UL 61215-2-2021 pdf download – Terrestrial Photovoltaic (PV) Modules – Design Qualification and Type Approval – Part 2: Test Procedures.
4.2.3 Procedure Determine the current-voltage characteristic of the module in accordance with IEC 60904-1 at a specific set of irradiance and temperature conditions (a recommended range is a cell temperature between 20 °C and 50 °C and an irradiance between 700 W/m 2 and 1 100 W/m 2 ) using the apparatus described in 4.2.2. In special circumstances when modules are designed for operation under a different range of conditions, the current-voltage characteristics can be measured using temperature and irradiance levels similar to the expected operating conditions. For linear modules (as defined in IEC 60904-10) temperature and irradiance corrections can be made in accordance with IEC 60891 in order to compare sets of measurements made on the same module before and after environmental tests. For nonlinear modules (as defined in IEC 60904-10) the measurement shall be performed within ±5 % of the specified irradiance and within ±2 °C of the specified temperature. However, every effort should be made to ensure that peak power measurements are made under similar operating conditions, that is minimize the magnitude of the correction by making all peak power measurements on a particular module at approximately the same temperature and irradiance. For flexible modules, the maximum power determination shall be measured with the flexible module in the flat position.
4.3.5 Test requirements a) No dielectric breakdown or surface tracking. b) For modules with an area of less than 0,1 m 2 the insulation resistance shall not be less than 400 MΩ. c) For modules with an area larger than 0,1 m 2 the measured insulation resistance times the area of the module shall not be less than 40 MΩ·m 2 . 4.4 Measurement of temperature coefficients (MQT 04) Determine the temperature coefficients of current (α), voltage (β) and peak power (δ) from module measurements as specified in IEC 60891. The coefficients so determined are valid at the irradiance at which the measurements were made. See IEC 60904-10 for evaluation of module temperature coefficients at different irradiance levels. For bifacial modules determine the temperature coefficients utilizing the same procedure, but insuring no backside irradiation. The backside shall be covered such that the contribution from the non-exposed side of the module is limited to or below the levels specified for “non-irradiated background” in IEC TS 60904 1-2. If open-circuit voltage or short-circuit current cannot be measured due to module-integrated electronics, the associated temperature coefficient shall be reported as “not measurable due to module-integrated electronics.” Open-circuit voltage or short-circuit current shall not be determined by any method other than direct measurement, such as extrapolation. NOTE For linear modules in accordance to IEC 60904-10, temperature coefficients are valid over an irradiance range of ± 30 % of this level. 4.5 Placeholder section, formerly NMOT The nominal module operating temperature (NMOT) test, formerly MQT 05, is no longer a part of this document. This subclause is preserved so that, in the following subclauses of the document, the MQT numbers match the subclause numbers.