Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: 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
2: There can be no airflow from an occupied space through a machine room unless what?
System is high velocity
System is ducted and sealed
Duct is not located in the ceiling
None of the above.
3: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
9.776 watts
977.6 watts
9,776 watts
.9776 watts
4: Name an HCFC refrigerant(s):
R-22
R-123
R-11
both a & b
5: Ammonia can come in contact with _______ ?
Brass
Copper tubing
Aluminum
Copper
6: Where is an EPR valve located on a multi-evaporator system?
Suction line of the coolest evaporator
Suction line of the warmest evaporator
Suction line prior to the accumulator of the lowest temperature system
Suction line at the compressor
7: A 3-cubic foot receiver must have what type of relief valve?
fusible plug
relief valve
rupture device
none of the above
8: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
.8
.1
1.2
1.7
9: A room having machinery but no flame producing apparatus permanently installed and operated is considered a
Class M machinery room
Class T machinery room
Class A machinery room
Class B machinery room
10: Pressure vessels having an inside diameter of 6” or less shall be protected by
a fusible plug
Pressure vessels having an inside diameter of 6” or less need no such protection unless otherwise specified
either a fusible plug or a pressure relief device
a pressure relief device
11: All welding done on any refrigeration system or piping covered by 522 CMR 9.00 shall be performed by a according to Section IX of the ASME code
licensed welder
competent welder
licensed technician
welder qualified
12: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
the vapor side of the system
the liquid side of the system
low side of the system
high side of the system
13: What is an example of institutional occupancy?
Shopping mall
Hospital
Football stadium
Dorms
14: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
350
250
400
100
15: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
2%
1%
4%
25%
16: "I" represents ____ in the Ohm's law formula.
capacitance
resistance
voltage.
amperage
17: The actual expansion curve of compressor follows most nearly which one of the following
Adiabatic
Isothermal
Volume
Pressure-Temperature
18: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
71 ohms
27 ohms
104 ohms
80 ohms
19: How much refrigerant can be stored in a mechanical room outside of the system?
200
330
150
100
20: What is not a requirement of a Class T machine room?
Self-closing doors
Fire hose connected to the building fire protection system.
Tight fitting doors
Automatic ventilation
21: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
77F
58F
70F
32F
22: _____ alloys shall not be used in contact with an halogenated refrigerants.
Zinc
Magnesium
Nickel
Copper
23: Which of the following is an example of an azeotropic refrigerant?
R-404A
R-410A
R-500
R-134A
24: Ammonia systems use ____ pressure to adjust oil pressure
discharge
liquid
stream
air
25: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are