Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: 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)
2: Give an example of a secondary coolant?
R-12
R-410A
R-717
R-718
3: Which of the following controllers would you expect to be most sensitive to temperature changes?
aquastat
immersion controller
line voltage t-stat
low voltage t-stat
4: What is the minimum height refrigeration piping should be placed against walls?
6'
Ceiling height
72"
7.25'
5: The purpose of a receiver is
a vessel to store refrigerant outside the system
to increase the capacity that the system can hold
to use a a later date
all of the above
6: Clearance volume
varies depending on compressor speed
has no effect on compressor capacity
affects compressor capacity
is the same on all compressors
7: 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
8: What section governs pressure vessels?
Section 1 ASHREA 15 ASME fired
Section ASHREA 34
OSHA
Section 8 ASHREA 15 ASME unfired
9: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
A group sensing
refrigerant sensing
CO Sensing
phosgene gas sening
10: How far from the window does a relief valve need to be according to ASHRAE-15?
There is no minimum for relief valve and windows.
At least 40'
At least 30'
At least 20'
11: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
55 lbs
500 lbs
660 lbs
330 lbs
12: What type of relief valve is used on low pressure centrifugal compressor systems?
Spring-loaded relief valve
Rupture disc
Purge relief
None of the above
13: Capacity control on an absorption system is typically accomplished by varying the
speed of the condenser water circulator pump
speed of the chilled water circulatory pump
rate at which heat is supplied to the generator
pressure setting on the system's rupture disc
14: 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
15: The Board of Boilers adopts by reference
the 1997 ANSI/ASHRAE Safety Code
the MACS Pressure Vessel Code of Massachusetts
MSCA Code
Montreal Protocol Safety Code
16: Bubbles in the liquid line sight glass could be caused by
overcharge of oil
bad low pressure switch
leaking discharge valves in the compressor
plugged drier
17: A direct system
is a self-contained complete factory made and tested system
is one which encloses a separate body of evaporative refrigerant
is where the refrigerant comes in contact with the space refrigerated
is on where brine is cooled & circulated to the space refrigerated
18: The normal operating evaporator temperature of R-410A for air conditioning is typically
32F
45F
158F
155F
19: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
1%
4%
2%
25%
20: Electricity involves the movement of electrons in atoms
True
False
21: When an A/C system is excessively low on refrigerant
it can become contaminated with water
there can be nuisance trip outs
the suction line may be too hot to touch
All of the above
22: pressure relief valves must discharge to the atmosphere at a location not less than 15 feet from ground level and ____ feet from any window, ventilation opening, or exits of buildings.
10
15
20
25
23: 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
24: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
660 lbs
55 lbs
550 lbs
330 lbs.
25: How many BTU's is produced by one watt of energy