Mark Lloyd writes:

Lowe's claims to have a 3HP electric chain saw, that still works on a
15A receptacle.

Assuming it's not simply a baldfaced lie, that is an intermittent
rating. As in "if you load this motor with a brake to the point where
it produces maximum output in overload, it's producing 3 HP - until the
circuit breaker trips or the motor burns up, whichever comes first".

The rating might actually make a bit of sense for a chainsaw, where
hitting a hard spot *will* cause the motor to put out more power
temporarily, and where you're comparing against gas-powered motors where
the HP rating is the maximum HP available.

But it's not comparable to induction motor ratings, where "1 HP" generally
means it will deliver 1 HP all day, and nearly 2 HP momentarily when
overloaded.

Rating continuous-running things like shop vacs and air compressors in
"peak HP" is completely bogus, of course.

Dave