440.32 requires that the conductors be rated for 125% of the branch circuit selection current or the rated-load current of the motor/compressor.
Your example: 125% of 16 amps equals 20 amps. I would run #12 copper.
Voltage drop? No, that is the range of the voltages the motor will run at. These voltages are "nominal". The actual measured voltages will vary from these slightly. Yes this motor will operate at any voltage between these two. Motors will draw more amperage at lower voltages, but keep it within reason.
The NEC suggests we limit the voltage drop to 3% from the nameplate voltage for reasonable efficiency of operation. Some motors and some motor applications could handle a VD of 10%. As the voltage falls, the motor will heat up more and more. It is a trade off, early motor failure or full voltages. Which is more expensive?
Earl
