Topics: All categories in the pool
1: 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
2: Setting a pressure relief device shall not exceed ___ of the design pressure
- 75%
- 80%
- 90%
- 100%
3: High pressure controls should be set no higher than
- 80% of set point
- 90% of set point
- 25% of set point
- 10% of set point
4: A positive displacement compressor is
- is a reciprocating type compressor with 2 or more pistons
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
5: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
6: What is an egress?
- An escape route
- A code violation
- A valve put on the low side of the system to prevent frosting
- An entrance or exit
7: What must be done to refrigerant pipes before being buried ?(8.10.4)
- Classifed
- Insulated and installed in a pipe duct (Encased)
- Leak checked
- Certified
8: What would be the classification of a church?
- Large mercantile
- Place of assembly
- Institutional
- Industrial
9: Horizontal piping should be run level.
- False
- No, unless the supervisor on the job says so.
- Yes, if the condenser is located above the evaporator
- True
10: Which has more turns in the windings: Start windings or Run windings?
- Start windings
- Run windings
- They both have the exact same turns
- Depends on the system and capacitor used
11: The density of a gas refers to
- cubic feet per pound
- pounds per square foot
- pounds per cubic foot
- pounds per absolute pressure
12: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- low pressure
- critical pressure
- high pressure
- design pressure
13: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Magnesium
- Nickel
- Zinc
- Copper
14: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
- 30 days
- 2 months
- 14 days
- 1 week
15: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
16: Emergency shutdown procedures, including precautions to be observed in case of a breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a conspicuous card located as near as possible to the
- compressor
- boiler
- outside the machinery room
- evaporator
17: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 75
- 100
- 24
- 50
18: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UV or UR
- UM or UL
- UL and UR
- UL and UM
19: 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
20: 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
21: A start capacitor is wired in _____ with the start windings.
- series-parallel
- junction
- parallel
- series
22: R-12 is
- dichlorofluoromethane
- trichlorofluoromethane
- dichloromethane
- dichlorodifluoromethane
23: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- opening at the pump outlet
- opening at the pump inlet
- cooling temperature set-point
- adjustment of the spring tension of the TXV
24: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
25: Booster compressors connect to the ____ side of the compressor
- oil side
- low side
- vapor
- liquid