Overcurrent Deviced include GFCIs,
GFCI (Ground Fault Circuit Interrupter) Outlet
This device is a very inexpensive device to help prevent the burns and electrical shock. A GFCI detects ground faults by monitoring electricity flowing in a circuit. If the current in the circuit suddenly exceeds the GFCI's current threshold, the GFCI will trigger and interrupt the electricity flowing. The tripping speeds for these devices are generally below 25 milliseconds.