Topics: All categories in the pool
1: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 9F
- 21F
- 11F
- 29F
2: An air conditioning system rated for 36,000 BTU's is equivalent to
- three tons of cooling
- two tons of cooling
- 12,000 tons of cooling
- one ton of cooling
3: When air is ducted through a machine room that services occupied space, What must be done?
- Ducted and sealed
- Welded and seamed.
- Flanged and gasketed
- Insulated and cross broke
4: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- R-718
- ammonia
- trichlorotrifluoromethane
- methyl chloride
5: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
6: What is used to check very low air pressures in air conditioning duct?
- Manometer
- Anemomter
- Barometer
- Vacuum gauge
7: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
- R-22
- R-12
- R-113
- R-11
8: Relief valves are rated in
- gallons of water per hour
- gallons of water per minute
- pounds of air per minute
- pounds of air per hour
9: 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
10: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
- 2 months
- 30 days
- 1 week
- 14 days
11: The critical temperature of a refrigerant gas occurs when
- any decrease in pressure will cause condensation
- any increase in pressure will not liquefy the gas
- the gas is no longer saturated
- the gas returns to a liquid
12: What is the maximum voltage range allowed on an electrical circuit?
- 15%
- 5%
- 10%
- 20%
13: On a pumpdown system, the liquid-line solenoid is controlled by the
- low pressure switch
- thermostat
- low-ambient controller
- defrost timer
14: What pipe can not be used for refrigeration?
- L
- M
- N
- K
15: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- “U” or “UM”
- “UV”
- “UL”
- “UM” and “UV”
16: Brazed joints melt at temperatures above
- 1,200F
- 500F
- 1,000F
- 800F
17: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
- lower
- higher
- the same
- there is no Group B1 refrigerants
18: What is NOT a positive displacement compressor.
- Rotary
- Scroll
- Centrifugal
- Reciprocating
19: RPM's of a centrifugal compressor are at approximately?
- 15,000
- 30,000
- 10,000
- 500
20: What is a high-side float?
- 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
- 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
21: A self contained system
- is a unit system Group II refrigerants only
- is a unit system Group I refrigerants only
- is any system or part of a system used to increase evaporation by expansion or vaporization
- is a complete factory made and tested system
22: pressure relief valves must discharge to the atmosphere at a location not less than 15 feet from ground level and ____ feet from any window, ventilation opening, or exits of buildings.
- 10
- 20
- 15
- 25
23: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- the liquid side of the system
- high side of the system
- the vapor side of the system
- low side of the system
24: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
- 2.5
- 1250
- 2
- There isn't enough information to answer.
25: Floc point testing on refrigeration oils are traditionally tested with a 10% oil and 90% refrigerant mixture.
- True
- False