I'm planning to use a ACS712 current sense IC to sense motor-current in a project:
http://www.allegromicro.com/~/Media/Files/Datasheets/ACS712-Datasheet.ashx
The device I'm building uses a relay to control 230V to an electrical motor. I want to be able to deliver 2A to the motor.
I want to sense the current to be able to give a ballpark power value, and also to be able to detect short circuit or open circuit.
I've heard that short-circuiting the 230V mains, even in a residential area, can possibly cause currents up to or above 1000 A. This of course means that a fuse in the building will blow.
However, even at 1000A, it may take some time for the fuse to blow. I'm worried (or convinced) that the ACS712 will be obliterated by a 1000A surge, even faster than the fuse can blow (a couple of milliseconds?).
What could I do to alleviate this? I could put a 10 ohm resistor in series with my motor, but that would still put approximately 20A through the resistor, and I'm worried that the resistor will burn out before a 10A fuse will. Also, the resistor would definitely burn during normal operation.
What would be the right way to solve this?