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Refrigeration Principles — Texas ACR A Practice Questions

12 questions · 5% of the Texas ACR A exam

Worked questions

1. A filter-drier maintenance procedure calls for replacement when the moisture indicator remains wet after the specified stabilization period. That period has elapsed and the indicator is still wet. What action follows the stated procedure?

  • AWait for an arbitrary yearly anniversary regardless of the indicator.
  • Investigate the moisture source and replace the filter-drier as specified.
  • CTreat the wet indication as proof the system is dry.
  • DRemove the filter-drier permanently.

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why B is correct

The scenario supplies the replacement trigger. Apply it and address the source of moisture; elapsed calendar time alone is not the stated criterion.

2. A walk-in cooler holds time/temperature control for safety food under 2022 FDA Food Code 3-501.16(A)(2). Excluding the section's exceptions, what maximum temperature applies to the food?

  • A32°F
  • 41°F
  • C45°F
  • D50°F

Where to look it up

https://www.fda.gov/media/164194/download

Why B is correct

The specified cold-holding maximum for the food is 41°F. This does not prescribe one thermostat setting for every cooler. Loading, door openings and equipment performance affect the setting needed to maintain food temperature.

3. EPA lists a global warming potential of 3,922 for R-404A. What does this imply when comparing equal masses using that GWP metric?

  • AR-404A has no warming effect.
  • BR-404A can always be released without consequence.
  • R-404A has substantially greater warming potential than the same mass of CO2.
  • DThe value proves R-404A is suitable for every refrigeration system.

Where to look it up

https://www.epa.gov/hfcs/technology-transitions-gwp-reference-table

Why C is correct

A GWP of 3,922 indicates a warming impact substantially greater than the CO2 reference for equal mass over the metric's time horizon. It is not an equipment-selection approval and says nothing by itself about toxicity or installation compatibility.

4. A leak-test exercise provides a calibrated electronic detector approved for the system refrigerant. A repeatable signal occurs at one joint after background checks. What does this support?

  • AProof that every other joint is leak-free.
  • BPermission to vent the entire charge.
  • Further confirmation and repair planning at that suspected leak location.
  • DA universal rule that all refrigerants require this detector.

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

The localized repeatable signal identifies a suspected location under the stated test conditions. It neither certifies the whole system nor establishes a universal leak-test method.

5. An evacuation procedure specifies an absolute pressure of 500 microns or lower and a rise of no more than 100 microns during its stated isolated hold test. A system starts at 400 microns and rises to 650. Which conclusion follows?

  • AIt passes because the initial reading was below 500 microns.
  • BIt passes because 650 is a smaller vacuum than atmospheric pressure.
  • It fails the specified pressure-rise check.
  • DThe rise is only 50 microns.

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

The rise is 650 − 400 = 250 microns, exceeding the specified 100-micron allowance. Investigate the failed test; do not confuse absolute microns with an unspecified inches-of-mercury gauge reading.

6. An air-cooled refrigeration unit has adequate electrical supply and maintenance access, but nearby shelving blocks its condenser airflow. Which installation issue directly needs correction?

  • APower source availability
  • BSpace for maintenance access
  • Ventilation requirements
  • DColor matching with the store's decor

Where to look it up

https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.303

Why C is correct

The blocked condenser airflow is the stated defect and must be corrected to permit heat rejection according to the equipment instructions. Electrical supply and maintenance access remain important; the question expressly states they are already adequate.

7. During a controlled refrigeration pressure test, pressure falls after temperature effects have been accounted for. No leak location has yet been identified. What is the next diagnostic task?

  • ADeclare that the compressor is certainly the leak source.
  • BDeclare every joint sound because none is visibly wet.
  • Use an appropriate leak-location method on the circuit.
  • DChoose a leak detector solely by a universal sensitivity ranking.

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

The test indicates a loss that requires localization. It does not locate the fault or establish one detector technology as best for every refrigerant and environment.

8. A retrofit specification permits only refrigerant X with a listed compressor/oil combination. A proposal substitutes refrigerant Y without compatibility data. What should the reviewer do?

  • AAccept Y solely because its boiling point is lower.
  • BMix X and Y to average their properties.
  • Require documented compatibility and approval before accepting the substitution.
  • DAssume every low-temperature refrigerant is interchangeable.

Where to look it up

Explicit exercise assumptions; not a universal code requirement.

Why C is correct

The scenario gives a specific approved combination. Refrigerant selection must respect that constraint; a temperature alone does not authorize a substitute or mixture.

4 more in the bank

Answers and explanations for these are in the app.

  • A residential refrigerator has a refrigerant charge of 3.5 pounds. What is the minimum refrigerant charge required for a similar refrigerator according to the 2024 UMC?
  • A warehouse refrigeration system has a refrigerant charge of 1500 lbs. What is the minimum refrigerant charge required for this system according to the 2024 IMC?
  • What is the recommended airflow velocity for a supply air duct in a commercial air conditioning system according to the 2024 IFGC?
  • Which of the following factors contributes most to the efficiency of a refrigeration system?

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