is normally wired in series in an electrical circuit
72.
The line side of a switch is the ____.
a)
side the power source is connected to
b)
side the load is connected to
c)
neutral side of the circuit
d)
side with the white wire
73.
If an air conditioning system is calling for cooling and the compressor is running but the indoor (evaporator) fan is not running, which terminal on the thermostat will the technician most likely check first?
a)
G
b)
R
c)
Y
d)
W
74.
The _____ is nothing more than a set of switches.
a)
Thermostat
b)
Transformer
c)
Coil
d)
Motor
75.
The continuity through a heat relay is checked using a(n) ____.
a)
ohmmeter
b)
voltmeter
c)
clamp-on ammeter
d)
micron gauge
76.
A 10-wrap amperage multiplier is used with a(n) ____.
a)
clamp-on ammeter
b)
voltmeter
c)
ohmmeter
d)
megger
77.
Transformers are rated using ____.
a)
volt-amperes
b)
volt-ohms
c)
amperes-ohms
d)
volt-resistance
78.
A(n) ____ is the easiest diagram to use to follow a circuit. This diagram normally can be studied briefly, and the circuit function should become obvious.
a)
ladder diagram
b)
pictorial diagram
c)
layout
d)
oblique drawing
79.
An electrical diagram showing the approximate location of the components is called a(n) ____.
a)
pictorial diagram
b)
ladder diagram
c)
layout
d)
oblique drawing
80.
If line one of a circuit had a potential of 120 V and line two was neutral, the potential voltage (difference) between line one and line two would be zero volts.
a)
True
b)
False
81.
The heat anticipator in a thermostat is usually an adjustable type.
a)
True
b)
False
82.
The cooling anticipator in a thermostat is usually an adjustable type.
a)
False
b)
True
83.
When checking thermostat circuits, an insulated jumper wire is a handy tool.
a)
True
b)
False
84.
When conditions are correct, the rheostat will pass power through the device onto the system components to be controlled.
a)
False
b)
True
85.
A 120-V/24-V control transformer has a VA rating of 20. The maximum amperage the transformer will put out is 0.8 amps.
a)
True
b)
False
86.
When using a ten-wrap multiplier, the reading on the meter must be multiplied by ten.
a)
False
b)
True
87.
Electrical controls are divided into two categories: power-consuming and _________________________.
a)
power passing
b)
power pressing
c)
voltage passing
d)
voltage pressing
88.
Non-power-consuming, or power-passing, devices are commonly referred to as ____________________.
a)
Switches
b)
Controls
c)
Converters
d)
Power
89.
While checking a simple series 115-V circuit containing a fuse, a switch, and a light bulb, the technician's voltmeter reads 115 volts across the light bulb socket. The light bulb is not on. Tech correctly concludes that the ____________________ is defective.
a)
Bulb
b)
Circuit
c)
Fuse
d)
Switch
90.
One way to troubleshoot a(n) ____________________ on a heating and cooling system is to first turn the fan selector switch to the FAN ON position and see if the fan starts.
a)
Thermostat
b)
Thermistor
c)
A/C
d)
Switch
91.
Without _________________________ voltage, there is no low voltage.
a)
High
b)
Slow
c)
Multi
d)
Variable
92.
The thermostat, pressure control, and cooling contactor coil are found in series with the "Y" terminal of a low voltage control circuit.
a)
True
b)
False
93.
How is the cooling anticipator normally wired to the cooling contacts?
a)
It is wired in parallel.
b)
It is wired in series.
c)
Not wired.
d)
Does not apply.
94.
How is the heat anticipator normally wired to the heating contacts?
a)
It is wired in series.
b)
It is wired in parallel.
c)
Not wired.
d)
Does not apply.
95.
In a residential air conditioning system, how are the outdoor fan and compressor wired with respect to each other?
a)
It is wired in parallel.
b)
It is wired in series.
c)
Not wired.
d)
Does not apply.
96.
T/F What are the three components that have to operate when a residential air conditioning system is in the cooling mode?
The indoor fan, the compressor, and the outdoor fan.
a)
True
b)
False
97.
In a high voltage circuit, is the fan motor a power-passing or power-consuming device?
a)
Power Consuming
b)
Power Passing
c)
Both
d)
Neither
98.
When applying a voltmeter to measure the voltage of a power source, on what range is the meter set?
a)
Higher than supply voltage or the top range of the meter
b)
Lower than supply voltage or the top range of the meter
c)
Higher than supply voltage or the lowest range of the meter
d)
Lower than supply voltage or the lowest range of the meter
99.
What is the amperage capacity of a 240-V/24-V control transformer with a 40 VA rating?
a)
1.66 amps
b)
1.7 amps
c)
.6 amps
d)
2 amps
100.
A ____ reacts to stop, start, or modulate the flow of water, air, or refrigerant to the system or conditioned space
a)
controlled device
b)
sensor
c)
controller
d)
none of the above
101.
All control systems can be subdivided into ____, no matter how many controls there are.
a)
control loops
b)
throttle loops
c)
control segments
d)
sensor segments
102.
____ control systems were used before electronics.
a)
Pneumatic
b)
Manual
c)
Digital
d)
Mechanical
103.
Pneumatic controls must have a permanent air supply that is ____.
a)
clean and dry
b)
warm and dry
c)
clean and moist
d)
clean and warm
104.
Most system compressors provide ____ psig of air pressure to the storage tank.
a)
100 to 125
b)
90 to 100
c)
90 to 125
d)
100 to 150
105.
In most system compressors, the compressors are controlled with a ____.
a)
pressure switch
b)
heat switch
c)
limiter
d)
governor
106.
A ____ is either in the pressure reducer or in the downstream side of the system to ensure that the control air pressure does not exceed about 30 psig.
a)
relief valve
b)
blowback valve
c)
pulldown valve
d)
pressure valve
107.
In a(n) ____ loop, all changes happen within the loop.
a)
closed
b)
open
c)
modified-closed
d)
modified-open
108.
A device called a ____ is used to control the large volume of air in an air conditioning system.
a)
pilot positioner
b)
pilot lockout
c)
pilot fixator
d)
pilot engagement
109.
The pilot positioner has a main air supply that is governed by the ____.
a)
internal diaphragm
b)
internal switch
c)
internal lockout
d)
internal float
110.
Controlling the water flow to the room’s needs is called ____.
a)
modulating flow
b)
regulating flow
c)
operating flow
d)
systemic flow
111.
The temperature in the room is known as the ____ air temperature.
a)
ambient
b)
associated
c)
causal
d)
variable
112.
Electronic controls are commonly called ____.
a)
direct digital controls
b)
discrete digital controls
c)
direct analog controls
d)
discrete event controls
113.
The controlled environment could be controlled by an array of ____ such as dampers, fans, variable-frequency drives.
a)
controlled output devices
b)
direct digital controls
c)
controlled input devices
d)
operational devices
114.
____, usually housed internally inside the controller, convert the information from either analog to digital (A/D) or digital to analog (D/A) format.
a)
Signal converters
b)
Transceivers
c)
Signal processors
d)
Signal managers
115.
The very first control systems were used to start and stop the various components.
a)
True
b)
False
116.
Space temperature is the only temperature that is important in modern systems.
a)
False
b)
True
117.
Modern control systems only have on-off control capability.
a)
False
b)
True
118.
Today control output devices can receive signals as either analog or digital.
a)
True
b)
False
119.
DDC is a control process in which a microprocessor, acting as a digital controller, constantly updates a database of internal information.
a)
True
b)
False
120.
Controllers are devices that can measure some type of environmental parameter or a controlled variable and convert this parameter to a value that the controller can understand.
a)
False
b)
True
121.
The ____________________ is the device that responds to a change in conditions.
a)
Sensor
b)
Controller
c)
Microprocessor
d)
Memory
122.
In a home air-conditioning system, the ____________________ is the sensor.
a)
Thermostat
b)
Controller
c)
Microprocessor
d)
A/C
123.
____________________ driers use some of the same products that refrigerant driers use, silica gel or molecular sieve as an adsorbent.
a)
Desiccant
b)
Gel
c)
Foam
d)
Dryer
124.
The _______________ system actually changes or conditions a signal in three steps.
a)
DDC
b)
DAC
c)
DEC
d)
OTC
125.
________________ is the part of the digital controller where this information is stored.
a)
Memory
b)
Storage
c)
Sensor
d)
Converter
126.
_______________ are devices that can measure some type of environmental parameter or a controlled variable and converting this parameter to a value that the controller can understand.
a)
Sensors
b)
Storages
c)
Microprocessors
d)
Converters
127.
_______________________ send information back to the controller in terms of resistance (ohms).
a)
Passive sensors
b)
Active sensors
c)
Microprocessors
d)
Multi-converters
128.
__________________________ send information back to the controller in terms of milliamps (mA) or volts.
a)
Active sensors
b)
Passive sensors
c)
Microprocessors
d)
Multi-converters
129.
Thermostat has some small switches in the back that are called ____________________ switches that allow the technician to set this thermostat up for the particular piece of equipment that it is controlling
a)
DIP
b)
LIP
c)
MIP
d)
SIP
130.
As a rule of thumb, the air leaving the evaporator will be about ___ than the air entering the evaporator.
a)
10-15° warmer
b)
10-15° cooler
c)
17-20° cooler
d)
17-20° warmer
131.
A service valve can be used to ___.
a)
check the electrical service to the compressor
b)
isolate the refrigerant so the system can be serviced
c)
check the air flow across the evaporator
d)
check the ambient temperature at the condenser
132.
A typical evaporator superheat reading at the evaporator outlet for a central air-conditioning system on a 95°F day would be ___°F.
a)
5-7
b)
8-10
c)
10-12
d)
12-15
133.
On a 95°F day, the R-22 refrigerant pressure on the high side should be about ___ psig.
a)
108
b)
182
c)
243
d)
297
134.
The liquid line temperature is used to determine the ___ of a condenser.
a)
superheat
b)
lowside pressure
c)
suction pressure
d)
subcooling
135.
To accurately add refrigerant to a system, a condenser ambient temperature of ___°F should be simulated.
a)
75
b)
85
c)
95
d)
100
136.
The instrument to use to check for a short in the compressor motor winding is a(n) ___.
a)
ohmmeter
b)
ammeter
c)
voltmeter
d)
milliammeter
137.
With a rise in outdoor temperature, the head pressure will rise.
a)
True
b)
False
138.
Superheat occurs in the condenser as well as the evaporator.
a)
True
b)
False
139.
The best way to tell if a compressor's discharge line is at the correct temperature is to grab hold of it.
a)
True
b)
False
140.
Subcooling occurs in the evaporator as well as the condenser.
a)
True
b)
False
141.
When checking the electrical circuits of an air-conditioning system, each parallel circuit should be isolated and checked separately.
a)
True
b)
False
142.
If a compressor has a partially shorted winding, it could run for a while, overheat, and shut off.
a)
True
b)
False
143.
Reducing the CFM through the evaporator will cause the head pressure to (a) .
144.
On most gauge manifolds, the suction or low side gauge is located on the (a) .
145.
Temperature difference is used to describe the difference in the inlet and (a) temperature of a heat exchanger.
146.
Two types of fixed-bore metering devices are capillary tubes and (a) .
147.
Reducing the CFM through the evaporator will cause the amperage draw of the compressor to (a) .
148.
Why do we measure temperatures at the evaporator rather than the suction pressure?
(a)
149.
Why should a technician visually inspect the equipment before installing gauges?
4 lines
150.
When is it necessary to connect gauges onto a system?
a)
only when temperature tests show a refrigerant quantity or flow problem.
b)
only when temperature tests do not show a refrigerant quantity or flow problem.
c)
both
d)
none of the above
151.
While passing through the condenser, refrigerant is in three different states. What are they?
a)
superheated vapor, saturated, subcooled liquid
b)
superheated vapor, saturated, subcooled vapor
c)
superheated liquid, saturated, subcooled liquid
d)
superheated liquid, saturated, subcooled vapor
152.
Where is the correct location for a sight glass in order to check the charge?
(a)
153.
What is the process that normally begins the electrical troubleshooting of the system?
a)
verifying that the power supply is energized and that the voltage is correct.
b)
verifying that the power supply is energized and that the voltage is incorrect.
c)
verifying that the power supply is deenergized and that the voltage is correct.
d)
none of the above
154.
Refrigerant Overcharge
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
155.
Refrigerant Undercharge
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
156.
blocked/dirty filter
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
157.
non-condensable gas in system
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
158.
defective condenser fan motor
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
159.
defective evaporator fan motor
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
160.
dirty condenser coil
a)
high operating pressures
b)
low operating pressures
c)
frozen evaporator coil
d)
low superheat
e)
high superheat
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