Question: The second best way to charge a capillary tube system is to?
Answer: Use the superheat charging table or curve.
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Question: A temperature differential across a filter dryer indicates?
Answer: A restricted filter dryer.
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Question: The greatest need for subcooling the refrigerant is to?
Answer: Prevent liquid line flash therefore making the system more efficient.
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Question: The External equalizing tube on the TXV is used on?
Answer: Long evaporators having significant pressure drops.
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Question: The most accurate method of charging a capillary tube system is to?
Answer: Weigh the charge into an empty system.
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Question: The greatest advantage of a TXV over a cap tube or fixed bore metering device is the?
Answer: TXV can adapt to load very quickly.
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Question: In an operating system, you should have liquid and vapor in the?
Answer: Evaporator and condenser
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Question: The refrigerant charge in a TXV remote bulb or power element must be?
Answer: Identical to the refrigerant in the system.
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Question: An accumulator is used to?
Answer: Prevent liquid refrigerant from reaching the compressor.
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Question: The basic components of a refrigeration system are?
Answer: Compressor, discharge line, condenser, metering device, receiver, evaporator & suction line.
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Question: When using a charging chart on most fixed orifice type central air conditioning systems, the following temperatures and conditions must be known?
Answer: Indoor wet and dry bulb, outdoor dry bulb (ambient), and superheat.
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Question: The initial refrigerant charge into an evacuated system should be made?
Answer: With a small amount of vapor first, followed by liquid into the high side.
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Question: A liquid receiver is used to?
Answer: Store liquid refrigerant.
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Question: At higher loads, a sight glass located in the liquid line of a refrigeration system will?
Answer: Bubble if the system is undercharged.
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Question: _______ can be used for leak detection with all high pressure refrigerants.
Answer: Electronic halogen leak detectors
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Question: The pressure at which refrigerant changes state, from a vapor to a liquid is the?
Answer: Condensing pressure
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Question: A rise in evaporator pressure causes the AXV to begin to?
Answer: Close
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Question: High and low pressures in a refrigeration system are seperated by the?
Answer: Metering device and compressor
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Question: The component in a refrigeration system used to catch and prevent liquid from entering the compressor is the?
Answer: Accumulator
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Question: In the evaporator?
Answer: Heat is transferred from the refrigerated space to the refrigerant.
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Question: Superheat supression is the process of?
Answer: Injecting liquid refrigerant into the discharge line.
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Question: Subcooling always refers to?
Answer: A liquid cooled below its saturation point
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Question: A pressure guage placed anywhere from the metering device to the compressor will read?
Answer: The low side evaporator pressure
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Question: The compressor superheat should always be?
Answer: Between 20 to 30 degrees
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Question: The TXV's operation uses which of the following pressures?
Answer: Remote bulb, spring & evaporator
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Question: The refrigerant passing through the filter drier on the high side of the system should be in what state?
Answer: liquid
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Question: A sight glass would normally be located?
Answer: In the liquid line, before the metering device
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Question: The term, Refrigerant "Conditions" refer which of the following?
Answer: Saturated, superheated, or subcooled refrigerant
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Question: A TEV sensing bulb which becomes detached from the suction will cause these symptoms?
Answer: Low suction pressure and lower than normal discharge pressure
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Question: Subcooling can be defined as?
Answer: Any sensible heat taken away from 100% saturated liquid
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Question: The remote bulb of a TXV shoud be fastened to the?
Answer: Outlet of the evaporator on the suction line
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Question: The heat energy that causes a liquid refrigerant to change to a vapor at a constant saturation temperature for a given pressure is referred to as?
Answer: Latent heat
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Question: The purpose for a Liquid Amplification LPA is to?
Answer: Help prevent flashing and increase subcooling
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Question: In the first few passes of the condenser?
Answer: The refrigerant should be de-superheated
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Question: Always charge a TXV, receiver, sight glass system under a?
Answer: High load condition
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Question: A balanced port TXV?
Answer: Has a needle valve that cancels out the effects of the liquid pressure
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Question: One of the main functions of a condenser is to?
Answer: Superheat the liquid
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Question: A liquid- to-suction heat exchanger is often used to?
Answer: Increase liquid subcooling
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Question: Most modern refrigerants exist in the?
Answer: saturated vapor state and saturated liquid state
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Question: A solenoid valve in a pump down system?
Answer: Its located before the metering device
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Question: An automatic expansion valve (AXV) is best suited?
Answer: When the system load remains fairly constant
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Question: The temperature/pressure chart is only good when the refrigerant is in the?
Answer: Vapor and liquid mixed
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Question: An air conditioning or heat pump system must have?
Answer: 400 - 450 cubic feet per minute (cfm) of air across the evaporator
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Question: A partially clogged cap tube can cause?
Answer: A starved evaporator
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Question: When charging air conditioning systems with a capilary tube or fixed orifice metering device, the technician should?
Answer: Consult the manufactures specs and use their exact method
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Question: The refrigerant charge on a capillary tube system is?
Answer: Very critical on all units
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Question: An overcharge of refrigerant will result in?
Answer: Elevated head and suction pressures
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Question: The evaporator temperature on an air conditioning system should be?
Answer: 40 to 50 degrees
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Question: The factory superheat settings for TXV's used with central air conditioning systems should be?
Answer: About 10 degrees
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Question: Superheat always refers to?
Answer: A vapor refrigerant
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