Figure 2. A simple sine wave with a period of 360° and an amplitude of 1. In single phase power the x-intercepts are 180° from each other. A full period is 360°. A single phase motor has a crest approximately every 16.5 milliseconds giving the motors a tendency to vibrate more, which may contribute to a shortened bearing life.
Bowl wear ring
Machinist at Nickerson Company running a state-of-the-art CNC machine.
Frame-mount Centrifugal Pumps
Utah Lake Cascade Pump
Impeller wear ring
Close-Coupled Vertical Turbine
80 Series® Engine Driven
Model 342A Single Stage End Suction
SF Series®
Figure 3. Three phase power has three identical sine waves overlapping at an offset of 2π/3 radians or 120°. When one phase reaches an x-intercept or node the next phase is only 30° and approximately 5.6 milliseconds from reaching its crest.
Impeller wear ring
Vertical Turbine Pumps, Deep Well
Parley’s Water Treatment Plant. Photo credit SLCdocs.com
Vertical Lathe
“NSF/ANSI 61.” NSF RSS. The Public Health and Safety Organization, n.d. Web. 07 June 2017.