OK Mr. Danger, mathematically all is safe with those resistors, but for any failure here (it doesnt have to be a failure of a component during regular work, maybe you will drop a screw inside during testing or sth like that) I would not like to wait for the 16A circuit breaker in the wall to drop, I would like 250mA fuse to disconnect right there.

 

It looks like the peak voltage at the non-inverting input is less than +/-0.3 V

ak

Got it, it won’t damage the opamp.
But without a negative supply, it will still clip the negative excursions. The result is that only a half wave will be sampled.
He either needs to add a virtual ground or a charge pump to generate the negative supply.

 

We still don't know why he is sampling the mains voltage, so it might not be an issue. If all he wants is a peak value to turn into an quasi-RMS value for display, half-wave rectification of any kind should be ok.

ak

 

I would like 250mA fuse to disconnect right there.

Digi-Key has 5mm fuses down to 32 mA, with or without axial leads.

ak