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 large distances. If your solar modules have to be positioned in the sunniest place on your property – for example, at the end of an extensive garden, on a distant barn or in an open field – and the inverter is to remain centrally located in the building, this set bridges the distance safely and reliably.

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

Highlights at a glance

• Maximum range: With 35 metres length per cable, you can also implement complex installation scenarios far away from the house connection or main meter.
• Plug & Play installation: The cables are pre-assembled with MC4-compatible connectors on both sides, so no special crimping tools are required.
• Secure identification: The clear colour coding in red (+) and black (-) effectively prevents dangerous polarity confusion over this long cable run.
• Weatherproof & durable: The special sheath made of cross-linked polyolefin is UV-resistant, ozone-resistant and withstands extreme temperatures from -40°C to +90°C.
• IP67 protection class: The plug connections are absolutely dust-tight when plugged in and are protected against temporary immersion (e.g. in heavy rain or puddles).
• 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 in a field, where there is no shadow cast by buildings or tall trees.
• Outbuildings & agriculture
  • Connecting remote garages, carports, sheds or stables with the main building.
• Indirect cable routing
  • When cables cannot be laid directly, but must be routed around the whole house or through extensive empty conduit systems.

Installation & safety instructions

• Voltage drop (Important!)
  • At a length of 35 metres, the total circuit 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 massive voltage loss; in this case 10mm² or 16mm² cross-sections must be used.
• Laying in the ground
  • Although the cable is weatherproof, it is not protected against mechanical influences (spade cuts, rodents). When laying underground, you must always use a protective conduit (e.g. flexible conduit or cable protection pipe).
• Avoid induction & heat
  • Never coil excess cable into a tight spool while current is flowing, as this can result in induction and heat build-up. Lay excess cable in wide loops ("meanders").

Features

FAQs on the 35m solar extension cable

Is 4mm² really still sufficient for a length of 35 metres?

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

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

Yes. The connectors used comply with the worldwide MC4 standard used in almost all modern solar modules and micro-inverters. They fit mechanically and electrically perfectly.

Can I shorten the cable if necessary?