The solar MC4 connector branch is at the forefront of innovation and quality in the photovoltaic industry. As the industry continues to grow and evolve, the importance of reliable and efficient connectors cannot be overstated. Manufacturers and industry professionals must remain vigilant in ensuring that only high-quality, compliant connectors are used to safeguard the integrity and performance of photovoltaic systems.
The solar MC4 connector has become a synonymous term for photovoltaic connectors among industry professionals. Its presence is ubiquitous in critical components of photovoltaic power generation systems, such as modules, combiner boxes, and inverters, playing a vital role in ensuring successful connections within the power station.
As of March 2021, China's cumulative installed solar power capacity reached 259GW, ranking first globally. With an estimate of approximately 3,000 sets of photovoltaic connectors used per megawatt, China currently has about 777 million connectors installed. From a risk perspective, this translates to at least 777 million potential risk points that different power station owners need to monitor.
Despite its significance, this small component is often overlooked during the design, construction, and operation and maintenance stages of power stations. The years 1996 and 2002 were pivotal for photovoltaic connectors, coinciding with key developments in the solar industry. Prior to 1996, photovoltaic cables were connected using screw terminals or splice connections. However, as the installation of solar systems increased, the industry demanded faster, safer, and easier-to-operate connection solutions.
Connectors must withstand harsh environments such as rain, wind, intense sunlight, and extreme temperature changes, while also being waterproof, heat-resistant, UV-resistant, touch-protected, high-current-carrying, and efficient. Low contact resistance is also a crucial consideration, all of which must be maintained throughout the entire life cycle of the photovoltaic system, typically spanning at least 20 years.
In 1996, based on these application environments and market demands, a new type of plug-in connector emerged—the MC3, the world's first true photovoltaic connector. Invented by Swiss company Multi-Contact (later acquired by Stäubli in 2002 as its electrical connector brand), MC stands for the company's abbreviation, and 3 represents the size of the metal core diameter. The MC3's body is made of TPE material (thermoplastic elastomer) and achieves physical connection through friction fit. More importantly, its connection system uses MULTILAM technology to ensure long-lasting stability.
In 2002, the introduction of the MC4 redefined photovoltaic connectors, achieving true "plug and play" functionality. With insulation material made of rigid plastic (PC/PA), it is easier to assemble and install on-site. The MC4 quickly gained market acceptance and became the standard for photovoltaic connectors. Many manufacturers refer to their connectors as "XX MC4," and a search on Alibaba for MC4 yields about 44,000 related products, highlighting the strong market influence of MC4.
The MC4 connector line has evolved to meet customer demands for 1500V photovoltaic systems, with options such as MC4-Evo2 and MC4-Evo3 series. The MC4 connector consists of metal and insulating parts. MC stands for Multi-Contact, and 4 represents the size of the metal core diameter. It is important to clarify that many connectors labeled as "MC4" by other manufacturers are more appropriately termed "MC4-like" due to differences in appearance and, crucially, the absence of MULTILAM technology.
MULTILAM technology ensures long-term stability and maintains consistently low contact resistance throughout the life cycle of the photovoltaic system. "MC4-like" connectors, marketed as interoperable with MC4, may pose hidden safety risks due to variations in specifications, dimensions, and tolerances among different manufacturers. Forcing interoperability can lead to increased temperatures, changes in contact resistance, and compromised IP ratings, severely affecting the power generation efficiency and safety of the system.
