I have a phase regulator and I'm using it for regulating the RPM of a fan - centrifugal blower. The motor is a shaded pole induction motor (220VAC, 28W).
The regulator is working fine, but if the RC Snubber (R8+C8) is disconnected (due to the failure of C8 or R8), the voltage and current are getting out of phase and false triggering / turn off of the triac occurs, which leads very quickly to overheating and failure of the coil of the induction motor.
What type of capacitor should I use to minimize the chance of its failure (I’m using this regulator for 8 hours a day)?
Or is there a way to add additional circuit for protection, if such failure occurs?
I’m currently using Polypropylene capacitor rated for 250VAC/400VDC (Wima MKP 10 - https://www.wima.de/wp-content/uploads/media/e_WIMA_MKP_10.pdf). For the resistor I’m using 1W/Metal Film.