I have seen circuit breaker test companies trip 800 amp circuit breakers with a load device. It was the size of a two drawer file cabinet.
I'm not aware of one for small circuits. Done the 'short the circuit' routine myself when the circuit tracer was acting up. The problem is that not all the circuit may be able to take the fault and you'll create an open in a device, box, or worse yet in the wall.
If you get on a circuit with a lot of harmonics or noise the circuit locators go bezerk.
