Because the controller 212 relies on both current and voltage to determine whether a short circuit occurred on the system line 130, the device 120 is able to be more robust than devices that only monitor a single input. For example, in comparison with a typical isolator, the device 120 may more precisely recognize an actual short circuit.

The controller 212 may open or close the isolation switches 210 based on whether it has determined that there is a short circuit or not. For example, the controller 212 may send a control signal to open or close the isolation switches 210. In an aspect, the control signal may be sent via switch control line 218.

The controller 212 may contain various counters and timers for counting false positives (transients) and true (actual) positives; and for allowing certain predetermined intervals of time to pass before initiating certain actions.

To conserve power, the controller 212 may resort to a sleep mode until it receives an alert signal from either the current alert comparator 226 and/or the voltage comparator 233, 234, or receives a periodic wake-up signal.

FIG. 3A, provides a high-level view of exemplary operations 300 of the controller 212 when an anomaly such as a short circuit is detected and wakes up the controller. Initially, at 302, the controller 212 may receive an indication of a short circuit being detected as described above. After a delay at step 306, the controller verifies whether a short is still present (step 310). The duration of the delay in step 306 may depend upon several factors and is discussed in more detail with respect to FIGS. 4A and 4B.