Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: How many different groups of refrigerants are there?
3
15
7
11
2: In a system designed for sub-zero ambient temperatures, what must be added?
Nitrogen
Low-ambient kit
Infrared dye for leak identification
Booster compressor
3: What is Trichlorotrifluoromethane?
R-11
R-113
R-13
R-12
4: If the power element of an expansion valve should lose its charge the valve would
go closed
overfeed the evaporator
go open
underfeed the evaporator
5: According to ASHRAE Standard-15 9.8 Positive Displacement Compressor Protection, the pressure-relief device discharge into
the low-pressure side of the system
the high side of the system
the liquid receiver
both a and c are correct
6: What is the temperature that a liquid and a vapor can exist in equilibrium called?
Saturated temperature
Critical temperature
Wet bulb temperature
Dry bulb temperature
7: Who authorizes changes to the safety codes?
Person in charge of the facility
Person who pulled the permit
Board of Boilers
Contractor who last serviced the system.
8: What type of relief valve is used on a CO2 system?
gate valve
glove disc
fusible plug
rupture disc
9: What is the boiling point of refrigerant governed by?
P&T relationship
Compressor RPM's
Evaporator temperature
Condenser sub-cooling
10: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
660 lbs
500 lbs
55 lbs
330 lbs
11: All machine rooms must be outfitted with a detector that _______?
activates an audible alarm
activates a visual alarm
starts the ventilation system
All of the above
12: All low-pressure chillers use which type of compressor?
Reciprocating
Rotary
Scroll
Centrifugal
13: A class B1 refrigerant is considered
non-toxic and non-flammable
toxic but non-flammable
non-toxic but highly flammable
toxic and somewhat flammable
14: Halogen refrigerants are corrosive to which type of metal?
copper
stainless steel
magnesium
black iron
15: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
True
False
16: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
99%
90%
80%
75%
17: Which oil is hydoscopic?
SW30
polyolester
mineral
animal
18: Copper and its alloys shall not be used with ammonia
True
False
19: In a motor, an internal overload might open if
there's an excess current draw through the motor
there was a high pressure refrigerant was used for a low pressure system.
there's an open start winding
there's a direct short
20: In designing duct work, pressure and ______ need to be considered
length
CFM
duct sealant used
all of the above
21: What type of material can't be used on the outlet of a relief valve?
Magnesium alloy
Copper
Stainless steel
PVC
22: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
first disconnect in
breaker panel in
24 volt secondary side of the Class 2 transformer to the thermostat
load-side of the contactor in
23: A single pole-double throw switch uses how many wires?(excluding the ground)
5
4
2
3
24: 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
25: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
sight glass, weight, paper method, and frost line.