1.1 This outline of investigation covers open and enclosed manual disconnect switches intended for
disconnecting the output of DC photovoltaic (PV) panels.
1.2 These controllers are intended for installation in accordance with Article 690 of the National Electrical
Code, NFPA 70.
1.3 These requirements cover devices rated 1500 V or less and are intended for use in an ambient
temperature of -20°C – 60°C unless specifically indicated for use in other conditions.
1.4 These devices are intended for use on the load side of PV branch protection devices.
1.5 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.
UL SUBJECT 508I-2011 history
2015UL SUBJECT 508I-2015 UL Outline for Investigation Manual Disconnect Switches Intended for Use in Photovoltaic Systems (Issue 2)
2011UL SUBJECT 508I-2011 Outline of Investigation for Manual Disconnect Switches Intended for Use in Photovoltaic Systems