Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The discharge relief valve is located (9.4.6)
between the compressor and the stop valve
on top of the condensor
between the compressor and oil separator
between the compressor and reciever
2: Booster compressors, pump refrigerant into the
heat & plate heat exchanges
low side of the primary compressor
high side of the secondary compressor
receiver
3: 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
4: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
277v
240v
120v
208v
5: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
moisture in the system
oil in evaporator
low head pressure
not enough oil in the system
6: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
.8
1.2
1.7
.1
7: A thermometer inside a duct measures ____ heat.
latent
hidden
sensible
specific
8: 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
9: A motor starter is a device that includes an overload and a _______?
contactor
2-pole contacts
duel-coil
all of the above
10: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
88
116
108
38
11: How are a compressor and condenser fan wired?
parallel-series
parallel
series-parallel
series
12: "I" represents ____ in the Ohm's law formula.
amperage
capacitance
resistance
voltage.
13: No open flames are allowed in the machinery room unless?
Approved by the authorized person
Approved by the installing contractor
Never can be allowed
Only when combustion air is provided from outside of the machinery room
14: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
66.1 psig
43.3 psig
50.2 psig
70.8 psig
15: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
opening at the pump inlet
cooling temperature set-point
opening at the pump outlet
adjustment of the spring tension of the TXV
16: Ammonia vaporization takes place at what temperature?
-32F
-110F
-28F
-460F
17: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.
True
False
18: Pipe identification labels are required when the system contains more than
65 lbs
120 lbs
55 lbs
110 lbs
19: R-12. R-22, and R-40 are considered Group I refrigerants.
True
False
20: What refrigerant has zero ozone depletion
HFC
CFC
HCFC
None of the above
21: In designing duct work, pressure and ______ need to be considered
length
CFM
duct sealant used
all of the above
22: The low pressure oil safety switch
never trips
must be reset manually
resets itself automatically
resets itself after the time delay has terminated
23: Usually dry bulb temperature is
not important and shall be ignored
higher than wet bulb temperature
same as wet bulb temperature
lower than dry bulb temperature
24: Start to Run windings will have what resistance?
The least resistance value
Somewhere between the actual start winding and run winding resistance value
All will be at equal values
The most resistance value
25: Doors communicating with outside from a mechanical room must be?