In the first of a pair of articles on motor fundamentals for HVACR, the author gets into everything from industry standards and service conditions to changing speeds, enclosures, and the often misunderstood service factor. You’ll want to save this one for your team’s reference library.
Our objective in specifying motors for HVACR equipment is to start and run the driven equipment under all operating conditions reliably and with reasonable life expectancy. The manufacturer of the equipment and motor supplier have primary responsibility for this, but we should understand motor ratings, design features, and application conditions well enough to identify project-specific conditions that affect motor selection and include them in the equipment schedule or motor specification. This article is the first of two on the subject that aim to take you beyond the basics of voltage, speed, and horsepower and help you address other important considerations in your specification.