Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: On a TXV, the purpose of an external equalizer is to?
allow a greater adjustment spam
balance the evaporator load
compensate for a pressure drop across the evaporator coil
Increase the pressure on the top of the power head diaphragm
2: What pipe can not be used for refrigeration?
K
N
L
M
3: 14.7 psia is equivalent to
atmospheric pressure at seal level
29.92" Hg
0 psig
All of the above.
4: Before replacing a seized compressor, the _______ should be determinded.
designed head pressure
cause of seizure
type of refrigerant
current draw
5: How many BTU's is produced by one watt of energy
1
2.57
3.41
3.00
6: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
critical pressure
high pressure
low pressure
design pressure
7: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.
75
15
50
55
8: Laten heat is associated with a change in state of a refrigerant but not temperature
True
False
9: Color is important in oil because
can tell us something about the refining of oil
allows you to see into crankcase
it indicates the viscoisty.
it makes sight glasses easy to read
10: A run capacitor is wired in series with the _____ windings.
run
common
start capacitor
start
11: What is the typical air conditioning operating pressures for R-22?
60 psi suction 210 psi discharge
25 psi suction 125 psi discharge
105 psi suction 340 psi discharge
None of the above
12: What device measures the specific gravity of a substance?
Hydrometer
Manometer
Thermometer
Hygrometer
13: Fusible plugs must have what marked on them?
Melting temperature in F
Melting temperature in C
Opening pressure
All of the above
14: Large vessels containing refrigerant ______________________ from using two or more pressure-relief devices in parallel to obtain the required capacity.
of Group B2 refrigerant shall be prohibited
containing R-11, R-123 & R-717 exclusively shall not be prohibited
shall be prohibited
shall not be prohibited
15: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
120v
240v
208v
277v
16: Horizontal piping should be run level.
True
No, unless the supervisor on the job says so.
Yes, if the condenser is located above the evaporator
False
17: When a receiver is greater than 3 cubic feet but less than 10 cubic feed, what is the minimum relief device required?
fusible plug
relief valve
rupture disc
all of the above
18: Fusible plugs shall not be used with pressure vessels of
15 cubic feet or more
3 cubic feet or more
15 square feet or less
3 cubic feet or less
19: What is R-22?
CCFCM
Chlorofluoromethane
HFC
Chlorodifluoromethane
20: Pressure vessels having an inside diameter of 6” or less shall be protected by
a fusible plug
a pressure relief device
either a fusible plug or a pressure relief device
Pressure vessels having an inside diameter of 6” or less need no such protection unless otherwise specified
21: How many CFMs are required per square foot of commercial office occupied space
5 CFM
20 CFM
.5 CFM
15 CFM
22: On a large centrifugal system, what meters the flow to the evaporator?
Cap tube.
Low side float
TXV
High side float
23: Where would the EPR valve be located on a multiple evaporator system?