In some embodiments, circuitry 110 can lose power when the module is insufficiently illuminated unless its power supply obtains power from a source other than the PV module, such as the AC grid. Circuitry 110 can turn on around sunrise and turn off around sunset so the module is in a well-defined state when circuitry 110 is first powered each day. Circuitry 110 can reset due to loss of power if external influences, such as array current, cause the power supply to be unable to operate due to the voltage across the PV module. When a load is connected to the array, such as when a DC disconnect switch on the inverter is closed, a large current can flow from the PV modules, which can cause circuitry 110 on one or more modules to reset. In such a circumstance, the PV module can repeatedly reset while, for example, input capacitors on the inverter charge. Circuitry 110 can detect such a condition through measurements (e.g., 142b) of the module or by measuring the time that the power supply was unable to operate, and can modify its behavior while the condition persists. During normal operation, circuitry 110 can remain powered and the module would remain enabled.

Turning now to FIG. 3, a flow chart illustrating a method for enabling or disabling PV modules is shown, according to some embodiments. In various embodiments, the method of FIG. 3 may include additional (or fewer) blocks than illustrated.