Installing MC4 Solar Connectors

The MC4 connector has become the standard for connecting to solar panels, it is IP67 rated being both water and dustproof, they are relatively simple to install with the correct tools and luckily these tools and getting cheaper and cheaper.

Most solar panels already come with a male and female MC4 connector already fitted for ease of connection.

Today I am going to show you how to crimp on your own MC4 connectors using a cheap crimping tool kit that is available from eBay and amazon.

Click here to order your own MC4 Crimping Kit from Amazon UK

So what we get in your MC4 crimping kit

• A ratchet crimping tool
• 2 X MC4 spanners, for assembling and disconnecting the connectors.
• 10 Compete MC4 plastic male/female connectors bodies.
• 10 Female metal ferrules and 10 Male metal ferrules  

All you will probably need now is some wire cutters and strippers and you are ready to install your own connectors.

Each MC4 connector is made up from a male and female plastic parts and male and female metal ferrules, the male metal ferrule fits inside the female plastic body and vice versa.

How to release the male/female parts

The plastic parts normally come already clipped together, you can use your fingers to release the clips holding the male/female parts together, but it is much simpler and safer to use the two prongs on the end of the blue plastic MC4 spanners provided.

Crimping on the connector

First we need to stripped back the plastic coating to expose approximately an 1/2 inch / 12 mm of the copper wire.

We are now going to crimp on the male metal ferrule.

Push the stripped wire into the ferrule so that the insulation is pressed up to the tabs we are going to crimp.

Then depending on the wire size select the smaller position on the crimp tool for 2.5mm, the middle for 4mm and the largest for 6mm wire, there are normally marked with the correct sizes.

The ferrules tabs should point towards the top of the crimp tool so that as they are crimped  the tabs are folded over to tightly grip the exposed wire.

You can use the ratchet on the crimp tool to hold the ferrule while you insert the wire into the correct position before crimping.

Now push the male metal ferrule into the back end of the plastic female connector as until it clicks home.

If you are using the 6mm cable, you may have to unscrew the cap and removed the silicon seal with its crown clamp ring and push these onto the cable first before pushing the ferrule into the body of the connector.

Then push the silicon seal carefully in to the connector body and then lightly screw down the cap.

You should then use the MC4 spanners to tighten the cap firmly onto the body so that no screw thread is visible, at which point the connector will click, it should now fully tightened and sealed, best to give it a visual inspection to make sure you have not crossed the threads 🙁

We have now completed one end of the mc4 connector, we now repeat the process but using the male plastic connector and the female metal ferrule to make up the other side of the connecter.

Also see
Planning for Solar Panels – Part 1
Planning for Solar Panels Part 2 – Panel Mounting Options
Planning for Solar Panels Part 3 – Types of Panels
Planning for Solar Panels Part 4 – MPPT vs PWM solar controllers
Planning for Solar Panels part 5 – Cable sizes, lengths and resistance.
Planning for Solar Panels part 6 – Panels in Serial or Parallel

Safety Disclaimer