Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The leaving chilled water set point for comfort cooling is typically?
60
66
45
38
2: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.
7.00'
7.25'
8'4"
9.00'
3: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
Positive displacement
Low Pressure displacement
Non-positive displacement
Pressure induced displacement.
4: A tachometer is an instrument used to measure
speed
air velocity
static pressure
RPM
5: The Board of Boilers adopts by reference
MSCA Code
Montreal Protocol Safety Code
the MACS Pressure Vessel Code of Massachusetts
the 1997 ANSI/ASHRAE Safety Code
6: 14.7 psia is equivalent to
atmospheric pressure at seal level
29.92" Hg
0 psig
All of the above.
7: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
Muffler
Moisture indicator
Foot valve
Stop valve
8: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
455 psig, 185 psig.
257 psig, 77 psig
226 psig, 68 psig
365 psig, 120 psig
9: The first step in mechanical refrigeration is
expansion
compression
evaporation
condensation
10: 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.
11: Where must a refrigeration contractor's license number be displayed?
Truck, office, every job, and on all equipment
Trucks, license plates, and uniforms
Trucks, invoices, and advertising
Uniforms, checks, and invoices.
12: A normal operating evaporator temperature of R-22 for air conditioning is typically
32F
58F
45F
55F
13: Trichlorofluoromethane is the name of what refrigerant?
R-502
R-11
R-12
R-113
14: 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
15: What effect does the temperature of air have on humidity?
warmer air holds more moisture then cooler air
cooler air holds more moisture then warmer air
air has no effect of humidity
none of the above
16: What is the minimum height refrigeration piping should be placed against walls?
72"
6'
Ceiling height
7.25'
17: What is potential measured in?
Ohms
Henrys
Volts
Amps
18: A class B2 refrigerant is considered
non-toxic and non-flammable
toxic and non-flammable
non-toxic and highly flammable
toxic and somewhat flammable
19: Pressure vessels with an internal volume of 10 cubic feet or more
shall use pressure relief devices or fusible plugs
shall use pressure relief devices
shall use rupture discs or duel pressure relief valves
shall use fusible plugs
20: When an inspection is needed, how often must it be done?
every 24 months
every 36 months
every 18 months
annually
21: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
A group sensing
phosgene gas sening
CO Sensing
refrigerant sensing
22: On a centrifugal compressor, stationary diffuser vanes are needed to
increase the clearance space
convert velocity energy to pressure
stop gas flow
prevent high pressure on the packing
23: An oil pressure safety switch should be set at
5 to 10 psi above low side pressure
5 to 10 psi below low side pressure
10 to 15 psi below low side pressure
10-15 psi above low side pressure
24: A relief valve discharge capacity is rated in
temperature minus pounds of air per second divided by release rate squared