If the R410A compound gauge reads 124 psig, and the suction line temperature at the condensing unit is 54 degrees F, what is the operating system superheat?

To determine the operating system superheat, you need to understand the relationship between the gauge pressure, the saturation temperature corresponding to that pressure, and the actual suction line temperature.

For R410A, a gauge pressure of 124 psig correlates to a saturation temperature around 54 degrees F. Superheat is defined as the difference between the actual suction line temperature and the saturation temperature at the measured pressure.

In this scenario, since the saturation temperature at 124 psig is approximately 54 degrees F, if the suction line temperature is also 54 degrees F, then the superheat calculation would show that there is no difference between the suction line temperature and the saturation temperature, indicating a superheat of 0 degrees F.

However, it's important to analyze the choices based on the correct calculations. If the temperature were instead at a higher value, for instance, if the actual suction line temperature were higher than 54 degrees F, you would calculate the superheat by subtracting the saturation temperature from the actual suction line temperature. Since the question assumes that the saturation temperature is at the same point as the suction line temperature (both at 54 degrees), if the real scenario considers some typical deviations, it may allow for readings that increment the perceived readings