Solar extension cable 40m 6mm² - red/black for reliable PV applications (set)

The solar extension cable set (40 metres, 6mm²) is the specialised solution for photovoltaic projects with extreme distances. If your solar modules need to be positioned in the sunniest part of the property – for example, at the end of a very large garden or in a distant paddock – and the inverter is placed centrally in the building, this generous 6mm² cross-section provides the necessary capacity to effectively minimise power losses over the entire 40-metre distance.

The set includes two high-quality, double-insulated solar cables: a red cable for the positive pole (+) and a black cable for the negative pole (−). Both ends are professionally pre-assembled with MC4-compatible plugs and sockets. Thanks to the massive cross-section, this set is particularly future-proof and ideal for modern high-performance modules, where standard cables (4mm²) would already show significant efficiency losses over this enormous distance.

Highlights at a glance

• Optimised for long distances: The 6mm² cross-section significantly reduces electrical resistance, which is crucial for a high energy yield over 40 metres (80m total route).
• Plug & Play installation: The cables are pre-assembled on both sides with MC4-compatible connectors, so no special crimping tools are required.
• Safe identification: The clear colour coding in red (+) and black (−) effectively prevents dangerous polarity mix-ups when installing over long distances.
• Weatherproof & durable: The special jacket made of cross-linked polyolefin is UV-resistant, ozone-resistant and withstands extreme temperatures from −40°C to +90°C.
• IP67 protection: The connectors are absolutely dustproof and protected against temporary submersion (e.g. in heavy rainfall) when plugged in.
• High-quality conductor: Tinned electrolytic copper ensures maximum corrosion resistance and consistently excellent conductivity, even under adverse conditions.

Areas of application

This 40-metre extension is designed for demanding long-distance connections:

• Large ground-mounted systems
  • Ideal for installing modules far away in the garden or in a meadow where there is no shadow cast by buildings.
• Outbuildings & agriculture
  • Connecting distant garages, carports or stables to the main building or the central meter cupboard.
• Stand-alone systems (24V / 48V)
  • The 6mm² cross-section over 40 metres is particularly important for battery systems to keep the charging voltage stable and losses low.

Assembly & safety instructions

• Efficiency over distance
  • With a cable length of 40 metres, 6mm² provides a significant advantage over 4mm². The lower resistance ensures higher system voltage at the inverter and thus measurably higher yields over the years.
• Protection for underground installation
  • Although the cable is weatherproof, if it is to be laid in the ground it must always be routed in a suitable protective conduit to protect it from mechanical impact and rodents.
• Correct latching
  • When connecting, make sure that the MC4 connectors engage audibly. This is the only way to ensure the connection is permanently watertight and safe against dangerous arcing.

Features

FAQs on the solar extension cable 40m 6mm²

Why is 6mm² at 40 metres better than 4mm²?

Because of the lower voltage drop. Over a total length of 80 metres (out and back), the electrical resistance adds up. A 6mm² cable reduces this resistance by about a third compared to a 4mm² cable, which can mean several percent higher yield in typical balcony systems or module strings.

Do the connectors fit my inverter from Hoymiles, Deye or Growatt?

Yes. The connectors used conform to the worldwide MC4 standard. They fit mechanically and electrically perfectly to almost all common solar modules and inverters.

Can I shorten the cable if 40m is too long?