Topics: All categories in the pool
1: The two basic types of evaporators are
- finned and plate
- direct expansion and plate
- flooded and direct expansion
- prime surface and finned
2: The Department that certifies the transportation of refrigerant is the
- EPA
- EPO
- DOT
- RSES
3: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
4: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
5: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- pick-up voltage
- lift voltage
- run voltage
- boost voltage
6: An oil pressure safety switch should be set at
- 5 to 10 psi above low side pressure
- 10-15 psi above low side pressure
- 10 to 15 psi below low side pressure
- 5 to 10 psi below low side pressure
7: An example of direct system is
- rooftop unit
- chiller
- absorber
- none of the above
8: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
9: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Nesting scrolls
- Fan-like action
- Suction and discharge valves
- Rotating vanes
10: "E" references ____ in the Ohm's law formula
- voltage
- resistance
- capacitance
- amperage
11: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 10,000
- 100,000
- 1,000
- 100
12: The rupture disc on a low-pressure chiller typically releases pressure at
- 15 psig
- 5 psig
- 0 psig
- 10 psig
13: The purpose of an accumulator is to
- reduce friction loss to the flow of refrigerant
- store excess refrigerant from the reciver
- assure no liquid returns to the compressor
- filter out impurities from the system
14: Which occupancy can ammonia be used in?
- redifential
- depends on the quantity of freon
- industrial
- commercial
15: The color code of a tank of ammonia is
- silver
- white
- lavender
- light green
16: With a 5/8" X 5/8" x 3/4" tee, what size is the center connection?
- 3/4"
- 1/2"
- 5/8"
- 3/8"
17: Give an example of a secondary coolant?
- R-12
- R-718
- R-410A
- R-717
18: A capacitor in series with the start windings will do what?
- Decrease the RLA to within 10% of its rating
- Nothing
- Increase starting torque
- Increase run efficiency by 10% of its rating
19: What is a Category "D" fluid?
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
- A typical refrigerant used on newer air conditioning and heat pump ssytems
- Any fluid that exceeds 150 psig and has design temperature of over 366F
20: A self contained system
- is a unit system Group I refrigerants only
- is a complete factory made and tested system
- is any system or part of a system used to increase evaporation by expansion or vaporization
- is a unit system Group II refrigerants only
21: In an electrical circuit, what is potential measured in?
- Volts
- Ohms
- Amps
- Herys
22: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 20 amps
- 15 amps
- 10 amps
- 5 amps
23: "R" represents ___ in the Ohm's law formula
- voltage
- amperage
- resistance
- capacitance
24: Mercury was used in thermometers primarily because it
- was inexpensive
- never freezes
- expands uniformly
- vaporizes at very high temperatures
25: Name three things that must be done when changing refrigeration lubricant?
- Place sign, check for leaks, insulate
- Make sure it's compatible, notify owner, notify AHJ
- Nothing must be done
- You can't change lubricants.