IEC 62788-1-7:2020 is designed as a more rigorous qualification test, using accelerated UV exposure at elevated temperature to determine whether polymeric encapsulants can suffer loss of optical transmittance. IEC 61215-2 already includes a UV preconditioning test (MQT 10), however, the parameters for that test only represent a limited level of exposure (~weeks of UV dose). This test procedure is intended for representative coupon specimens, applying stress at a greater intensity (designed relative to Phoenix, AZ), using a radiation spectrum that is more similar to the terrestrial solar spectrum, and using a duration of exposure that is more relevant to the PV application (i.e., equivalent to several years of outdoor exposure). This test quantifies the degradation rate of encapsulants so that the risk of the materials losing optical transmittance during operation in the terrestrial environments can be managed. The quantitative correlation between climate (or location of use), a specific application (utility installation, residential-installation, roof-mount, rack-mount, use of a tracker, the system electrical configuration and its operation), and the test can be established for each specific encapsulant material, but is beyond the scope of this document.
