Practice Test Geeks(RSES) Refrigeration Service Engineers Society Certification Practice Test
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Refrigeration Fundamentals & System Components Flashcards

7 cards from real RSES practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. The refrigerating effect of a system is defined as:

    Answer: Heat absorbed per pound of refrigerant in the evaporator

    Refrigerating effect (RE) = h_evaporator_out - h_evaporator_in, representing the heat absorbed by the refrigerant per unit mass in the evaporator.

  2. Which component in a refrigeration system is responsible for changing high-pressure liquid refrigerant to a low-pressure liquid/vapor mixture?

    Answer: Metering device (expansion valve or orifice)

    The metering device (TXV, fixed orifice, or capillary tube) creates a pressure drop that flashes some liquid to vapor, lowering refrigerant temperature.

  3. When checking system superheat at the evaporator outlet, a technician finds it is much higher than the TXV setpoint. The most likely cause is:

    Answer: TXV restricted or underfeeding the evaporator

    A restricted or underfeeding TXV allows less refrigerant into the evaporator, causing the refrigerant to become highly superheated before leaving the coil.

  4. In a two-stage refrigeration system, the economizer (intercooler) is used to:

    Answer: Cool the discharge gas from the low-stage compressor and subcool liquid before the low-side expansion device

    The intercooler cools the low-stage discharge gas (reducing high-stage work) and subcools liquid refrigerant, improving overall system efficiency.

  5. The purpose of a liquid line solenoid valve in a refrigeration system is to:

    Answer: Stop refrigerant flow to the evaporator when the system is off or on demand

    A liquid line solenoid valve is an electrically operated on/off valve that stops refrigerant flow to prevent evaporator flooding or pump-down the system.

  6. Which refrigerant blend is classified as 'zeotropic' and exhibits temperature glide during phase change?

    Answer: R-407C

    R-407C is a zeotropic HFC blend whose components boil at different temperatures, resulting in a temperature glide (change in temperature during evaporation or condensation).

  7. A high-pressure cut-out (HPCO) safety control in a refrigeration system is set to:

    Answer: Shut down the compressor if discharge pressure exceeds a safe maximum

    The HPCO stops the compressor when discharge pressure exceeds its setpoint to protect the system from dangerously high pressures.