MC4 Solar Connector: Structure, Operating Principle and Use of MC4 solar connectors in Solar Panel Systems

What is an MC4 solar connector? What do these solar connectors have to do and where are they used?

There are multiple types of interlocking PV connectors. This article concerns MC4 solar connectors, but the same principles are valid for other solar connectors such as Amphenol H4, Tyco, and SMK.

What is an MC4 solar connector?

The solar PV panels are attached with solar cables to carry the electricity generated to the solar circuit.

The connection of the solar cables takes place with standardized PV connectors, usually, with the so-called MC4 solar connector.

Most modern solar PV panels are manufactured with wire leads that have MC4 solar connectors on the ends.

MC4 solar connectors are connectors, with the help of which one joins solar cables in the solar PV system. MC4 solar connectors serve for time-saving and secure serial and parallel cabling of modules in solar PV systems.

The “MC” term stands for “Multi Contact” the brand name of a U.S. manufacturer. The digit 4 stands for contact pin cross section in mm².

The advantage of the MC4 solar connectors is that they can be put together manually. Once joined, you can release the plug connection only with a suitable tool. This prevents any unwanted release of the MC4- plug connection if you pull for example a solar cable.

Structure and operating principle of MC4 solar connectors

An MC4 solar connector has a similar structure to a socket. It consists of two parts: female MC4 connector and male MC4 connector.

With MC4 solar connectors, you should only join solar cables, which have a suitable diameter. Otherwise, the connection is not properly closed.

The most appropriate are double isolated solar cables, which have in addition to the conventional isolation a so-called black coat, which protects it from UV light.

Therefore, such solar cables are resistant to sunlight and weather influences, so are safe from heat, moisture and temperature change. Also, MC4 solar connectors have these resistances.

How to connect MC4 solar connectors and MC4 Extension Cables

The solar cables are linked with the aid of two methods:

Typically via the crimping process (a crimp tool is required)

Expert tip: Many cable manufacturers offer a detailed instruction for crimping including indications as to the proper crimp tools and their handling.