This outline of investigation covers open and enclosed manual and electromechanical disconnect switches intended for disconnecting the output of DC photovoltaic (PV) panels. Manual disconnect switches are intended for installation in accordance with Part III of Article 690 of the National Electrical Code@ NFPA 70. Power operable (electromechanical) disconnect switches are intended for use as disconnecting purposes supplementary to manual disconnecting means that are required by Part III of Article 690 of the National Electrical Code@ NFPA 70. These requirements cover devices rated 1500 V or less and are intended for use in an ambient temperature of -20???C 50??unless specifically indicated for use in other conditions. These devices are intended for use on the load side of PV branch protection devices. These requirements are intended to be used in conjunction with the Standard for Industrial Control Equipment@ UL 508@ except as modified or supplemented by the following requirements.