Solar extension cable 35m 4mm² – red/black for reliable PV connections (set)

The Solar extension cable set (35 metres, 4mm²) is the specialised solution for photovoltaic projects with very long distances. If your solar modules need to be placed at the sunniest spot on your property – for example, at the end of a spacious garden, on a distant barn, or in an open field – and the inverter should remain centrally inside the building, you can safely and reliably bridge the distance with this set.

The set includes two high-quality, double-insulated solar cables: one red cable for the positive pole (+) and one black cable for the negative pole (−). Both ends are professionally pre-assembled with MC4-compatible plugs and sockets. Owing to the considerable length of 35 metres (70 metres total length in the circuit), this set is primarily intended for systems with high string voltage to keep the percentage line losses within acceptable limits.

Highlights at a glance

• Maximum range: With 35 metres of cable length per wire, you can realise even complex installation scenarios far from the house connection or main meter.
• Plug & play installation: Both ends of the cables are fully fitted with MC4-compatible connectors, so no special crimping tool is required.
• Secure identification: The clear colour coding in red (+) and black (−) effectively prevents dangerous polarity mix-ups along such a long route.
• Weatherproof & long-lasting: The special cross-linked polyolefin sheath is UV-resistant, ozone-proof and withstands extreme temperatures from –40°C to +90°C.
• IP67 protection: When plugged together, the connections are absolutely dust-tight and protected against temporary immersion (e.g. during heavy rain or puddle formation).
• High-quality conductor: Tinned electrolytic copper ensures maximum corrosion resistance and permanently excellent conductivity.

Areas of application

This 35-metre extension is intended for specific scenarios:

• Ground-mounted systems
  • Ideal for installing modules far away in the garden or on a meadow, where no shadows are cast by buildings or tall trees.
• Outbuildings & agriculture
  • Connecting remote garages, carports, sheds, or stables to the main building.
• Indirect cable routing
  • When cables cannot be laid directly, but have to be routed around the entire house or through extensive empty conduit systems.

Installation & safety instructions

• Voltage drop (Important!)
  • With a length of 35 metres, the total distance for the current is 70 metres. For grid-connected systems with high string voltage (> 100V), 4mm² is acceptable. For 12V or 24V off-grid systems, this cable is not suitable due to the significant voltage drop; here, cross-sections of 10mm² or 16mm² should be used.
• Burial in the ground
  • Although the cable is weatherproof, it is not protected against mechanical influences (spade cuts, rodents). When installing underground, it is essential to use a protective tube (e.g. flexible conduit or cable duct).
• Avoid induction & heat
  • Never coil excess cable tightly when current is flowing, as this may cause induction and heat build-up. Route any extra length in wide loops (“meanders”).

Features

FAQs about the Solar Extension Cable 35m

Is 4mm² really sufficient at 35 metres length?

Technically safe for high-voltage systems, borderline for maximum efficiency. With a typical balcony system (approx. 40V module voltage, 10A current) you have a voltage drop of around 3 volts at 35m. This corresponds to a power loss of about 7.5%. That is technically safe, but no longer optimal. If you want to optimise yield, you should definitely upgrade to 6mm² cable at this extreme length.

Will the plugs fit my inverter from Hoymiles, Deye or Growatt?

Yes. The installed connectors correspond to the world-wide MC4 standard, which is used with almost all modern solar modules and micro inverters. They fit mechanically and electrically without issue.

Can I shorten the cable if required?