Kool-a-matic fan replacement

[mrkane]

(04-05-2014 14:22)davidbrady Wrote:  What kind of speed control do you have on the Kool-o-matic; i.e., potentiometer, rheostat, solid state, none, etc?

I ask because the speed control should drop the voltage going to the motor and the current going into it. My guess is that the Kool-o-matic uses a rheostat. If so then you should check to see if the rheostat offers resistance at the high speed setting. It could be that the rheostat is the current limiting factor in your motor circuit, in other words, choose a multi-position rheostat that limits the max current to your wiring specifications.

Speed control was with wire-wound resistors, but it burned up when the bearings froze. (Max speed was full voltage: ie 1/10 hp * 746 w/hp ~= 7.5 A)

Previous postings stated the NAPA motor burned up the relay due to excessive current. I wouldn't trust the present wiring or thermostat to handle that much power, either.

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M.R.Kane
1987 PT40 'Sleipnir'
currently near Wills Point, TX