I have an old Clarke motor (1/5 HP, 0.15 KW, 240 v, 1.8 A, 1400 rpm, type 5DB, single phase according to the rating plate,) that only runs at
400 rpm whether loaded or unloaded. I am looking for suggestions for why it is slow, and how I can rectify the fault.My inspection of the motor reveals that: [1] It has no brushes so I guess it is an induction motor. [2] It has a 8 microFarad external capacitor which suggests it is a run capacitor not a start capacitor from what I have gleaned from the internet. [3] The bearings are not binding or rough, and the spindle is free to turn. [4] A cheap multimeter test of the disconnected capacitor gives a gradually increasing resistance up to 20 ohms. [5] A cheap multimeter test of the windings from the capacitor terminals reads 58 ohms.
Any clues folks?