With the global expansion of renewable energy, photovoltaic (PV) systems play an increasingly important role in commercial, industrial, and residential power supply. The stability of a PV system relies not only on the quality of the solar modules but also on the reliability of the cabling system.
Hot and humid environments, such as tropical regions, coastal areas, or underground moist ducts, can cause insulation aging, jacket cracking, and conductor corrosion, affecting system efficiency and safety.
Among various cable types, RHW-2 cables stand out for their excellent heat, moisture, and weather resistance, making them an ideal choice for PV systems. This article will detail the performance advantages of RHW-2 cables, compare them with other common cables, present specifications and real-world applications, and showcase our expertise in UL-certified cable manufacturing.
The Role of RHW-2 Cable in Photovoltaic Systems
RHW-2 stands for Reinforced Heat and Water-Resistant Cable, Type 2, designed to operate reliably in high-temperature and high-humidity environments. Its main structure includes:
- Conductor: Made of high-purity oxygen-free copper or tinned copper, providing low resistance, high conductivity, and flexibility.
- Insulation Layer: Constructed from heat- and moisture-resistant thermoplastic or thermoset materials, capable of continuous operation at 90°C and short-term exposure up to 105°C.
- Jacket Layer: Made of UV-resistant, ozone-resistant, and corrosion-resistant PVC or vinyl materials, ensuring long-term outdoor or moist-environment performance.
In PV systems, RHW-2 cables are used for connections between solar modules and inverters, inside combiner boxes, and for main trunk lines. Their superior heat and moisture resistance ensures safe power transmission under continuous sunlight, rain, or high humidity.
How RHW-2 Cables Handle Hot and Humid Conditions
-
Heat Resistance
PV systems are often exposed to direct sunlight, with ambient temperatures exceeding 45°C. The insulation of RHW-2 cables is specially formulated to remain stable at continuous 90°C operation. Compared with standard THW cables, RHW-2 maintains insulation integrity, prevents conductor oxidation, and avoids resistance increases even in extreme heat.
-
Moisture Resistance
Moisture can lead to insulation hydrolysis and conductor corrosion, common causes of PV system failures. RHW-2's water-resistant insulation and jacket minimize water absorption, ensuring that cables remain safe from short circuits or leakage even when buried underground or installed in coastal humid environments.
-
UV and Weather Resistance
Outdoor PV systems require protection against UV radiation, rain, and salt corrosion. RHW-2's jacket material is UV-stabilized, preventing cracking and aging under prolonged sun exposure and ensuring long-term reliability.
Comparison with Other Common Cables
To highlight RHW-2's advantages, we compare it with THW cables. While THW cables are more economical, they have limitations in hot and humid conditions.
| Performance Metric | RHW-2 | THW |
|---|---|---|
| Rated Temperature | 90°C continuous, 105°C short-term | 75°C continuous, 90°C short-term |
| Moisture Resistance | Excellent, suitable for prolonged water exposure | Average, prone to swelling and water absorption |
| UV Resistance | High, suitable for outdoor exposure | Medium, requires additional jacket |
| Service Life | 25+ years | 15–20 years |
| PV System Suitability | High | Medium, needs extra protection |
| Safety | UL-certified, prevents short circuit and leakage | UL-certified, but prone to aging in humid conditions |
The table shows that RHW-2 outperforms THW in temperature tolerance, moisture resistance, UV protection, and safety, making it the preferred choice for PV applications in harsh environments.
RHW-2 Cable Specifications and Application Scenarios
RHW-2 cables come in a variety of specifications to meet diverse PV system requirements. Common specifications are shown below:
| Model (AWG) | Conductor Area (mm²) | Rated Voltage | Application Scenario |
|---|---|---|---|
| 10 AWG | 5.26 | 600V | Short connections between rooftop modules and combiner box |
| 8 AWG | 8.37 | 600V | Main trunk lines for medium-sized PV arrays |
| 6 AWG | 13.3 | 600V | Large-scale ground-mounted PV main lines |
| 4 AWG | 21.2 | 600V | Trunk lines from combiner boxes to inverters |
| 2 AWG | 33.6 | 600V | High-power inverter to distribution cabinet |
Applications by Scenario
1.Rooftop PV Systems: 10–8 AWG RHW-2 cables are preferred for their flexibility and easy installation in limited space.
2.Ground-Mounted PV Farms: 6–4 AWG cables are used for main trunk lines to ensure low voltage drop and high current capacity.
3.Coastal or High-Humidity Areas: All RHW-2 cables use corrosion-resistant jackets for long-term performance.
4.Underground Installations: RHW-2 can be directly buried or run through conduits, ensuring safe power transmission.
Additional Advantages of RHW-2 in PV Systems
-
Safety
RHW-2 cables are UL-certified and meet strict North and South American standards. Their superior insulation and jacket prevent short circuits, leakage, and fire hazards, improving overall PV system safety.
-
Cost Efficiency
Although the initial investment is slightly higher, RHW-2 cables' durability reduces maintenance costs and replacement frequency. For large PV projects, this results in significant long-term savings.
-
Environmental Adaptability
RHW-2 cables perform reliably in extreme conditions, including high temperature, humidity, salt spray, and UV exposure, making them ideal for tropical, coastal, or underground PV environments.
Our Product Advantages
1.Wide Product Range
We specialize in UL-certified wires and cables, including THHN, THW, MC Cable, and AC Cable, meeting diverse PV system needs. Customers can refer to our UL Wire catalog for more information.
2.Compliance with American Standards
All products are UL-certified, meeting stringent safety and performance requirements for the Americas.
3.Comprehensive Specifications
Our offerings range from 10 AWG to 2/0 AWG, covering rooftop systems to large-scale PV farms.
4.Fast Delivery
With complete supply chain and manufacturing capabilities, we support both small and large batch orders to ensure project timelines are met.
5.Professional Technical Support
Full pre-sales and after-sales support, including design recommendations, cable selection, and installation guidance, ensures smooth deployment.
6.International Cooperation Experience
Years of manufacturing and export experience have allowed us to establish stable partnerships with global PV projects and distributors.
7.UL Certification Assurance
All products are rigorously tested and UL-certified for long-term operational safety.
8.Customization Services
We provide full customization, including materials, specifications, length, color, performance, labeling, and packaging, catering to unique project requirements.
Company Information
Dongguan Greater Wire & Cable Co., Ltd.
- Tel/WhatsApp/Wechat: +86 135 1078 4550 / +86 136 6257 9592
- Email: manager01@greaterwire.com
RHW-2 cables combine heat, moisture, and weather resistance with a wide range of specifications, making them ideal for PV systems operating in hot and humid environments. With our expertise and global supply experience, customers receive reliable, flexible, and high-quality cable solutions that ensure PV systems operate efficiently and safely for years.