Topics: All categories in the pool
1: What must be done if refrigeration lines pass through a concrete floor?
- installed through a pipe casing
- leak checked
- moisture barrier
- insulated
2: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 50
- 18
- 33
3: A rule of thumb in air conditioning is ____ CFM per ton?
- 500
- 100
- 600
- 400
4: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Simple
- R-414B
- Low pressure
- Cascade
5: A split-phase motor has a ______ winding and a ____ winding
- duel-run, duel-start
- run, start
- run, common
- start, common
6: Pressure vessels having an inside diameter of 6” or less shall be protected by
- either a fusible plug or a pressure relief device
- a fusible plug
- Pressure vessels having an inside diameter of 6” or less need no such protection unless otherwise specified
- a pressure relief device
7: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- are obsolete.
- depends on the type of refrigerant being used
- True
- False
8: 1 HP = ____ Watts?
- 3.1416
- 3,412
- 746
- 11,239
9: What must be done to all doors and access points in duct work going through a mechanical room?
- Must be hindged
- Must be screwed shut
- Must be sealed and gasketed
- All of the above
10: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?
- R-718 is not rated unlimited because it's a dangerous refrigerant
- Because it's water
- Because it's a non-flammable refrigerant
- Because it's cheap
11: A premise or that portion of a premise where people transact business, receive personal service, or purchase foods, other goods is considered a
- commercial occupancy
- public assembly occupancy.
- mercantile occupancy
- business occupancy
12: Increasing superheat will do what to your frost line?
- Decrease
- Nothing
- Increasae
- Could either increase or decrease depending on the load conditions
13: 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
- 50.2 psig
- 70.8 psig
- 43.3 psig
14: Class 3 refrigerants are
- highly flammable
- toxic
- non-flammable
- non-toxic
15: What type of relief valve is used on low pressure centrifugal compressor systems?
- Spring-loaded relief valve
- Rupture disc
- Purge relief
- None of the above
16: Where would the EPR valve be located on a multiple evaporator system?
- outlet of high temperature evaporator
- inlet of the low temperature evaporator.
- outlet of low temperature evaporator
- outlet of the liquid line
17: A capacitor in series with the start windings will do what?
- Increase starting torque
- Decrease the RLA to within 10% of its rating
- Nothing
- Increase run efficiency by 10% of its rating
18: Adjusting the spring pressure on a TXV
- adjusts the bulb charge
- changes subcooling
- makes no difference
- changes superheat
19: R-12. R-22, and R-40 are considered Group I refrigerants.
- True
- False
20: When can recovered refrigerants be reused?
- They can't
- Only when used in original owner's equipment
- Only if used in 30 days of recovery
- None of the above
21: What is the leaving chilled water set point for water chiller systems?
- 55F
- 45F
- 66F
- 38F
22: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 110
- 1,000
- 330
- 6.6
23: A hissing noise at the expansion valve is a good indication that
- liquid is passing thru it
- nothing is passing thru
- expansion valve is oversized
- gas is passing thru it
24: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
25: B3 refrigerants are considered
- non-toxic but flammable
- toxic and highly flammable
- toxic but non-flammable
- non-toxic but non-flammable