Vacuum cleaner series universal motor triac control board

[FusionJim]

Long story short, I got a vacuum cleaner with a standard universal series motor inside. It also had the TRIAC pcb with a potentiometer and a triac/thyristor to control the RPM which allowed to control the suction power. Some moisture got on the pcb and it shorted. I simply took it out since I run the cleaner at max setting anyway thinking that at max setting the motor receives the mains voltage anyway. I think I was wrong because now the motor tends to overheat shortly after running. Can anyone explain how the triac board controls the universal series motor? Because judging from sound alone, the motor spins at roughly the same RPM as before yet now it overheats quickly. How do these board alter the sine wave applied to the motor to keep it cool yet running fast?

 

[Guineafowl]

They chop out varying amounts of the leading edge of the sine wave. Perhaps your speed controller/motor combo was never designed to pass full power, or there’s a separate fault in the motor. Have you tried troubleshooting the PCB? They’re pretty simple. Some makes, like my Henry, will supply replacement controllers.

 

[Baluncore]

I simply took it out since I run the cleaner at max setting anyway thinking that at max setting the motor receives the mains voltage anyway.

What is your local AC supply voltage ?

Can you switch the unit between 120Vac and 240Vac ?

 

[FusionJim]

@ Guineafowl I found a replacement controller, and a different motor that has roughly the same size. now it works it seems. This motor that I had previously, I believe the windings either in stator or rotor armature had shorted because even with the new added controller it still heated up fast, the RPM were fluctuating and it started to smell like windings when they get too hot.
Either the windings got some mechanical damage when I was moving the motor, or more likely running the motor without the control board caused it to overheat and a fault in insulation formed. There aren't many other options in a simple system like this.

@Baluncore, the motors are all 230 VAC (more precisely 220-240 VAC) rated. The vacuum never had any switch it was made to run on 230. My mains voltage is 230 VAC, was 220 earlier but now we have 230