The TRIAC actuator of a DC motor through a bridge rectifier.
I activate a DC motor from the mains through a TRIAC (BTA16) in series with a 10 Ohms resistor for the inrush current limitation, in series with a PTC thermal protection for the motor jamming protection and in series with a bridge rectifier needed to supply the dc motor with dc voltage, filtered by a 100 uF/400 V capacitor.
The TRIAC is triggered by a zero-crossing optotriac (MOC3043). The TRIAC is provided with a snubber of 100 Ohms and 100 nF. Hundreds of motors having this actuator have worked very well. It happened in some particular place that the motor once started didn't stop, but changing the place it keep working properly. It is the influence of the network of this particular place but I don't know which influence. I have added in series an inductance shifting the current with almost 30 degrees and the TRIAC worked very well.
Could some other inductive loads on this particular network have such a bad influence on the behaviour of the TRIAC? I mean a weak electrical network and some asynchronous motors around. Could you please give me any advice?
PS: I have attached a drawing but I was not able to post it. I hope that this description is good enough.