Topics: All categories in the pool
1: The two basic types of evaporators are
- direct expansion and plate
- prime surface and finned
- flooded and direct expansion
- finned and plate
2: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.
- 50
- 100
- 550
- 350
3: The location of the thermal bulb for the TXV on the evaporator effects
- both the pressure and temperature in the feeler bulb
- the amount of superheat required to operate the TXV
- the amount of liquid in the evaporator
- the amount of gas in the evaporator
4: Refrigerants shall be classified by
- toxicity and flammability
- requirements for commercial, industrial, and residential occupancies
- color codes
- maximum permissible quantities of each group
5: The actual expansion curve of compressor follows most nearly which one of the following
- Volume
- Adiabatic
- Pressure-Temperature
- Isothermal
6: A start capacitor is wired in _____ with the start windings.
- junction
- series-parallel
- parallel
- series
7: In a horizontal shell & tube condenser, the ammonia is liquefied by
- removing the latent heat of fusion
- passing thru the tubes from top to bottom
- removing the latent heat of vaporization
- water sprayed over condenser
8: 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)?
- centrifugal switch
- duel-voltage switch
- printed circuit board (PCB)
- motor starter
9: _____ and its alloys are suitable for use with ammonia systems.
- Magnesium
- Copper
- Zinc
- Aluminum
10: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Non-positive displacement
- Positive displacement
- Low Pressure displacement
- Pressure induced displacement.
11: Large mercantile occupancy is
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
12: 1 HP = ____ Watts?
- 3,412
- 11,239
- 3.1416
- 746
13: Low ambient controls are used when
- always
- when systems run all year round
- economizers are used
- on air conditioning systems only
14: "E" represents _____ in the Watt's law formula.
- amperage
- reactance
- watts
- voltage
15: Relief valves are rated in
- gallons of water per minute
- pounds of air per hour
- pounds of air per minute
- gallons of water per hour
16: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
- 2F difference
- far apart or greater difference
- nearly the same
- a ling psychrometer doesn't have two theremometers.
17: The reversing valve is commonly used
- when the code requires a check valve
- on commercial system that involve two different temperatures
- on all heat pumps
- on multiple compressor systems
18: What is a high-side float?
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
19: A pressure relief should be located at least _______ from windows and doors.
- 25'
- 15'
- 30'
- 20'
20: Mercury was used in thermometers primarily because it
- never freezes
- vaporizes at very high temperatures
- was inexpensive
- expands uniformly
21: Ammonia systems use ____ pressure to adjust oil pressure
- air
- stream
- liquid
- discharge
22: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
23: What is R-22?
- Chlorodifluoromethane
- HFC
- CCFCM
- Chlorofluoromethane
24: When an inspection is needed, how often must it be done?
- every 18 months
- every 24 months
- annually
- every 36 months
25: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above