Commercial Refrigeration Certification Practice Test 2026 - Free Refrigeration Certification Practice Questions and Study Guide

The differential setting of a pressure control is calculated by finding the difference between the cut-in pressure and the cut-out pressure. In this scenario, the cut-in pressure is 40 psig, and the cut-out pressure is 15 psig. To find the differential, you subtract the cut-out pressure from the cut-in pressure:

40 psig (cut-in) - 15 psig (cut-out) = 25 psig.

Therefore, the required differential setting is 25 psig, making it the correct choice. This setting ensures that the refrigeration system operates efficiently by maintaining the proper pressure range for optimal cooling performance.