Thread: Real Power Ratings of Machinery

Paul, with induction motors from respectable manufacturers, the rated power is output power.

If I go and buy a 1hp single pahse motor, and also buy a 3 phase 1hp motor (either Hitachi or Toshiba around here), I could put money on the fact that they will produce the same output power. Difference being the 3 phase will do it easier, quieter and using less (only a tad) input power.

For universal motors, the rated power can be the output, but not always since most cheapie things use brushed motors.

Generally speaking, you cannot estimate the output power based upon what it feels like. Just doesn't work like that.

That big induction motor I mentioned, I bought it to replace the universal motor that runs my bandsaw that has sparking brushes. I don't know for certain that the induction motor will do the job, since the brushed motor bogs down and finds some more grunt to keep on going. I don't know that the induction motor will do that without getting pretty upset. So I live with the sparks.

The only true way to find out what motor does what is to hook it up to a dyno, and that's not really worth the money or hassle to do so.