IEC 62790:2020 is available as IEC 62790:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 62790:2020 describes safety requirements, constructional requirements and tests for junction boxes up to 1 500 V DC for use on photovoltaic modules in accordance with class II of IEC 61140:2016.
This document applies also to enclosures mounted on PV-modules containing electronic circuits for converting, controlling, monitoring or similar operations. Additional requirements concerning the relevant operations are applied under consideration of the environmental conditions of the PV-modules. This document does not apply to the electronic circuits of these devices, for which other IEC standards apply. This second edition cancels and replaces the first edition published in 2014. This edition includes the following significant technical changes with respect to the previous edition:
- Modifications in normative references and terms and definitions;
- Improvement of declaration of categories for junction boxes in 4.1;
- Clarification for ambient temperature in 4.1;
- Addition of requirement to provide information concerning RTE/RTI or TI in 4.2;
- Reference to IEC 62930 instead of EN 50618 in 4.6;
- Addition of "Functional insulation" in Table 1;
- Addition of "Distance through cemented joints" in Table 3;
- Correction of procedure of process to categorize material groups (deletion of PTI) in 4.15.2.3;
- Requirement for approval of RTE/RTI or TI for insulation parts in 4.16.1 and 4.16.2;
- Change of requirements concerning electrochemical potential in 4.17.2;
- Clarification for IP-test in 5.3.4.2;
- Addition of test voltage for cemented joints in 5.3.6 and 5.3.16;
- Addition of detailled description on how to prepare the test sample for the thermal cycle test in 5.3.9.1;
- New test procedure for bypass diode thermal test (5.3.18) in accordance with MQT 18.1 of IEC 61215-2:2016;
- New test procedure for reverse overload current test in 5.3.23;
- New Figure 1 for thermal cycle test.