Reference is now also made to FIGS. B and C which illustrate schematically switch mechanism 703 in more detail. FIG. 7B illustrates switch mechanism 703 in a serial configuration in which switch 703 is connected in series with the serial string 723 and FIG. 7C illustrates a parallel configuration in which switch 703 is connected in parallel with serial string 723. In the serial configuration (FIG. 7B) switch 703 is closed during normal operation of inverter 704. When an island condition is detected, serial switch 703 opens during shut down of inverter 704. Current sensing mechanism 707 upon sensing zero current signals controller 306 that output current is less than a previously specified minimum value and controller 306 shuts down power conversion in converter 705. In the parallel configuration (FIG. 7C), switch 703 is open during normal operation of inverter 704. When an island condition is detected, parallel switch 703 closes during shut down of inverter 704. With all the current of serial string 723 flowing through the switch 703 at minimal load, the current increases to above a previously specified maximum current. Current sensing mechanism 707 upon sensing a current maximum signals controller 306 that output current is above maximal previously specified value and controller 306 shuts down power conversion. Switch mechanism 703 in different embodiments may be embodied by a mechanical switch or a solid state switch with current and voltage ratings appropriate to the present application. Switch mechanism 703 is preferably selected by one skilled in the art of power electronics so that arcing across its open terminals is avoided while practicing some embodiments of the present invention.