Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
high side of the system
the liquid side of the system
low side of the system
the vapor side of the system
2: If your suction line is warmer than the room temperature, this may indicate
an over charge
below normal superheat
plugged air filter
a low charge
3: 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
24 volt secondary side of the Class 2 transformer to the thermostat
breaker panel in
load-side of the contactor in
4: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
50
33
22
18
5: Class A refrigerants are considered
toxic
non-flammable
non-toxic
flammable
6: When using nitrogen for brazing, the pressure should be:
Slightly below atmospheric
Very low
50-100 psig
125 psig
7: What is the minimum size of the discharge pipe?
Same size as the outlet of the relief valve
One pipe size larger that the inlet of the relief valve
Depends on size of manifold
All of the above
8: What is Trichlorotrifluoromethane?
R-11
R-13
R-12
R-113
9: A mixed occupancy occurs when two or more occupancies are located with the same building
true
false
10: 746 watts is equal to
1 hp
Pi
100 hp
10 hp
11: Which of the following types of oils are hygroscopic?
polyolester (POE)
polyalkylene glycol (PAG)
naphthene mineral
both a and b
12: In designing duct work, pressure and ______ need to be considered
length
CFM
duct sealant used
all of the above
13: R-22 falls under which safety classification?
B-1
B-2
A-2
A-1
14: Who authorizes changes to the safety codes?
Person in charge of the facility
Contractor who last serviced the system.
Board of Boilers
Person who pulled the permit
15: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
R-718
trichlorotrifluoromethane
ammonia
methyl chloride
16: Suction valve unloaders afford an effective means of
capacity control
evaporator control
superheat control
refrigerant control
17: What is the refrigerant dichlorodifluoromethane?
R-123
R-22
R-12
R-134A
18: "I" represents _______ in the Watt's law formula.
voltage
amperage
watts
reactance
19: Lithium-bromide, Li-Br, is best characterized as a
sand
salt
soil
sugar
20: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
77F
58F
32F
70F
21: How much refrigerant can be stored in a mechanical room outside of the system?
150
100
330
200
22: What is the minimum size wire you can use on a 30 amp circuit?
10 AWG
16 AWG
12 AWG
14 AWG
23: In an air conditioning plant which an indirect low side, water is used inside of bring: the proper sequence of operating the plan is
reset the expansion valve
start the comrpessor
reset the safety valve
start the fan and circulating pump
24: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
5.5
2.5
3.0
2.0
25: All machine rooms must be outfitted with a detector that _______?