Question 114Refrigeration/AC - Assistant Engineer70% to pass
The coil temperature measured at the expansion valve sensing bulb of an operating system is 10°F. The low side pressure with the compressor running as shown on the gauge illustrated indicates 15 psig. What adjustments or changes, if any, should be made to the system? Illustration GS-RA-16
AI Explanation
The correct answer is D) The expansion valve should not be adjusted, as the degree of superheat is within the accepted range.
The explanation is as follows:
1. Confirm the correct answer: D is the correct answer.
2. Explanation: With a coil temperature of 10°F and a low-side pressure of 15 psig, the degree of superheat at the expansion valve sensing bulb is within the accepted range, typically 6-12°F. This indicates the expansion valve is functioning properly and does not require adjustment.
3. Why other options are incorrect: Changing the filter drier (A), cleaning the evaporator coils (B), or cleaning the liquid line strainer (C) are not necessary based on the given information, as the system appears to be operating within the proper parameters.
4. Concise explanation: The degree of superheat is within the accepted range, so the expansion valve should not be adjusted.
Related Questions
#112 Which of the installation steps listed is necessary for the proper operation of the thermostatic expansion valve? #113 Which of the listed statements describes the method used to determine the amount of superheat present in the suction gas leaving the evaporator coil? Illustration GS-RA-16 #115 Expansion valve maintenance should include which of the following procedures? #116 When replacing a thermostatic expansion valve power element, what is true concerning the thermal bulb? #117 What maintenance may be carried out on a thermostatic expansion valve?