Topics: All categories in the pool
1: 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
- 70F
- 32F
- 58F
2: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
3: Heat cannot of itself, pass from a
- cold to a warmer body
- warm to a colder body
- state of hot energy to a state of cold energy
- None of the above
4: An example of an "Expendable Refrigerant" is
- liquid nitrogen
- ammonia
- lithium bromide
- liquid oxygen
5: Can you use Ammonia in industrial applications?
- Yes, Under certain condidtions
- No, never
- When mixed with R-718
- Yes, always
6: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-1
- B-2
- A-2
- B-1
7: A motor starter contains a thermal overload and a
- contactor
- solenoid
- transformer
- 3-way relay
8: What must be done to refrigerant pipes before being buried ?(8.10.4)
- Classifed
- Certified
- Leak checked
- Insulated and installed in a pipe duct (Encased)
9: What is considered a cooling agent?
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without condensation
- any liquid used for the transmission of heat when vaporization occurs
- any liquid used for the transmission of heat without vaporization
10: On a centrifugal compressor, stationary diffuser vanes are needed to
- stop gas flow
- prevent high pressure on the packing
- convert velocity energy to pressure
- increase the clearance space
11: What is not a requirement of a Class T machine room?
- Fire hose connected to the building fire protection system.
- Automatic ventilation
- Tight fitting doors
- Self-closing doors
12: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 350
- 100
- 400
- 250
13: One atmosphere equals
- 0 psia
- 14.7
- 0 psig
- 29.4
14: Gauge pressure is
- Force of pressure above that of atmosphere
- Absolute pressrue
- Atmospheric pressure
- Barometric pressure
15: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- cooling temperature set-point
- adjustment of the spring tension of the TXV
- opening at the pump inlet
- opening at the pump outlet
16: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants
- Nothing must be done
- Place sign, check for leaks, and insulate suction line
17: A thermometer inside a duct measures ____ heat.
- latent
- specific
- hidden
- sensible
18: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
19: The main purpose of the accumulator is to
- prevent liquid slugs at the compressor
- store liquid refrigerant
- provide space for the accumulation of oil and containminants
- provide space for vapor to accumulate
20: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
21: A solder joint melts at temperatures of
- 1,200F to 1,500F
- less than 400F
- 400F to 800F
- 600F to 900F
22: What is the maximum voltage range allowed on an electrical circuit?
- 20%
- 5%
- 10%
- 15%
23: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 18
- 22
- 50
- 33
24: Increasing superheat will do what to your frost line?
- Decrease
- Increasae
- Could either increase or decrease depending on the load conditions
- Nothing
25: If a purge unit fails on a low pressure chiller, what are the symptoms?
- high head pressure
- increased capacity
- low suction pressure
- low pressure chillers do not have purge units