ESCO Air Conditioning Practice Exam

The R-410A compound gauge reads 124 psig in the suction line temperature at the condensing unit is 54°F. What is the operating system superheat?

1. 10°F

2. 12°F

3. 14°F

4. 16°F

The correct answer is: 10°F

The operating system superheat is measured by the difference between the actual suction line temperature and the corresponding saturated temperature of the refrigerant at the suction pressure. In this case, the R-410A compound gauge reads 124 psig and the suction line temperature is 54°F. Using a pressure-temperature chart for R-410A, we can see that the corresponding saturated temperature is around 44°F. This means that the operating system superheat is 54°F - 44°F = 10°F. The other options are incorrect because they do not account for the correct saturated temperature at the given pressure. For example, option B calculates the superheat using a saturated temperature of 54°F, which is incorrect. Similarly, options C and D use saturated temperatures of 64°F and 74°F respectively, which are also incorrect.