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I. Product Introduction
A twin DC solar cable is a specialized electrical cable designed for direct current (DC) power transmission within photovoltaic (PV) systems. It features two insulated conductors encased within a single outer sheath, streamlining the wiring process compared to using two separate single - core cables. This design is highly efficient for connecting solar panels to each other, as well as for transmitting power from panels to inverters, batteries, or the electrical grid in DC - based solar setups.
II. Structure and Materials
2.1 Conductor
Material: Typically made of high - purity oxygen - free copper (≥99.97%), often tinned to enhance corrosion resistance. The tinned surface helps prevent oxidation, ensuring stable electrical conductivity over time, especially in outdoor environments exposed to moisture and humidity.
Stranding: Usually stranded to improve flexibility, making it easier to route around complex structures during installation, such as rooftops with multiple obstacles or in tight conduits.
2.2 Insulation Layer
Inner Insulation: Cross - linked polyethylene (XLPE) or cross - linked polyolefin (XLPO) is commonly used. These materials offer excellent electrical insulation properties, protecting against electrical leakage and short circuits. They also have high thermal stability, allowing the cable to operate reliably within a wide temperature range, from extremely cold (-40°C) to high - heat (+90°C) conditions.
Insulation Thickness: Varies depending on the cable's voltage rating and application requirements, but it is carefully designed to balance insulation performance and overall cable size.
2.3 Outer Sheath
Material: Constructed from UV - stabilized, halogen - free thermoplastic elastomer (TPE). This outer layer provides robust protection against environmental factors. It resists long - term UV radiation, which can degrade the cable over time, as well as moisture, abrasion, and mild chemicals.
Color Coding: Often color - coded for polarity identification. For example, a black outer sheath may indicate the negative conductor, while a red or brown sheath could signify the positive conductor, simplifying correct connection during installation.
III. Technical Specifications
Parameter | Common Values |
Rated Voltage | 1000V DC or 1500V DC |
Current - Carrying Capacity | Varies by cable size (e.g., 4mm² twin cable: 32A per core, 64A in total) |
DC Resistance | Depends on conductor size and material (e.g., for 4mm² copper conductor: ≤4.61Ω/km per core) |
Overall Diameter | Ranges from 6 - 10mm based on size and insulation thickness |
Minimum Bend Radius | Usually 6 - 8 times the cable diameter to prevent damage to insulation and conductors |
Flame Retardancy | Complies with international standards like IEC 60332 - 1 - 2 to ensure safety in case of fire |
Certifications | TÜV EN 50618, IEC 62930, UL 4703, RoHS, indicating compliance with global quality and safety requirements |
IV. Key Features
4.1 Simplified Installation
The twin - core design integrates both the positive and negative conductors within one sheath, reducing installation time and effort. Installers can route the cable as a single unit, eliminating the need to manage two separate single - core cables. This also minimizes the risk of incorrect polarity connections, which can lead to system malfunctions or damage to equipment.
4.2 Reliable Power Transmission
With high - quality copper conductors and excellent insulation, twin DC solar cables ensure efficient power transfer with minimal power loss. The low electrical resistance of the conductors allows for the smooth flow of direct current, optimizing the performance of the entire PV system.
4.3 Durable and Long - Lasting
The combination of XLPE or XLPO inner insulation and TPE outer sheath provides superior protection against harsh outdoor conditions. The cables can withstand extreme temperatures, strong sunlight, rain, snow, and mechanical stress, ensuring a long service life of 15 - 25 years or more, depending on the environment and usage.
4.4 Safety Assurance
Certified to meet strict international safety standards, twin DC solar cables offer reliable protection against electrical hazards. Their flame - retardant properties and proper insulation prevent electrical fires and ensure the safety of the PV system and its surroundings.
V. Applications
5.1 Residential Solar Systems
Ideal for connecting rooftop solar panels in homes. Whether it's a small - scale residential setup with a few panels or a larger system, twin DC solar cables can efficiently transmit the generated DC power from the panels to the inverter, enabling households to utilize clean, renewable energy for their daily electricity needs.
5.2 Commercial and Industrial Solar Installations
Used in commercial buildings such as offices, shopping malls, and industrial facilities with large - scale solar arrays. These cables can handle the higher power outputs of numerous solar panels, ensuring the reliable transfer of DC power to the building's electrical infrastructure or for feeding into the grid.
5.3 Off - Grid and Remote Area Power Systems
Crucial for off - grid solar setups in remote locations like rural villages, islands, or remote research stations. They enable the connection of solar panels to batteries for energy storage and subsequent distribution to electrical loads, providing a stable and sustainable power supply where access to the main electrical grid is limited or unavailable.
5.4 Solar - Powered Devices and Micro - Grids
Suitable for powering various solar - powered devices, including solar streetlights, water pumps, and small - scale monitoring systems. In micro - grid applications, twin DC solar cables help in the efficient distribution of power within the local network, ensuring the proper functioning of all connected devices.
VI. Installation and Maintenance
6.1 Installation Guidelines
Termination: Use appropriate connectors rated for the cable's size, voltage, and current capacity. Popular choices in PV systems include MC4 connectors, which are known for their reliable and weatherproof connections. Ensure proper crimping or soldering of the connectors to create a secure electrical link.
Routing: When routing the cable, follow the minimum bend radius requirements to avoid damaging the insulation and conductors. Use cable clips, conduits, or trays to support and protect the cable, especially in areas where it may be exposed to mechanical stress, such as around sharp corners or in high - traffic zones. Keep the cable away from other electrical cables to prevent electromagnetic interference.
Polarity Check: Double - check the polarity of the cable connections before powering on the system. Incorrect polarity can cause damage to the inverter, batteries, or other components.
6.2 Maintenance Tips
Regular Inspection: Periodically inspect the cable for signs of damage, such as cuts, cracks, or discoloration of the insulation. Pay close attention to the connection points for any signs of overheating, corrosion, or loose connections. Early detection of issues can prevent costly repairs or system failures.
Cleaning: If dirt, dust, or debris accumulates on the cable, clean it gently with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that could damage the outer sheath and compromise the cable's protective properties.
Performance Monitoring: Periodically measure the insulation resistance and DC resistance of the cable to assess its performance. A significant decrease in insulation resistance or an increase in DC resistance may indicate internal damage or degradation, and the cable may need to be replaced to ensure the continued safe and efficient operation of the PV system.