Stäubli MC4 Connectors are built for joining solar panels together with weather-tight low-resistance contacts. They are the industry-standard for photovoltaic (PV) quick connectors.
Contact pins within the housing are crimped onto the PV wiring. The housing is added over the top and snapped into place, with a weatherproof jacket tight between the wire and the housing to prevent moisture from reaching the contacts.
Connectors create a waterproof seal, and the contact pins within them create a connection point to allow the electricity from the solar panels to flow. The insulating plastic housings lock together to prevent the wire from disconnecting unintentionally.
The Stäubli Open-Ended Spanner within the MC4 Tool Kit can unlock the connectors. Only disconnect when panels have zero load to mitigate risk of serious injury or death.
Stäubli MULTILAM contact pins are made of tin plated copper. The insulating housing is made of plastics known as PA (Polyamide) and PC (Polycarbonate), which are durable and wear-resistant to withstand decades of harsh sun exposure and weather conditions.
MC4 connectors are meant to connect only to other MC4 connectors of the same model. If mixed with other brands or models, the contact pins may not sit properly and create an arc, which can lead to a fire.
Each set includes five plug ends and five socket ends, a total of 10 end pieces, which makes five connector pairs. Use the Stäubli MC4 Tool Kit and follow the installation procedure to achieve an IP68 rating.
MC4 stands for “Multi-Contact 4mm,” which refers to the original manufacturer and the diameter of the contact pins. The MC4 connector is the successor to the MC3 connector (Multi-Contact 3mm), and it gained a larger contact pin and a locking mechanism.
The MC4-Evo 2 connectors are suited for high voltage solar systems and are designed to withstand both ammonia and salt mist spray. This makes them ideal for areas high in humidity or pollutants.
Multi-Contact released the original MC3 connector in 1996. Stäubli purchased Multi-Contact in 2002, though they kept the name for the quick connectors. Stäubli released the MC4 connectors in 2004.
In 2008, the National Electric Code established that all PV connectors needed to have the locking mechanism. The MC4 connector became more popular than the MC3 connector due to this, and the MC3 connector has been discontinued as of 2016.
