Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
24.0 volts
2,400 volts
240 volts
2.40 volts
2: R-22 is considered a(n)
CFC
HFC
HCFC
HCFCH
3: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?
RPM and CFM increase
CFM and HP increase
CFM and RPM decrease
CFM and HP decrease
4: Transformers are rated in
volt-amps
volts
volts-ohms
amps
5: Where are the three places that the discharge from an ammonia relief valve be piped?
atmosphere, tank containing water, where the A.H.J. indicates
underground, into drain, into mechanical room
to chemical neutralizing tank only
none of the above
6: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
low head pressure
oil in evaporator
moisture in the system
not enough oil in the system
7: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
2.5
There isn't enough information to answer.
1250
2
8: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
660 lbs
55 lbs
500 lbs
330 lbs
9: Oils, classified as to source, are
naphthalene, mixed, and paraffin
animal, vegetable, and mineral
naphthalene, paraffin, and castor
animal, vegetable, and castor
10: A machine room with a refrigerant system using ammonia shall
be provided with a continuously operated ventilation system
be considered a non-hazardous location in accordance with National Electrical code
have no flame producing apparatus permanently installed and operated
All of the above
11: A moisture indicator must
change color when exposed to moisture
be filled with liquid
be sight side up
be yellow
12: The high side float assembly meters refrigerant into the evaporator through the
lower chamber of the high side
upper chamber of the high side
upper chamber of the low side
lower chamber of the low side
13: Which refrigerant class listed below is the most flammable?
A-1
C-3
B-2
A-3
14: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
746 watts
1000 watts
600 watts
5KW
15: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
1.2
.8
1.7
.1
16: Which refrigerant class listed below is the most flammable?
C3
B2
A2
A3
17: 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
18: By using nitrogen within a pipe during brazing operation,
Copper oxide formation is prevented
Exterior scale formation is minimized
The explosion hazard is confined
Discoloration is prevented
19: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
2F difference
a ling psychrometer doesn't have two theremometers.
far apart or greater difference
nearly the same
20: What is not a requirement of a class T machine room?
self-closing doors
fire hose connection to the building fire protection system
tight fitting doors
automatic ventilation
21: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
977.6 watts
9,776 watts
.9776 watts
9.776 watts
22: What must be done to refrigerant pipes before being buried ?(8.10.4)
Leak checked
Classifed
Insulated and installed in a pipe duct (Encased)
Certified
23: A water regulating valve opens when
when the power is on there is an overcharge of refrigerant
the head pressure rises
the compressor is on
when the power is on
24: Which occupancy can ammonia be used in?
industrial
commercial
depends on the quantity of freon
redifential
25: How many opening forces operate a thermostatic expansion valve?