The phase angle of induction motors changes with varying load.
The current draw only changes a little with loads from zero
to the motor's rating. So, if the motor is rated
at 1/2 Hp, 208 V, the running current at rated load
will be something just over 2 A.
I = (745 W * 1/2 * 1.2 (efficiency))/208
At idle, the current may be 1.5 - 1.7 A with a very low power
factor (phase angle near 90 degrees lagging). At full load,
the current will be about 2.1 A with a phase angle of maybe
5 - 10 degrees. This, the motor draws more REAL POWER at
full load, but the current doesn't change much throughout the
range the motor is rated for. This is why external fusing
for motors is to protect the building wiring from fire, it
does not protect the motor from minor overload or overheating.
Internal thermal protectors actually measure the temperature
INSIDE the motor, and thus are a lot more effective.
Jon