3 Phase 3 wire, 12V Regulator TNY278 based.
I have a failure in front end section. I have used Surge Protect resistors and MOVS to protect the surge when Motor is turned On/Off. Most offen R6, R7, and R8 resistors are burning. I think this is due to surge voltage generated by Motor when it is turning On.
Can any one suggest me how to proetct the front end circuit?