How do engineers calculate power factor on a ckt before anything is hooked up? Are motors all similar 80 percent-ish and they just estimate, or can they calculate it exactly.
The power company wants load calcs including power factor. Thanks, Ben

On motors look on the talley plate.

so if the nameplate says 1hp, and it says 7 amps at 120V, then 746/840= 89 percent power factor?