UL has announced the third issue of the Outline of Investigation for Enclosed and Dead-Front Switches for Use in Photovoltaic Systems. The outline can be purchased on the UL website.
These requirements cover open, enclosed and dead-front switches rated up to 1500 V dc, intended for use in dc photovoltaic (PV) systems and installed in accordance with Article 690 of the National Electrical Code, ANSI/NFPA-70. These switches are intended for ambient conditions between minus 20 to +50°C.
*Description from the UL website.