6 Tips for installing the MC4-Evo 2 connectors & DC cables

What should you pay attention to when installing the MC4-Evo 2 connectors into the DC cables? Let's follow 6 important notes when installing.

The MC4-Evo 2 connectors & DC cables

Currently, using renewable energy sources is gradually becoming popular and being applied in every country. In Vietnam, Power Plan VIII has just been approved, which opens huge opportunities for the solar energy sector. However, when solar energy projects begin to be installed and put into operation, they have some performance problems, even fires and explosions.

In the seminar on MC4-Evo2 cable connectors that we recently organized in September, Mr. Joseph Yang - Director of Stäubli company (Taiwan branch) shared one of the errors that cause the greatest damage to solar energy systems. The problem comes from a lack of knowledge about the system's components, leading to incorrect installation. Therefore, to ensure the safety and efficiency of the system, in this article, we will bring 6 important notes that you need to consider when installing a solar energy system, specifically installing MC4-Evo2 connectors to DC cables.

1. Cable quality

• Electrical cables (conductors) used during the installation of the photovoltaic systems must be intact and not scratched or deformed.

• The protective cover of the cable is not scratched, shows no signs of fading, and still retains its flexibility.

2. Minimum tolerance

When stripping cables, the stripped core must have a length between 6 and 7.5 mm. If the core length is shorter or longer than this range, it will affect the contact resistance of the cables and connectors.

3. Crimp sleeves (cos)

• All of the strands have been captured in the crimp sleeve (cos)

• The crimp sleeve is not deformed or missing any portion of the crimp flaps, the crimp is symmetrical

• A “brush” of conductor strands is visible on the contact side of the crimp.

4. Assembly check

We tend to distinguish the male and female heads of MC4-Evo2 based on the outer protective shell. However, the MC4-Evo 2 connector is identified by the internal crimp sleeve (cos). The end with the socket is female, and the end with the plug is male.

5. Connector tightening

When tightening the cable end, we should use a specialized toolset to achieve the highest precision. According to instructions from Stäubli, if tightened correctly, the nut should not be close to the body but must be a certain distance away (depending on the diameter of the PV wire). You should refer to the parameters given by the wire manufacturer.

6. Bending radius

Bending radius is the last important point you need to keep in mind. The minimum bend radius of the DC cable from the cable connector is 20mm. If the wire is bent at a point less than 20mm, it will lead to problems such as increased resistance and increased temperature leading to damage to the solar system.

With 6 important notes when installing the MC4-Evo 2 cable connector to the DC cable that we mentioned above, depending on each specific situation, you can consider adjusting or referring to parameters from the producer. In case you need more in-depth advice on installation or how to choose a specialized DC cable line, please contact our engineer for a quick answer.

For more information, please contact:


905 Nguyen Kiem Street, Ward 3, Go Vap District, Ho Chi Minh City 700000, Vietnam

Tel. +84 28 22536441 | info@helukabel.com.vn | www.helukabel.com.vn