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WorksheetsHVAC FC 03
Total questions: 70
Worksheet time: 35mins
Name
Class
Date
1.
Compressors of oil control systems must be kept lubricated, but the oil must be prevented from moving through the system. What is not an oil control device?
a)
regulator device
b)
sight glass
c)
separator
d)
reservoir
2.
The approximate heat content of natural gas is
a)
950 to 1,150 Btu/ft3.
b)
1,225 to 1.650 Btu/ft3.
c)
2,500 to 3,200 Btu/ft3.
d)
3,500 to 3,800 Btu/ft3.
3.
For downflow units, condensate disposal water level monitoring devices MUST be installed inside the
a)
primary drain pan
b)
auxillary drain pan
c)
primary drain line
d)
auxillary drain line
4.
During installation or service of electrical controls, a digital multimeter set to voltage must be connected in what manner?
a)
in series
b)
in parallel
c)
in line with the source
d)
between the source and the load
5.
What will be the ton rating of a refrigerating mechanism capable of absorbing 1,440.000 Btus in 24 hours?
a)
4 tons
b)
5 tons
c)
6 tons
d)
8 tons
6.
Which of the following refrigerants will have the MOST static loss of pressure across a liquid line with a 30-foot vertical line?
a)
R-22
b)
R-134a
c)
R-404A
d)
R-507
7.
The absorption systems is different from the compression system in that uses
a)
heat energy
b)
mechanical energy
c)
high pressure vapor
d)
vapor compression
8.
From the list of personal protective equipment, which one is NOT included in such category?
a)
a hard hat
b)
a tool belt
c)
goggles
d)
steel toe boots
9.
Which component compresses refrigerant vapor?
a)
expansion valve
b)
evaporator
c)
compressor
d)
condenser
10.
A running capacitor in a system is being replaced. By how much greater can the capacitance be increased?
a)
5 percent
b)
10 percent
c)
15 percent
d)
20 percent
11.
When using the Dinh Heat Pipe Principle for very humid climates, moisture removal can be increased by
a)
0.1
b)
0.2
c)
0.3
d)
0.6
12.
What is the effect on the evaporator when the superheat of a system raises?
a)
flood.
b)
charge.
c)
heat.
d)
starve.
13.
Which factor does NOT affect the performance of a cooling tower?
a)
Water quality
b)
Refrigerant type
c)
Design conditions
d)
Humidity requirements
14.
In a single compressor of a multiple evaporator system a ___ allows fluid (refrigerant) in only one direction in the system.
a)
check valve
b)
unloader
c)
receiver
d)
accumulator
15.
According to OSHA, fall prevention systems for vertical lifelines safe points of anchorage are:
a)
something heavy on the ground such as a truck.
b)
structural members of buildings.
c)
standpipes or other mounted piping systems.
d)
pipe hangers.
16.
A worker has finished installing a gas piping system with 1,500 cubic feet of pipe volume. At least for how long he should test this system?
a)
24 hours
b)
12 hours
c)
1 1/2 hours
d)
1 hour
17.
Combustion air openings shall be covered with a corrosion-resistant screen having what size minimum opening?
a)
1/8 inch
b)
1/4 inch
c)
1/2 inch
d)
1 inch
18.
Work which is exempt from mechanical permit requirements ___.
a)
shall be insprcted
b)
is required to comply with the mechanical code
c)
shall be performed in compliance with an applicable national standard
d)
shall be performed in accordance with generally accepted local practices
19.
To evaporate liquid refrigerant trapped in the oil in the crankcase, which circuit should be activated first?
a)
low pressure circuit
b)
high pressure circuit
c)
low ambient circuit
d)
crankcase heater circuit
20.
A worker is using a portable extension ladder to go in and out of an excavation. The ladder side rails must be at LEAST ___ feet extending above the landing surface.
a)
3 1/2 feet
b)
4 feet
c)
2 1/2 feet
d)
3 feet
21.
During calculating energy loads, the ETD measures ___.
a)
air infiltration.
b)
mixed air temperature.
c)
the effect of the sun.
d)
heat loss through masonry walls.
22.
The typical water vapor saturation curve for air shows the effect of temperature and the amount of moisture that air will hold. If the air temperature raises from 55 to 75 degrees F, what will happen to the amount of moisture in the air?
a)
almost double.
b)
decrease about 20%.
c)
remain about the same.
d)
increase about 20%
23.
Which of the following will NOT cause high head pressure?
a)
dirty condenser
b)
overcharged of refrigerant
c)
oversized metering device
d)
noncondensables in the system
24.
OSHA mandates that trench protection or sloping of a ditch to be AT LEAST ____ feet deep.
a)
5 feet
b)
7 feet
c)
3 feet
d)
4 feet
25.
Avoid contact with contaminated lubricant from a hermetic system that is dirty and smells bad because it may be
a)
acidic
b)
explosive
c)
phosgenic
d)
radioactive
26.
In most commercial system installations, sight glasses are usually installed in the liquid lines. A few bubbles may be seen when the systems first starts, however, bubbles during normal run time operation could be a result of ___.
a)
restrictions in the circuit
b)
contaminates in the system
c)
clogged filter
d)
suction line leak
27.
What maintains the head pressure on commercial condensers during low ambient temperature conditions?
a)
Fan controller
b)
Oil reservoir
c)
Pressure switch
d)
Check valve and limiter value
28.
When we mention that this instrument is used to measure the relative humidity of the air by comparing wet and dry bulb temperature, we are talking about ____.
a)
a rheostat
b)
a sail switch
c)
an ohmmeter
d)
a sling psychrometer
29.
The ___ is the appropriate piping material that can be embedded in a concrete floor for a hydronic heating system.
a)
cast iron
b)
polybutylene rating
c)
copper tubing
d)
PVC
30.
In low temperature units such as food freezers and frozen food units, the refrigerant oil should have
a)
high hydro-carbons
b)
high wax content
c)
extra low pour points
d)
a low viscosity rating
31.
A hot water boiler adjustment is important to avoid injury or scalding. A typical setting for the boiler water would be between the temperature range of
a)
200 - 220 degrees F
b)
180 - 200 degrees F
c)
160 - 180 degrees F
d)
140 - 160 degrees F
32.
An absorption system consists of a condenser, receiver and evaporator similar to those in a compression system. In this case however, the compressor is replaced by ___.
a)
a heater and generator
b)
a direct drive compressor
c)
an evaporative cooler
d)
a restricting system
33.
Which of the following motors has the highest torque?
a)
three phase
b)
shaded-pole
c)
permanent-split capacitor
d)
capacitor start induction run
34.
What is the piston displacement of a compressor with a 2-inch bore and a 3-inch stroke?
a)
9.42 cubic inches
b)
12.00 cubic inches
c)
14.14 cubic inches
d)
37.70 cubic inches
35.
Natural gas has an approximated heating valvue of ______ Btu/cubic ft.
a)
2000
b)
1200
c)
1000
d)
750
36.
A technician needs to replace refrigerant R-502 in a system. The refrigerant SHOULD NOT be replaced with ___.
a)
R-22.
b)
R-507A.
c)
R-407A.
d)
R-407B.
37.
In regards to HVAC and air filters: Filters shall be installed in the return air system, in the ____ and in an approved convenient location.
a)
upstream from any heat exchanger or coilo
b)
downstream from any heat exchanger or coil
c)
supply air plenum
d)
supply air duct
38.
Refrigerants are composed of chlorine, fluorine, and carbon, and are referred to as chlorofluorocarbons or CFC's. Which of the following is NOT a chlorofluorocarbon?
a)
R-11
b)
R-22
c)
R-115
d)
R-503
39.
The ____ is located in the low side of the refrigeration cycle.
a)
evaporator
b)
cylinder unloaders
c)
compressor discharge line
d)
condenser
40.
A ____ cause(s) a rumbling noise from an electric motor.
a)
leaky oil port
b)
bad bearings
c)
unbalanced fan
d)
bad stator
41.
What is static pressure plus velocity pressure?
a)
total air pressure
b)
fricition loss
c)
fricition rate
d)
forced draft
42.
At what condition will moisture in air begin to condense?
a)
boiling point
b)
super heat
c)
dew point
d)
specific heat
43.
International fuel gas code emphasizes that the test pressure in gas piping to be used shall be AT LEAST ___psig.
a)
20
b)
40
c)
3
d)
10
44.
What is the effect on heat flow through insulation when the insulation thickness is doubled?
a)
heat flow is cut in half
b)
heat flow is reduced by one-fourth
c)
heat flow will double
d)
heat flow is reduced by one-third
45.
Indicate the correct answer when dealing with a two-pipe hydronic system:
a)
each pipe circuit is the same length in a reverse return system.
b)
a direct return system is easier to balance.
c)
each circuit is a different design in a reverse return system.
d)
less piping is required for a reverse return system.
46.
If a system is using 12" round flexible duct, what would be the air celocity measurement expressed in feet per minute (fpm) given that the air traveling through the duct is at a velocity of 600CFM?
a)
637 fpm
b)
763 fpm
c)
873 fpm
d)
936 fpm
47.
Factory-made air ducts NOT installed as a liner inside concrete, tile, or a metal pipe, shall be kept at least ____ inches away from earth.
a)
2
b)
4
c)
8
d)
12
48.
A low pressure control is wired in series with a thermostat and motor starter. When the thermostatic expansion valve is stuck in the closed position it
a)
allows the unit to remain running
b)
operates on a short cycle
c)
is not affected
d)
cuts out and the motor is turned off
49.
Absolute pressure is gauge pressure plus the atmospheric pressure which is expressed in ___.
a)
total inches of measure
b)
pound force per square inch
c)
pounds per square area
d)
pounds per square inch gage
50.
Select one of the most common result produced by a small difference in a system.
a)
short cycling
b)
temperatures that are too low
c)
long off periods
d)
an iced coil
51.
In hydronic systems, a closed expansion tank should have an automatic or manual air vent located ____.
a)
at the farthest point from the pump
b)
at the high point of the system
c)
at the low side of the system
d)
at the highest pressure point
52.
What type of circuit has only a single path for current to flow?
a)
parallel circuit
b)
series circuit
c)
low voltage circuit
d)
high voltage circuit
53.
Coverings and linings, including adhesives when used, shall have a flame spread index of NOT MORE THAN ____.
a)
250
b)
50
c)
25
d)
10
54.
A filter that can remove solid particles, odor causing gases, and bacteria is made of
a)
HEPA
b)
polyester
c)
fiberglass
d)
activated carbon
55.
Choose the correct item that is used to control capacity on commercial compressors:
a)
oil pumps
b)
blower speed
c)
unloaders
d)
pressure regulating valves
56.
Type IV and V systems in a dry cleaning plant shall be provided with an automatically activated exhaust ventilation system capable of maintaining a MINIMUM of how many feet per minute of air velocity through the loading door when the door is opened?
a)
100 fpm
b)
200 fpm
c)
400 fpm
d)
500 fpm
57.
A nominal pipe size of 6-inch gas pipe needs to be purged with inert gas prior to servicing. What is the length of piping requiring purging?
a)
greater than 10 feet.
b)
greater than 15 feet.
c)
greater than 20 feet.
d)
greater than 30 feet.
58.
What instrument is used to measure the power consumed by an electric motor or device?
a)
voltmeter
b)
ammeter
c)
wattmeter
d)
galvanometer
59.
The definition of ____ is the movement of heat from one place to another by way of a liquid (fluid) or gas.
a)
convection
b)
conduction
c)
radiation
d)
transformation
60.
When calculating the capacity of an existing commercial refrigeration evaporator, what performance data should be considered?
a)
high side pressure, subcooling and superheat
b)
heat load, area to be cooled and ambient temperature
c)
low side pressure, condensing cooling medium, and size of compressor
d)
compressor capacity, suction line temperature and temperature difference across the evaporator
61.
What condition does the automatic expansion valve maintain?
a)
constant pressure in the low side
b)
constant pressure in the condenser
c)
constant pressure in the high side
d)
constant temperature in the evaporator
62.
A filter drier should be cut out of a system rather than using a torch because
a)
it does a quicker job.
b)
tubing cutters are safer to use.
c)
prevents the possibility of flash gas from an ignition source.
d)
heat from the torch could drive moisture from the drier back into the system.
63.
The refrigerant flow through an automatic expansion valve is controlled by the:
a)
sensing bulb temperature
b)
sensing bulb pressure
c)
evaporative pressure
d)
evaporative temperature
64.
A client is requesting you to install a high heat metal chimney of 18 inches in diameter. For this job you will need to use sheet metal of ___ GA deep, AT LEAST.
a)
10 GA
b)
16 GA
c)
14 GA
d)
12 GA
65.
Calculate what the current draw would be given that a circuit is operating on a source voltage of 120 VAC, and has a single resistive load of 24 Ohms?
a)
120
b)
10
c)
5
d)
0.5
66.
Identify the INCORRECT method for joints in plastic fuel gas piping:
a)
heat-fusion
b)
threaded
c)
in accordance with NFPA 58
d)
compression type, mechanical joints
67.
What should be done to hard drawn of brittle copper before it can be flared?
a)
slightly swage the tubing
b)
anneal the copper tubing
c)
form a double-thickness flare
d)
clean and de-burr the inside of the tubing
68.
When equipment is located on the roof of an existing single-story building, permanent access is required if the roof exceeds ____ feet above the ground.
a)
14
b)
16
c)
24
d)
30
69.
The International Mechanical Code considers a "flammable vapor" to be concentration of flammable constituents in the air which exceeds ___ percent of its flammability limit.
a)
10
b)
15
c)
25
d)
30
70.
The two types of heat transfer surfaces in a heat pump system are located inside the
a)
compressor and metering device
b)
return and supply air ducts
c)
liquid line and in the suction line
d)
conditioned space and out-of-doors
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