wiring for two speed Emerson motor
I have a Surefire 101ce wood/electric furnace that I am currently using exclusively as a forced air electric furnace. It has been functioning perfectly except that the motor would occasionally jump around at startup and the problem was found to be the centrifugal startup switch being loose on the shaft, and it was replaced. However after replacement something is wrong and the motor fails to go into the high speed mode or start up in the high speed mode unless it has no load.
A new motor has been ordered, however I have been told that the wires for the high and low speed windings (both 115V) must not be energized at the same time, yet the schematic for the furnace seems to indicate that this is the case (and the old motor operated happily for 29 years).
The old motor is an Emerson SA55JXFGS-4781 cat. 5793
Can this motor have both windings powered at once for the high speed mode? Does this mean it has internal circuitry to automatically cut off the power to the low speed windings in this case?
Would a replacement motor be okay as a direct replacement, or am I going to have to add additional control relays to the two element sequencers which also turn on the low and then high speed fan motor modes to prevent both windings being energized at once in high speed mode?
Thanks for any information or advice on this motor and furnace problem.