Topics: All categories in the pool
1: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
2: By using nitrogen within a pipe during brazing operation,
- The explosion hazard is confined
- Copper oxide formation is prevented
- Discoloration is prevented
- Exterior scale formation is minimized
3: A device used to measure small pressure differences is the
- phsycometirc
- manometer
- anemometer
- pyrometer
4: What device should be used on low-temperature freezers?
- high capacity TXV
- discharge muffler
- oil separator
- hot-gas by-pass
5: The difference between saturated liquid and saturated vapor is
- heat
- pressure
- volume
- temperature
6: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
7: What is a high-side float?
- 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, 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
- 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
- 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
8: What must be done to refrigerant pipes before being buried ?(8.10.4)
- Leak checked
- Insulated and installed in a pipe duct (Encased)
- Certified
- Classifed
9: How are safety controls wired in a circuit?
- Either series or parallel
- Series
- Series/parallel
- Parallel
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 cheap
- Because it's a non-flammable refrigerant
- Because it's water
11: A capacitor in series with the start windings will do what?
- Decrease the RLA to within 10% of its rating
- Increase starting torque
- Increase run efficiency by 10% of its rating
- Nothing
12: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 10
- 18
- 15
- 24
13: The evaporator is a device to
- Keep the compressor busy
- store liquid refrigerant
- remove heat from the refrigeration system
- absorb heat into the refrigeration system
14: What refrigerant doesn't have to be classifted?
- R-134a
- R-711
- R-718
- R-717
15: The leaving chilled water set point for comfort cooling is typically?
- 66
- 38
- 60
- 45
16: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 75%
- 80%
- 90%
- 100%
17: In an electrical circuit, what is potential measured in?
- Herys
- Amps
- Ohms
- Volts
18: Which of the following is an example of an azeotropic refrigerant?
- R-500
- R-410A
- R-134A
- R-404A
19: 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
20: With a 5/8" X 5/8" x 3/4" tee, what size is the center connection?
- 1/2"
- 3/8"
- 3/4"
- 5/8"
21: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- R-718
- methyl chloride
- ammonia
- trichlorotrifluoromethane
22: Sensible heat is the heat added to a substance to
- raise its temperature
- freeze it
- cause evaporation
- change its state
23: Which oil is hydoscopic?
- mineral
- polyolester
- animal
- SW30
24: On a TXV, the purpose of an external equalizer is to?
- allow a greater adjustment spam
- compensate for a pressure drop across the evaporator coil
- Increase the pressure on the top of the power head diaphragm
- balance the evaporator load
25: NH3 is
- ammonia
- R-508A
- R-718
- lithium bromide