Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: How many closing forces operate a thermostatic expansion valve?
4
1
2
3
2: How can you test mechanical strength of an electrical connection?
measure ohms with an electrical meter
measure voltage across the connection
attempt to pull the wire from the connector by hand
none of the above.
3: Give an example of a secondary coolant?
R-12
R-718
R-410A
R-717
4: Pressure is equivalent of
Force / Area
Force
Force X Area
Area X Force
5: R22 and 410A operate at the same range of condensing and evaporating temperatures
true
false
6: When using nitrogen for brazing, the pressure should be:
Very low
Slightly below atmospheric
125 psig
50-100 psig
7: 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
15
50
55
8: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
drawing RLA and is running as it should
drawing LRA and is seized and should be replaced.
running hot
none of the above
9: When can 50/50 solder be used?
in the low side
in the high side
liquid and suction lines
none of the above.
10: Emergency shutdown procedures, including precautions to be observed in case of a breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a conspicuous card located as near as possible to the
evaporator
compressor
boiler
outside the machinery room
11: What type of relief valve is used on a CO2 system?
glove disc
gate valve
rupture disc
fusible plug
12: How many flammability classifications are refrigerants in?
2
5
3
7
13: Halogenated refrigerants cannot be used with what material?
Copper
Stainless steel
Magnesium alloy
Aluminum
14: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are
gate or globe valves
companion or block valves
ball valves
king valves
15: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
When it's cold out
When there is a malfunction on the high side
When its warm out
All of the above
16: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
“UM” and “UV”
“UV”
“UL”
“U” or “UM”
17: What kind of system uses two different refrigerants in separate systems dependent on each other?
Low pressure
R-414B
Simple
Cascade
18: The formula for Pure Power in a resistance circuit is
Watts X amps.
Kw = volts X amps
Watts X power factor
Watts = volts X amps
19: 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
20: Can ammonia be used on domestic system?
no, unless there is proper ventilation system installed
yes, for systems under 10 tons
no
yes
21: An example of direct system is
rooftop unit
chiller
absorber
none of the above
22: A factory-sealed system containing less than 22lbs. of Group A1 refrigerant
shall have a pressure limiting device installed on the high side of the system
shall have a pressure limiting device and a pressure relief valve installed
does not require a pressure-limiting device
shall be inspected by the Boiler of Inspectors bi-annually
23: R-410A can segregate in the system or chemically change its composition due to a leak.
True
False
24: Doors communicating with outside from a mechanical room must be?
Self-closing, approved, fire door
Self-closing, wooden, fire door
Steel, approved, weather-stripped
Self-closing, aligned, fire door
25: Booster compressors, pump refrigerant into the