I gave a Millwright friend of mine an old commercial furnace motor (120v) that he wanted to use for a project.
It is a four-speed motor and if I recall correctly it has seven leads, two for the cap, one for neutral and the four remaining are labeled low, med low, med and high speed.
We bench tested the motor with the intent to use a tachometer to test the rpm at each of the four speeds.
The surprising part of all this is that we got 1200 RPM no matter which lead (low, med low, med or high) was hooked up to the supply.
When we hooked it up for the various speeds we tied one lead to the supply and capped the other three.
Should the three "speed" leads not being used be tied together rather than tied back separately to get the various speeds?
I am pretty sure that when the motor was in service the high-speed lead was used and the other three were tied back separately but my memory isn't what it used to be...
Thanks for any input.
