Topics: All categories in the pool
1: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 255 psig
- 365 psig
- 125 psig
- 327 psig
2: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
3: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices or fusible plugs
- shall use fusible plugs
- shall use rupture discs or duel pressure relief valves
- shall use pressure relief devices
4: Halogen refrigerants are corrosive to which type of metal?
- stainless steel
- black iron
- magnesium
- copper
5: What refrigerant is an inorganic compound?
- R-22
- R-132A
- Ammonia
- R-410A
6: Which of the following is not an air velocity meter?
- Anemometer
- Anemotherm
- Velometer
- Hydrometer
7: R-12 is
- dichlorofluoromethane
- dichloromethane
- trichlorofluoromethane
- dichlorodifluoromethane
8: The difference between saturated liquid and saturated vapor is
- volume
- pressure
- heat
- temperature
9: What is not a requirement of a Class T machine room?
- Automatic ventilation
- Tight fitting doors
- Self-closing doors
- Fire hose connected to the building fire protection system.
10: When is the only time you can leave a service container attached to a system?
- Leaking system
- Recovery
- Charging
- Both b and c
11: When using nitrogen for brazing, the pressure should be:
- Very low
- 50-100 psig
- Slightly below atmospheric
- 125 psig
12: Pressure relief valves shall be marked with the data from
- Section VIII Division of the ASME Boiler & Pressure Code
- Section XIII Division of the ASME Boiler & Pressure Code
- Section I Division VIII of ASME Boiler & Pressure Code
- Section IV Division of the ASME Boiler & Pressure Code
13: Low pressure systems have what kind of compressor?
- Rotary
- Reciprocating
- Centrifugal
- Scroll
14: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- oil in evaporator
- moisture in the system
- low head pressure
- not enough oil in the system
15: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Decrease
- Nothing
- Increasae
16: Crankcase heaters are energized
- while the compressor is running
- to allow easy compressor start-up
- to prevent compressor freeze-up
- when the compressor is off
17: What measures gas pressure?
- Manometer
- Hydrometer
- Hygrometer
- Barometer
18: If the spring is adjusted to increase the superheat, this new setting will
- allow more liquid into the evaporator
- shorten the frost line
- lengthen the frost line
- have no effect on the frost line
19: A normal operating evaporator temperature of R-22 for air conditioning is typically
- 32F
- 45F
- 58F
- 55F
20: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 50
- 18
- 33
- 22
21: A single pole-double throw switch uses how many wires?(excluding the ground)
- 5
- 4
- 3
- 2
22: Ashrae states that the equipment on a building needs to conform to adjacent buildings classifications when within ____ feet from opening and intakes.
- 50
- 20
- 15
- 75
23: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
24: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
25: How are a compressor and condenser fan wired?
- series-parallel
- parallel
- series
- parallel-series