I am reverse engineering a multi-speed blower controller and perplexed by my results. The blower (230V single phase 250W rated) is the heart of range hood. The schematic on the controller end is clear (left side below) but the motor unit itself (right side) is beyond reach for dismantling.
I measured the resistance between RED (common) and all the other wires. These resistances are listed next to the colors.
It seems to me it's a 4-speed motor with Blue-White-Orange-Black tapping into the primary winding to provide different speeds. Put the speed assumptions next to the resistances.
The capacitor is a "6.3uF 1.27.6CC2 MKP 420V 470V AV ARCOTRONICS" rated for 10k hours and is not at the motor, it's at the controller PCB
It looks like a run cap, it's sized like a run cap (though small for 250W I think?)
I also measured different wire pairs using a LCR meter and did not find any additional capacitance with those measurements
The switches in the circuit diagram are relays driven by a PIC microcontroller, nyt physical switches.
And to the question.. Why is the 6uF cap in the circuit only at the slowest speed (blue wire energized to drive the full winding). Is it even a run cap? And does my guesstimate of the blower internals make sense? I have zero experience with AC motors...