Topics: All categories in the pool
1: An example of direct system is
- rooftop unit
- chiller
- absorber
- none of the above
2: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
3: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
4: Viscosity is
- the ability of oil to flow
- measure of weight
- a measure of heat content
- the coefficient of external friction
5: What is not a requirement of a Class T machine room?
- Tight fitting doors
- Self-closing doors
- Fire hose connected to the building fire protection system.
- Automatic ventilation
6: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 50
- 66
- 22
- 25
7: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- duel-voltage switch
- motor starter
- centrifugal switch
- printed circuit board (PCB)
8: Heat transferred by conduction from one body to another is done
- via liquids
- via heat rays
- via solids
- via radiation
9: How many CFMs are required per square foot of commercial office occupied space
- 15 CFM
- 20 CFM
- 5 CFM
- .5 CFM
10: Ammonia systems use ____ pressure to adjust oil pressure
- liquid
- air
- discharge
- stream
11: B3 refrigerants are considered
- toxic and highly flammable
- non-toxic but non-flammable
- toxic but non-flammable
- non-toxic but flammable
12: Clearance volume
- is the same on all compressors
- affects compressor capacity
- has no effect on compressor capacity
- varies depending on compressor speed
13: While the system is operating, the discharge line should be
- 10-15F warmer than ambient
- room temperature
- too hot to hold by hand
- at the same temperature as the crankcase
14: How many groups of refrigerants are there?
- 1
- 7
- 3
- 5
15: The actual expansion curve of compression follows most nearly which one of the following curves?
- Pressure Temperature
- Isothermal
- Adiabatic
- Volume Temperature
16: In a horizontal shell & tube condenser, the ammonia is liquefied by
- water sprayed over condenser
- passing thru the tubes from top to bottom
- removing the latent heat of fusion
- removing the latent heat of vaporization
17: 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 fan and circulating pump
- start the comrpessor
- reset the safety valve
18: Ammonia is under what safety classification?
- B3
- A3
- B2
- B1
19: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
- drawing RLA and is running as it should
- drawing LRA and is seized and should be replaced.
- running hot
- none of the above
20: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
21: If the power element of an expansion valve should lose its charge the valve would
- underfeed the evaporator
- overfeed the evaporator
- go open
- go closed
22: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
- it would cause the condenser to sweat
- it would make the condenser less efficient
- it would make the condenser more efficient
- it would have no effect on the condenser
23: At higher altitudes, boiling temperatures
- depends on the refrigerant
- are unaffected
- decrease
- increase
24: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or more
- 15 cubic feet or more
- 3 cubic feet or less
- 15 square feet or less
25: One atmosphere equals
- 0 psig
- 29.4
- 0 psia
- 14.7