This newsgroup has been very good with these kind of questions, even
if maybe they'd work better in an HVAC repair group or the homebrewing
newsgroup. I have a grain mill for crushing malt for homebrewing.
The handle method is a pain in the but, and a lot of folks end up
motorizing their mills. In my case, I asked the HVAC folks that had
done a lot of work on my house for an old motor if they come across
one. I've got one here now and I'm trying to make sense of it before
I start trying to hook it up to the mill.

I think they were proud of themselves when they arrived with this
metal enclosure with the motor and everything, which was fine by me.
I had asked for a motor that works at 110V, and that's what they said
they pulled. I did test it with a switch up to wall power, and it
seemed to work--despite tripping the breaker when I turned off the
switch. That was because methinks I botched that wiring.

So it is a 1/2HP, 1020RPM motor. Reading the side here, I see
"V200-230." So is this actually a 220V motor? I'm not so sure because
I see three jumpers labelled A through C:

A: LO
B: MED
C: HI

Which one I pick works in conjunction with the black contact to give
me my line voltage. So does this mean I have some flexibility in
voltage? It was connected to 'A' originally, and I haven't tried
messing with it. If this somehow lets me using 110V, then what effect
will this have on the horsepower and the rpm? I have yellow and black
lines going to a start capacitor rated 20.00/370.

It is a thermally protected motor and there's a note "CONT AIR OVER"
which implies to me it normally would be cooled by the blower fins. I
have to take that thing off to work this thing, so I'm wondering how
long I might reasonably expect to run the motor before it trips the
protection. I'd probably only need to run the motor 5 minutes to
crush my grain, if that helps.