PV String Combiner Box

PV String Combiner Box for Solar Power Systems — Reliable DC Protection & Smart Monitoring Solution

DSY's PV String Combiner Box is a professional DC-side confluence protection device engineered for ground-mounted solar farms, commercial and industrial rooftop systems, and distributed grid-connected installations. Supporting rated DC voltages of 1000V and 1500V, with 2 to 24 converging branches and a single branch rated current of 15A to 30A, it delivers flexible capacity for projects of any scale. The enclosure meets IP54/IP65 protection ratings, complying with GB/T 19064 and IEC 62109 standards. Built by a manufacturer with 60+ patents and 200 employees, DSY combines technical depth with proven supply capability.

What Is a PV String Combiner Box and Why Does It Matter?

In any photovoltaic power plant, managing multiple string outputs efficiently is a core engineering challenge. A PV String Combiner Box aggregates DC inputs from individual solar strings into a single high-current output fed to the inverter — reducing cable complexity, cutting installation labor, and centralizing protection in one enclosure.

Beyond simple aggregation, it acts as a protection and monitoring hub. It integrates fuses, anti-reverse connection modules, and surge protection into one compact unit. This makes it a critical balance-of-system component for both utility-scale and commercial projects.

Key Product Features

Multi-Layer Safety Protection

The unit integrates overcurrent, short-circuit, and reverse-connection protection as standard. The enclosure features a door lock seal and reliable shell grounding, preventing unauthorized access and reducing operational risk.

Outdoor-Grade Durability

The cabinet is constructed from 304 stainless steel or flame-retardant ABS, designed to resist UV radiation, extreme temperatures, and rain erosion. This weatherproof construction ensures long service life in exposed outdoor environments without performance degradation.

Waterproof Terminal Design

Special photovoltaic waterproof terminals are used on every branch connection, ensuring both electrical reliability and sustained waterproofing under repeated exposure to moisture.

Modular and Scalable Architecture

The branch circuit design is modular. You can select 2 to 24 input circuits depending on your array size, and the configuration can be expanded to include DC voltage and current monitoring, fault location, and remote communication modules as your system grows.

Technical Specifications

Application Scenarios

Utility-Scale Ground-Mounted Solar Farms

Large ground arrays — especially those using 1500V architectures — demand enclosures that handle high current loads while surviving harsh desert or semi-arid field conditions. DSY's combiner box delivers the rated voltage range, IP65 sealing, and modular expansion needed for long-term utility deployment.

Commercial & Industrial Rooftop Systems

Space constraints and fire safety codes make protection quality critical on rooftop installations. The integrated overcurrent and short-circuit protection, combined with the reliable grounding design, supports safe and code-compliant C&I deployments.

Distributed Grid-Connected Installations

For distributed photovoltaic projects, flexibility matters most. The modular branch design allows you to scale from a small 2-string configuration up to 24 strings, adapting to varied project sizes without redesigning the protection infrastructure.

Quality Control and Compliance

Every unit is subject to strict quality inspection before shipment. Key validation steps include dielectric strength testing, temperature rise testing under full load, and IP-rating verification through water ingress and dust penetration procedures.

The enclosure materials undergo UV weathering evaluation to confirm resistance to irradiance degradation over time. Terminal torque consistency checks are performed to prevent loose connections — a leading cause of thermal issues in field-deployed PV systems.

DSY provides a full set of type test reports, TÜV/CCC certificates, and technical drawings with every order, giving procurement and engineering teams the documentation needed for project approvals and compliance verification.

Customization and Supply Advantages

Your project requirements may not fit a standard configuration — and that is exactly why DSY supports full OEM customization. Cabinet material, branch count, and functional modules can all be specified to your design.

Optional intelligent monitoring modules can be added to support DC current/voltage data collection, string-level fault location, and RS485-based remote communication. This transforms the unit from a passive protection device into an active monitoring node within your plant's O&M system.

With RMB 50.6 million registered capital, an in-house technical team of 40 engineers, and qualified supplier status with State Grid and China Southern Power Grid, DSY has the production capacity and technical credibility to support both standard and custom orders reliably.

Frequently Asked Questions

Q1: What is the difference between 1000V and 1500V configurations?

A: 1500V systems support longer strings and reduced wiring runs, lowering balance-of-system costs. The 1500V combiner box requires higher-rated components and greater creepage distances to prevent DC arcing safely.

Q2: What protection functions are built in as standard?

A: Every unit includes overcurrent, short-circuit, and reverse-connection protection. The door lock seal and grounded enclosure add a physical security layer against unauthorized operation.

Q3: What does IP65 protection mean in practice?

A: IP65 means the enclosure is fully dust-tight and protected against water jets from any direction — making it suitable for continuous outdoor exposure across ground and rooftop installations.

Q4: Can the branch count be changed after initial installation?

A: The modular design supports reconfiguration. You can discuss specific expansion requirements with the DSY technical team based on your existing cabinet dimensions and system layout.

Q5: What certifications and documents come with the product?

A: DSY provides type test reports, TÜV/CCC certificates, and technical drawings with each order to support your project approvals and quality audits.

Q6: Is remote monitoring available on this PV String Combiner Box?

A: Yes. Optional intelligent modules support DC data collection, fault location, and RS485 remote communication. This allows integration with plant-level SCADA or O&M monitoring platforms.

Get in Touch

Ready to configure the right PV String Combiner Box for your project? Contact our team at [email protected] for a technical consultation or custom quotation.