[General] MCP get tripped when 230 ac bridge rectifier starts working in an SMPS circuit

[jaiju]

I am trying to make an SMPS.
While powering the SMPS ,it is getting tripped.
It works same even we power using 230 VAC without driving signals.(gate trigger)
After MCB get tripped,if i power the PWM driver board(12V), it works fine and gets some voltage in the output and gradually disappears as capacitor discharges completely.
(also SMPS working with 48V dc input with less output voltage)
ie SMPS PWM section and its switching is ok. Also the rectifier capacitor holds
some energy even after the MCB get dripped.

I tested the bridge with multimeter and there is no short in each diodes.
I am not using any EMI filtering coils in the input(230V aC).

Also i have one doubt,
will IRFP460 mosfet gets any kinfd of faulty trigger if the voltage goes to above some level.(my case 230V ac ).

Or is it due to the lack of required number of input wingdings in the power transformer?

please reply and help me...

Attaching the circuit which i taken as reference for my design.

 

[Anna Conda]

What exactly is tripping?

is MCP = mains circuit breaker? if so the ntc might not be reducing the peak inrush current enough and if the breaker is of low value (i.e. < 10A) then it might be responding to the peak inrush current at time of switching on the AC mains.