Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: 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
2: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.
80
100
90
110
3: RPM's of a centrifugal compressor are at approximately?
15,000
10,000
500
30,000
4: Give an example of a secondary coolant?
R-12
R-410A
R-717
R-718
5: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
44 lbs
13.9 lbs
6.6 lbs
22 lbs
6: What is the temperature that a liquid and a vapor can exist in equilibrium called?
Wet bulb temperature
Dry bulb temperature
Critical temperature
Saturated temperature
7: Industrial occupancy is
a premise or that portion of a premise that is not open to the public, where access by authorized persons is controlled, and that is used to manufacture, process, or store goods, such as chemicals, food, ice, meat, or petroleum.
is a premise or that portion of a premise where large number of people congregate and from which occupants cannot quickly vacate the space.
a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
Both a and b are correct
8: The two basic types of evaporators are
flooded and direct expansion
finned and plate
direct expansion and plate
prime surface and finned
9: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
the owner shall be informed
no flames shall be permitted
explosion precautions must be taken
gas masks must be worn
10: A R-22 system running with a condensing temperature of 110F and a 40F evaporator temperature will read pressures of ____ on the high side and ____ on the low side.
226 psig, 68 psig
350 psig, 120 psig
455 psig, 185 psig
257 psig, 77 psig
11: Which of the following is NOT a positive displacement compressor?
scroll
screw
reciprocating
centrifugal
12: Defined process piping by code CMR (528)
Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
Any piping in an industrial space
Any piping in an industrial or commercial space
All of the above
13: "P" represents ______ in the Watt's law formula
voltage
watts
amperage
reactance
14: Liquid level gauges must be provided with what?
A low level mark
Automatic shut-offs
A relief valve
A red line
15: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
125 psig
327 psig
365 psig
255 psig
16: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
Flush with ammonia
Flush with R-718
Flush with RX-11
Flush with R-11
17: The reversing valve is commonly used
on multiple compressor systems
on all heat pumps
on commercial system that involve two different temperatures
when the code requires a check valve
18: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
centrifugal switch
duel-voltage switch
motor starter
printed circuit board (PCB)
19: 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
100
250
400
20: _____ and its alloys are suitable for use with ammonia systems.
Zinc
Copper
Magnesium
Aluminum
21: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
it is hydroscopic
it traps moisture
viscosity
all of the above
22: Pressure vessels with an internal volume of 3 cubic feet or less
shall use pressure relief devices
shall use fusible plugs
do not need pressure relief protection
shall use pressure relief devices or fusible plugs
23: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
the mechanical room housing the refrigeration system
the return air ducted system
Machinery rooms need not be vented
the outdoors
24: 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
55
15
50
25: What type of fuses must be used on a HVAC system?