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.
Generally, when we think about BAS, it is in the context of large commercial buildings, those well over 25,000 sq ft. According to the latest government data though (from the 2012 Commercial Building Energy Consumption Survey), 88% of all commercial buildings are 25,000 sq ft or less.
Reactors for AC drives are available as either AC reactors or DC reactors (DC link chokes). Both serve the same main purpose: to smooth the current flow to the AC drive, and reduce damaging harmonics produced on the power line.
Why was one floor’s laboratory ventilation failing to keep up, when it was even the closest floor to the rooftop fans? Some system sleuthing led two engineers to a fitting conclusion. Read more stories in May Issue 2017.