Re: 1.0 HP electric pool pump motor uses 1,500 watts per hou
I would agree that for residential pool pumps, the motor's nameplate HP has very little meaning by itself. However, it is still important rating for an induction motor in an industrial application with varying loads. This is where the practice of using the label HP for nominal load and the service factor for peak load originated. I think motor manufactures are just trying to be consistent in their rating system and nomenclature for all motors in all applications including pool pump motors.
However, it was the pool pump manufacture who made the decision to offer two identical pumps with two different motor label ratings (up rated and full rated). This was unnecessary and just added to the pool owners confusion.
Unfortunately, many pool owners attempt to draw conclusions about a pump's size and/or power from the motor's label HP or even the SFHP. At best, there is only a loose correlation. But to truly understand the characteristics of a pump, one should ignore the motor label and focus on the pump's head curve. That is the only way to compare pump performance.