Due to having found a 7.5 HP single phase motor, I swapped the three phase motor on my compressor for a single phase Marathon motor:
formatting link
What surprised me was that this 7.5 HP motor has insulation class F and, apparently, it would be normal to see a rise in temperature to
311 degrees F during continuous operation, at maximum ambient temperature of 105 degrees F. We rarely get 105 degrees around here, but 100 is normal for a summer, so the motor can get to way above the water's boiling temperature.
This seems hazardous to me, personally.
I did verify that the amp draw of this motor, with the compressor close to full pressure of 140 PSI, is about 30 amp, so the motor is functioning within its 30 amp nameplate amp draw. i