Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: At higher altitudes, the boiling point of refrigerant is
lower
the same
equal to the coefficient of water at 32F
higher
2: On a large centrifugal system, what meters the flow to the evaporator?
High side float
TXV
Low side float
Cap tube.
3: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
506v
550v
660v
None of the above
4: What is NOT a positive displacement compressor.
Centrifugal
Scroll
Rotary
Reciprocating
5: The discharge relief valve is located (9.4.6)
between the compressor and reciever
between the compressor and the stop valve
between the compressor and oil separator
on top of the condensor
6: Gauge pressure is
atmospheric pressure
what a gauge reads when checking pressures on a chilled water system.
force of pressure above that of atmospheric
absolute pressure
7: What does safe access mean?
Well-lit exit signs
A clear unobstructed path to the equipment and controls
Locked doors
OSHA approved
8: 1 Watt = ______ BTU's?
3.412
12
7.216
4.482
9: If a purge unit fails on a low pressure chiller, what are the symptoms?
low pressure chillers do not have purge units
high head pressure
low suction pressure
increased capacity
10: What is the purpose of a surge capacitor on a contactor?
to provide smoother start/stops
to protect low voltage equipment
to keep the contactor pulled in
to balance the sine waves
11: 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
boiler
compressor
evaporator
outside the machinery room
12: In a refrigeration system, you open a valve from the condenser and collect some material on a clean white sheet of bond paper, which of the following would you most likely be testing for?
checking the level of refrigerant in the system
testing for oil in the system
testing for moisture in the system
none of the above
13: How many forces operate a thermostatic expansion valve?
3
2
4
1
14: The evaporator is a device to
absorb heat into the refrigeration system
remove heat from the refrigeration system
Keep the compressor busy
store liquid refrigerant
15: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
58F
77F
32F
70F
16: Low-side system leaks in a low-pressure chiller will often result in
system refrigerant leaking from the system
nitrogen leaking out of the system.
air being pulled into the system
water being pulled into the system
17: How many refrigerant classifications are there for flammability?
7
1
2
3
18: 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
19: Transformers are rated in
volt-amps
volts-ohms
volts
amps
20: 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.
15
55
50
75
21: Low pressure chiller systems use what type of compressor?
Centrifugal
Scroll
Reciprocating
Screw
22: What type of voltage causes the winding in a potential relay to open?
BEMF (Back Electro-Motive Force)
24V control voltage from the thermostat
120V line voltage
None of the above
23: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
66
25
50
22
24: 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)?
printed circuit board (PCB)
duel-voltage switch
motor starter
centrifugal switch
25: Liquid line filter-driers on a 410A system must be rated for no less than