Cable for solar panels

In a solar power system, a cable is not a consumable item but a system component designed to last 25+ years. An ordinary installation wire exposed to outdoor conditions degrades within 3–5 years: insulation cracks under UV radiation, and conductors oxidize due to moisture. A solar cable is specifically designed for outdoor operation from day one. The Altek catalog offers solar cables with cross-sections of 4 mm² and 6 mm² for direct current applications in solar power systems.

Solar Panel Cable: Types and Applications

Two types of cables are used in solar systems, each serving a different purpose.

A DC cable (direct current) connects solar panels to one another and to the inverter. It operates outdoors and withstands DC voltages of up to 1500 V. For this purpose, a specialized solar panel cable with double insulation compliant with EN 50618 / IEC 62930 standards is used.

An AC cable (alternating current) runs from the output of the inverter to the distribution board. Standard power cables with protection against mechanical damage are typically used in this section.

The Altek catalog includes solar battery cables and solar panel cables with cross-sections of 4 mm² (red and black) and 6 mm², available in 500-meter reels or cut-to-length sections.

How to Choose a Solar Panel Cable

The conductor cross-section is the key parameter. It depends on the current and cable run length. General guidelines:

• 4 mm² – for cable runs up to 15–20 m with currents up to 20 A. Suitable for most residential solar power systems rated at 3–8 kW.
• 6 mm² – for longer cable runs (over 20 m) or currents of 20–30 A. Reduces power losses to an acceptable 1–2%.

Current calculation formula: I = P ÷ U MPPT. For a 5 kW system with an MPPT voltage of 250 V: 5000 ÷ 250 = 20 A. Power losses on a 6 mm² cable over a 20 m run at this current are approximately 1%, which is acceptable.

Color coding. Red indicates positive (+), black indicates negative (–). Proper marking is mandatory according to electrical safety regulations. Both colors are available separately in the Altek catalog.

Solar Battery Cable: Requirements and Specifications

A specialized solar cable compliant with EN 50618 offers characteristics that standard cables do not:

• UV-stabilized double insulation – withstands more than 30 years of ultraviolet exposure without cracking.
• Operating temperature range of –40 to +120°C – the cable remains reliable even when installed on panel surfaces during hot summer days.
• Operating voltage up to 1500 V DC – suitable for most solar systems, including industrial installations.
• Flexible multi-strand construction – simplifies installation in hard-to-reach areas such as under roofs, inside cable ducts, and on support structures.
• Resistance to moisture, ozone, and chemical exposure – essential for outdoor installations and industrial environments.

Using standard PVC installation wire or NYM cable in the DC section of a solar system violates safety requirements and the warranty conditions of most inverter manufacturers.

Solar Cable for PV Systems: Connection Features

Solar panel connection cables are terminated with MC4 connectors, the industry standard. These connectors provide waterproof IP67-rated connections without additional sealing. Important guidelines:

• MC4 connectors must be crimped using a dedicated tool; otherwise, the connection may be unreliable.
• Connectors from different manufacturers (Stäubli, Amphenol, Phoenix) are not always compatible and should not be mixed.
• Series connection of solar panels increases voltage, while parallel connection increases current. The cable should be selected based on the total current of the string rather than the current of an individual panel.
• The minimum bending radius must be at least five cable diameters. When routing under roofing, use cable ties at intervals of 30–40 cm.

Buy Solar Panel Cable in Ukraine

At Altek.ua, you can purchase solar panel cables with 4 mm² and 6 mm² cross-sections in the required length or in full reels. Delivery is available throughout Ukraine from warehouses in Kyiv and Dnipro. Current prices are listed in the catalog. Orders can be placed online or by phone. When purchasing a complete solar power plant package, an Altek manager will calculate the required cable length free of charge.