Solar extension cable

The Solar extension cable set (20 metres, 6mm²) is the high-performance solution for photovoltaic projects where maximum efficiency and minimum losses over long distances are paramount. If you need to bridge a distance of 20 metres between your solar panels and the inverter, this generous cross-section of 6 mm² provides the necessary capacity to safely transmit the generated energy to its destination without significant heat build-up.

The set includes two high-quality, double-insulated solar cables: a red cable for the positive terminal (+) and a black cable for the negative terminal (-). Both ends are professionally pre-terminated with MC4-compatible plugs and sockets. Thanks to its substantial cross-section, this set is particularly future-proof and ideally suited to modern high-performance modules, which often deliver high currents and where standard cables would already reach their limits over this distance.

Highlights at a glance

• Minimal signal loss: The 6mm² cross-section drastically minimises electrical resistance and ensures a significantly lower voltage drop than conventional 4mm² cables over a distance of 20 metres.
• Plug & Play installation: The cables are pre-fitted with MC4-compatible connectors at both ends, so no special crimping tools are required.
• Reliable identification: The colour-coding – red (+) and black (-) – effectively prevents incorrect polarity and makes installation easier, even with more complex systems.
• Weatherproof & durable: The special cross-linked polyolefin sheath is UV-resistant, ozone-resistant and withstands extreme temperatures ranging from -40°C to +90°C.
• IP67 protection rating: When connected, the connectors are completely dust-tight and protected against temporary submersion (rain/puddles).
• High-quality conductor: Tinned electrolytic copper ensures excellent corrosion resistance and consistently high conductivity, even in demanding environments.

Areas of application

This 20-metre extension cable is optimised for demanding long-distance connections:

• Large balcony power stations & garden installations
  • Ideal for installing panels at the sunniest end of a garden or on a carport and feeding the electricity to the house over a distance of 20 metres with minimal loss.
• Roof-mounted systems & barns
  • Bridging the distance from remote module strings to the point of entry into the building or to the central inverter.
• Off-grid systems (12V / 24V / 48V)
  • Particularly important for battery systems: over a distance of 20 metres, the 6 mm² cross-section ensures that the charging voltage is transmitted with virtually no loss, which noticeably increases the efficiency of your storage system.

Installation & Safety Instructions

• Efficiency benefits over distance
  • With a cable length of 20 metres, 6 mm² offers a significant advantage over 4 mm². The lower resistance ensures a higher system voltage at the inverter and thus a measurably higher yield.
• Strain relief & securing
  • Secure the long cable runs to the mounting frame or in cable ducts every 50–100 cm using UV-resistant cable ties to prevent mechanical strain on the connectors.
• Correct engagement
  • When connecting the cables, make sure that the MC4 connectors click audibly into place. This is the only way to ensure that the connection is permanently watertight and protected against dangerous arcing.

Features

FAQs on the 20m 6mm² solar extension cable

Why should I opt for 6 mm² for a 20-metre cable?

To minimise power loss. With a length of 20 metres (40 metres total distance), the resistance adds up. 6mm² cables have approximately 30% lower resistance than 4mm² cables. This means less heat loss in the cable and more usable energy for your inverter.

Do the connectors fit modules from all major manufacturers?

Yes. The connectors fitted comply with the global MC4 standard. They are a perfect mechanical and electrical match for the connectors used by brands such as Trina, Jinko, JA Solar and Canadian Solar.

Can I shorten the cable if necessary?