Practice Test Geeks(CRST) Certified Refrigeration Service Technician Practice Test
← All CRST Flashcard Decks

Installation & Maintenance Practices Flashcards

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

Read the first 7 Installation & Maintenance Practices flashcards as text

  1. Which tool is used to measure the depth of a vacuum during system evacuation?

    Answer: Micron gauge (electronic vacuum gauge)

    An electronic micron gauge accurately measures deep vacuums in microns of mercury, which standard manifold gauges cannot resolve.

  2. A walk-in freezer door gasket is worn and not sealing properly. Besides temperature loss, what additional problem can result?

    Answer: Excessive frost buildup on evaporator due to warm, moist air infiltration

    Warm, humid air entering through a faulty door gasket increases the moisture load on the evaporator, causing excessive frost accumulation and longer defrost cycles.

  3. What is the recommended torque method for tightening flare fittings to avoid over-tightening and cracking the flare?

    Answer: Use a calibrated torque wrench to the manufacturer's specification

    Manufacturer torque specifications applied with a calibrated torque wrench prevent both under-tightening (leaks) and over-tightening (cracked flares).

  4. During installation of a refrigeration system, the technician discovers the power supply voltage is 208V but the unit is rated for 230V. What should be done?

    Answer: Install a step-up transformer or notify the customer that voltage must be corrected before startup

    Operating a 230V-rated unit on 208V causes low-voltage conditions that can overheat motors and void the warranty; the supply voltage must be corrected.

  5. What is the function of a liquid line solenoid valve in a refrigeration system?

    Answer: Pump down the evaporator when the system shuts off to prevent liquid migration

    A liquid line solenoid valve closes on shutdown to pump down the low side, preventing liquid refrigerant from migrating to the compressor crankcase.

  6. When pressure-testing a refrigeration system with nitrogen, what is the maximum test pressure typically used for medium-temperature applications?

    Answer: 150 psig

    For medium-temperature systems, nitrogen pressure tests are commonly performed at approximately 150 psig, consistent with low-side design pressure ratings.

  7. A technician is installing a new TXV (thermostatic expansion valve) on a system. Where should the bulb be clamped?

    Answer: On the suction line at the evaporator outlet, in good thermal contact

    The TXV bulb senses suction line temperature at the evaporator outlet to control superheat, and must be clamped in firm thermal contact at that location.