My EMT 927A motor still using an original 3uf Frako capacitor (look like paper in oil type capacitor). Motor is running smoothly with a little vibration if I touch the motor with my fingers.
1. Does Frako paper in oil capacitor change capacitance after more than 60 years? Do this type capacitor typically reduce or increase in capacitance?
2. Do I simply add small value capacitors (0.1uf, 0.22uf, 0.33uf etc) to the existing Frako 3uf so I can further reduce the light vibration?
3. Is there a more accurate way to measure the reduction of motor vibration ( instead of touch the motor)?
Indeed this capacitor change value over time best to replace this with a modern motor run capacitor , the value is critical but the same holds
for the variable serie resistor.
The intension is to equalize the voltage across the three coils , its a three phase motor.
I use a accellerometer and a FFT analyser for that this is the most accurate methode .
