In modern photovoltaic (PV) power plants, cables play a critical role in power transmission. PV systems involve both DC and AC sides with complex power distribution, demanding strict requirements for heat resistance, moisture resistance, UV resistance, and mechanical strength. Improper cable selection can reduce power generation efficiency, increase system safety risks, and even affect the overall lifespan of the PV plant.
Among various cable types, RHW-2, XHHW-2, and UL 4703 cables have been widely adopted for their excellent performance and reliability. This article provides a detailed comparison of these three cable types in terms of structure, performance, standards, and application scenarios. It also introduces the products and service solutions provided by Dongguan Greater Wire & Cable Co., Ltd., helping customers quickly find the most suitable cable solution for their projects.
Characteristics of Commonly Used Cables in PV Plants
Cables used in PV power plants need to meet the following key requirements:
- High Temperature Resistance: The surface temperature of PV modules under direct sunlight can reach 90℃ or higher, and the temperature inside inverters and combiner boxes may rise quickly. Cables must operate stably for extended periods without insulation aging or performance degradation.
- Moisture Resistance: Cables are often buried underground or exposed to humid air, and must maintain stable insulation resistance to prevent short circuits or leakage.
- UV Resistance: Outdoor cables are prone to aging and cracking from UV exposure. The jacket material must provide strong UV protection to ensure a service life exceeding 25 years.
- Mechanical Strength: Cables may undergo stretching, bending, or compression during installation and transportation, so flexibility and mechanical strength are essential.
- Electrical Safety: Current carrying capacity, voltage rating, and dielectric strength must meet system design requirements to ensure safe operation of both DC and AC circuits.
RHW-2 Cable Features and Applications
RHW-2 cable is a commonly used high-temperature and moisture-resistant cable in the US market, widely applied in buried wiring and large-scale energy systems in PV plants.
- Construction: Copper or aluminum conductor with cross-linked polyethylene (XLPE) insulation and weather-resistant jacket, providing excellent electrical performance and environmental adaptability.
- Performance: Rated temperature 90℃, suitable for damp, dry, and buried environments, with excellent UV resistance.
- Application Scenarios:
1.Buried main and branch lines in ground-mounted PV plants
2.Wiring for inverters and combiner boxes
3.Outdoor support structures or conduit routing
RHW-2 cables are known for high reliability and long service life, making them widely used in large-scale PV projects.
XHHW-2 Cable Features and Applications
XHHW-2 cable offers similar performance to RHW-2 but provides higher flexibility and easier installation.
- Construction: Copper or aluminum conductor with XLPE insulation, soft and heat-resistant.
- Performance: Rated temperature 90℃, moisture-resistant, UV-resistant, and highly flexible for conduit or rooftop installations.
- Application Scenarios:
1.AC side wiring in PV systems
2.Rooftop PV installations
3.Conduits or complex routing requiring flexible cables
XHHW-2 cables are the preferred choice for rooftop and distributed PV systems due to their flexibility and cost efficiency.
UL 4703 Photovoltaic Cable Features and Applications
UL 4703 cable is specifically designed for the DC side of PV systems, ensuring safe and reliable power transmission between modules.
- Construction: Tinned copper conductor with UV- and weather-resistant insulation and jacket, suitable for long-term outdoor exposure.
- Performance: Rated temperature up to 90℃ or higher, UV-resistant, moisture-resistant, and aging-resistant.
- Application Scenarios:
1.PV module string connections
2.DC bus wiring
3.Combiner box connections
UL 4703 cables are irreplaceable on the DC side, ensuring long-term stability of PV systems.
Performance Comparison of RHW-2, XHHW-2, and UL 4703 Cables
| Feature / Cable Type | RHW-2 | XHHW-2 | UL 4703 |
|---|---|---|---|
| Rated Temperature | 90℃ | 90℃ | 90-125℃ |
| Moisture Resistance | Excellent | Excellent | Excellent |
| UV Resistance | High | High | High |
| Flexibility | Medium | High | Medium |
| Suitable Environment | Buried, ground | Rooftop, conduit | Module side, DC connections |
| Typical Applications | Inverter wiring, buried lines | Rooftop wiring, AC side | PV module string, combiner box |
| Standard Certification | UL | UL | UL 4703 |
| Conductor Material | Copper/Aluminum | Copper/Aluminum | Tinned Copper |
| Jacket Material | XLPE / Weather-resistant | XLPE / Weather-resistant | PV-grade weather-resistant |
| Typical Project Type | Ground-mounted PV | Rooftop distributed PV | PV module string |
| Installation Convenience | Medium | High | Medium |
Table Notes: Added conductor type, jacket material, project type, and installation convenience for quick reference.
Application Case Studies in PV Plants
Ground-Mounted Large PV Plants
- Recommended Cable: RHW-2
- Applications: Buried main lines, inverter wiring
- Case Study: A large-scale ground-mounted PV plant in North America used RHW-2 for buried lines over 20 km. The system has operated for over 10 years without failure, proving its stability and durability.
Rooftop Distributed PV Systems
- Recommended Cable: XHHW-2
- Applications: Rooftop support structure wiring, AC side connections
- Case Study: A commercial rooftop PV project used XHHW-2, allowing easy conduit installation and reducing construction time by 30%, improving efficiency.
PV Energy Storage Systems
- Recommended Cable: UL 4703
- Applications: Module-side DC connections, combiner boxes
- Case Study: A PV energy storage project in South America used UL 4703, providing excellent UV and moisture resistance suitable for tropical environments, ensuring long-term system stability.
Advantages of Our Cables
Wide Range of Products
We specialize in producing UL-certified cables, including THHN, THW, MC Cable, AC Cable, meeting diverse needs of PV systems and building electrical projects.
Fully Compliant with the American Market
All cables are UL-certified, widely used in the US, Canada, and Latin American PV projects.
Complete Specifications
We provide full coverage of standard models, supporting different voltage levels, conductor sizes, and application scenarios, offering a one-stop solution.
Strong Delivery Capability
Fast delivery is available for both small sample orders and large-scale project procurement.
Technical Expertise and Service Support
We offer professional technical guidance from cable selection to construction support and after-sales service, ensuring smooth project implementation.
Extensive International Cooperation
With years of manufacturing and export experience, we have partners worldwide, including EPC contractors, PV module manufacturers, and engineering firms.
UL Certification Guarantee
All cables are UL-certified, ensuring compliance with international safety and performance standards.
Customization Services
We provide customization for materials, specifications, lengths, colors, performance, labeling, and packaging to meet special 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