In answer to one of your recent questions....circuit breakers are not available (typically) in very small increments. They are used to protect the *wiring* from exceeding its rated values. Since there are very few wire sizes, with some pretty standard current carrying ratings, the breakers for standard panels are to match those circuit values.
Motor protection, on the other hand, is usually accomplished either with fuses (in a fuse block, often in a fused disconnect) for each unit. A given circuit can theoretically serve more than one motor...which is another reason the circuit breakers in a panel are not used to protect the motor. You would then need to size the circuit (and circuit breaker and wire) to serve two motors. By the time one drew enough current to trip the breaker feeding both motors, the motor would be toast....but I digress
The more common means of protecting motors today is with heater-based overload protection. Often this is an item that attaches directly to a magnetic motor starter (self-latching relay). The heaters heat some low-temp alloy that melts and allows a spring loaded mechanism to disconnect the load. The heaters are available in tiny increments so that you can properly protect any motor. The heaters are specific to a given vendor of the motor protector...and often to a given series of that protector. Charts show you which heaters to use with a given current load...for single, three phase, etc.
When these heated protectors do their job, they are resettable by pushing a button that sort of rewinds the spring mechanism...which is then held back in its operating position by the low-temp alloy that has re-hardened.
More than you wanted to know...but lots of folks never see this stuff so thought I ought to describe it so you will know what you are looking for.