Standard Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules

Abstract

5.1 The design of a photovoltaic module or system intended to provide safe conversion of the sun's radiant energy into useful electricity must take into consideration the possibility of hazard should the user come into contact with the electrical potential of the module. These test methods describe procedures for verifying that the design and construction of the module or system are capable of providing protection from shock through normal installation and use. At no location on the module should this electrical potential be accessible, with the obvious exception of the intended output leads. 5.2 These test methods describe procedures for determining the ability of the module to provide protection from electrical hazards. 5.3 These procedures may be specified as part of a series of qualification tests involving environmental exposure, mechanical stress, electrical overload, or accelerated life testing. 5.4 These procedures are normally intended for use on dry modules; however, the test modules may be either wet or dry, as indicated by the appropriate protocol. 5.5 These procedures may be used to verify module assembly on a production line. 5.6 Insulation resistance and leakage current are strong functions of module dimensions, ambient relative humidity, and absorbed water vapor, and the ground path continuity procedure is strongly affected by the location of contacts and test leads to the module frame and grounding points. 5.6.1 For these reasons, it is the responsibility of the user of these test methods to specify the maximum acceptable leakage current for the dielectric voltage withstand test, and the maximum acceptable resistance for the ground path continuity procedure. 5.6.2 Fifty μA has been commonly used as the maximum acceptable leakage current (see ANSI/UL 1703, Section 26.1), and 0.1 Ω has been commonly used as the maximum acceptable resistance. 5.7 Some module designs may not use any external metallic components and thus lack a ground point designated by the module manufacturer. In these cases, the ground path continuity test is not applicable.