In solar installations, cable management plays a vital role in both system safety and performance. From the outset of a project, it's important to follow best practices, such as using only connectors from the same manufacturer. Cross-connecting cables or using mismatched connectors can lead to damage, increased contact resistance, or even pose fire risks. Ensuring the correct and consistent use of connectors is essential for long-term system reliability.
Follow the guidelines
Solar modules are typically supplied with a length of cable coupling, one side of which is permanently attached to the module, making it essential to follow proper guidelines from the start to avoid cross-connection issues, and to follow the general rule of only connecting plugs and sockets from the same manufacturer. Mixing connectors from different manufacturers can result in cracks, leaks and increased contact resistance, which in turn can lead to scorching and subsequently fire. Such damage is not always immediately visible and can remain undetected for long periods.
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Over the longer term, connector failures, power losses, failure of strings connecting the modules and even failure of the entire system are all possible. Once again, the worst case scenario is the risk of fire – endangering life, limb and machine.
What does the plug standard say?
In fact, connections do not comply with plug-in standards if plugs and sockets from different suppliers are connected. This is referred to as cross-connection, and in such cases users risk voiding warranties and insurance cover.
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The IEC 62548 installation standard stipulates that the plugs and sockets connected together in a photovoltaic system must be of the same type and manufacturer. For solar modules, the latest version of IEC 61730-1 requires the connector type to be specified on the module label. The installer will then be familiar with which plug to use.
And what does the TÜV say?
Likewise, product certification is avoided in the case of cross-connection. Different standards apply in this context: The product standard for connectors is IEC 62852 (EN 62852). Thereby, if a plug from manufacturer A is connected to a socket from manufacturer B, the certification is annulled.
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Risks of cross-connection
Some manufacturers may refer to compatibility between commonly used MC4 connectors, although this is not actually technically accurate. MC4 is a registered trademark of Stäubli (formerly Multi Contact) and is not an official industry standard. Here, as ever, the cross-installation of components from different manufacturers represents a safety risk.
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Free white paper for safe and secure operation of facilities: The experts at EMC-direct have put together the white paper “Knowing and avoiding common causes of damage to photovoltaic systems” to raise awareness of high quality standards in the assembly and electrical installation of PV systems. Download for free here (German)
Thaddäus Nagy is Executive Director of EMC-direct. In recent years, he and his team have helped construct numerous large-scale open-air solar projects across Europe. Products from this cable protection and fastening specialist based in Dorsten near Gelsenkirchen have been used in major installations across Europe. (HS/TF)
