Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The evaporator is a device to
Keep the compressor busy
remove heat from the refrigeration system
store liquid refrigerant
absorb heat into the refrigeration system
2: What is the minimum height refrigeration piping should be placed against walls?
72"
6'
7.25'
Ceiling height
3: If the power element on an expansion valve should lose its charge, the valve would
Over feed
Under feed
Stay open
Close
4: How many CFMs are required per square foot of commercial office occupied space
15 CFM
5 CFM
.5 CFM
20 CFM
5: The Department that certifies the transportation of refrigerant is the
RSES
EPO
DOT
EPA
6: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
2%
1%
4%
25%
7: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
commercial occupancy
mixed occupancy
public assembly occupancy
institutional occupancy
8: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
Make sure its compatible, notify owner, and notify AHJ.
you can never change refrigerants
Nothing must be done
Place sign, check for leaks, and insulate suction line
9: What is the leaving chilled water set point for water chiller systems?
38F
45F
66F
55F
10: Refrigerants shall be classified by
toxicity and flammability
requirements for commercial, industrial, and residential occupancies
maximum permissible quantities of each group
color codes
11: Brazed joints melt at temperatures above
1,200F
500F
1,000F
800F
12: Methyl Chloride is a halogenated refrigerant and should not come in contact with
aluminum
zinc
magnesium
all of the above
13: The measurement of heat in a particular substance is
specific heat
enthalpy
latent heat
sensible heat
14: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
500 lbs
330 lbs
660 lbs
55 lbs
15: Evaporators within 18" of a heating coil must be equipped with a
high limit control
low limit control
zone valve
pressure relief device
16: Ammonia systems use ____ pressure to adjust oil pressure
discharge
liquid
stream
air
17: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
R-113
R-22
R-11
R-12
18: Capacity control on a centrifugal compressor is accomplished by the
pre-rotational guide vanes
slide vanes
check valves
post-rotational guide vanes
19: The first step in mechanical refrigeration is
condensation
expansion
compression
evaporation
20: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
splurge
surge
purge
merge
21: A halide torch is most useful with a freon compression system
to detect refrigeration leaks in piping joints
to remove from from TXV's and evaporator coils
to sweat flanges on the refrigeration piping
to release a sticking valve
22: Pressure vessels with an internal volume of 10 cubic feet or more
shall use rupture discs or duel pressure relief valves
shall use pressure relief devices
shall use pressure relief devices or fusible plugs
shall use fusible plugs
23: Pressure is the equivalent of
force per unit area
area times force
force
force times area
24: Ammonia vaporization takes place at what temperature?