I may have to split this motor information off to a different thread, but here is some more info about the 260m's motor/s.
The original that came with my boiler:
Dayton, 6k122k, 1/2 hp 115/230v 1ph. 9.2amp, SF 1.15 1725rpm cont. duty cycle. standard duty.
The 'farm duty' motor I'm buying on Monday. BTW, the reason the price is low, is it is a discontinued Dayton product.
Dayton, 6k592, 1/2 hp 115/230v 1ph, 9.2 amp SF 1.15. 1725rpm cont. duty cycle. 'Farm duty'
The 'light duty' but high effeciency donated motor:
Dayton 1k079BA, 1/2 hp 115/230 1 ph 8.0amp SF1.25. 1725rpm.. 'this is a specialty duty motor'
What I've learned: There are NO GRAPHS of start torque, hp at rpm, running torque etc. Even finding what the h#LL 'farm duty meant was a struggle. The motor industry apparently lives on 'old knowledge' and word-of-mouth. Just as an asside:, the water pump industry has graphs galore of flow vs. head pressure, amp use etc. All available online.
The two 6K Dayton motors are 7" diameter, cap start motors, The 'specialty duty' motor is only 5" diameter, cap start. The capacitor is much bigger, 450-550uf vs 330-380uf on the larger motors. The larger diameter motor and armature provide a LOT more torque, at the expense of a higher amp load under continous duty.
So it appears that the smaller specialty motor is a low torque, large capacitor-start motor that is not capable of pulling the start torque needed to get the fan and auger turning on the AA boiler. However once running it would have used less electricity. But since the AA boiler starts and stops several times an hour, I need a strong starting motor.
This morning the motor is much quieter, the bearings seem to have 'run in' a bit. I removed the belts and gave it a hand spin and a test run, the motor is sounding much better than last night.