Mains short circuit protection and switch out.

[Faringdon]

Hi,
You are kindly requested to  propher  your fave short circuit switch-off for mains. ie, 230vac mains gets a short circuit, and you want to switch it off. (short circuit from line to neutral)

Eg, back2back IGBTs  in the neutral with a isolated supply feeding their gate drivers...and a comparator and sense resistor etc, to switch off the igbtS When sht cct occurs.
or
Overcurrent sensor and relay with relay snubber.
or
Back2back FETs in neutral.....and they are controlled for say 30A to 0A over some 2 seconds when sht cct occurs.

Whatever it is, it cant just be back2back FETs in neutral, then turn them off simply when overcurrent occurs..since FETs will explode if not "nannied" off with such high current and voltage cct.

[Gyro]

A BS1362 fuse.

[themadhippy]

Depends on the trip characteristics im after,if it needs to deal with a large start up current then a 10mm bolt,if however it needs to be a fast acting device a bit of silver paper.

[MF-jockey]

You should never install a fuse or circuit breaker in the neutral wire. The shutdown must always take place in the phase. Normally you take a circuit breaker with a rated current that matches the cable cross section.
https://www.amazon.co.uk/Schneider-EZ9F16120-Miniature-Circuit-Breaker/dp/B00WRBRAGW/ref=sr_1_1

[Gregg]

Keep it simple --- use a fuse!
Over complicating things seldom is necessary unless you are planning obsolescence!