Safety Improvement in Solar Power Station O&M: Fonrich DC Combiner Box Monitoring Solutions

I. Troubles of Ground-Mounted Solar Power Plants

A. Old Solar Plants: Getting More Troublesome Over Time

Currently, there are more than 60GW of ground-mounted solar plants in China that have been in operation for over five years. These "old buddies" are hiding a lot of issues:

• Component Aging: Parts exposed to wind and sun for years are seriously degraded.

• Communication Failures: Dropouts are common, causing monitoring and control to fail.

• Arc Faults: The most alarming issue is arc faults—80% of solar fires are caused by these. Once a DC arc spreads, an entire array can be destroyed in less than 30 minutes!

Even worse, traditional combiner boxes can take hours to diagnose faults. The system stays down for extended periods, and the safety risks linger.

B. New Project Integration: Roadblocks Everywhere

With the rapid advancement of solar technology, intelligent  combiner box monitoring with monitoring features have become the standard. By 2025, it's estimated that 60% of combiner boxes will come equipped with smart monitoring and remote management, which should, in theory, save a lot of trouble.

However, when it comes to installation, problems arise:

• Different Communication Protocols: Different manufacturers use incompatible communication protocols, which don't work together.

• Messy Device Specifications: Device specifications are often inconsistent, and space inside combiner boxes is tight, making it difficult to fit everything.

• Incompatibility: Devices from different brands and models simply won't work together.

But Fonrich's combiner box monitoring module can solve these issues—regardless of the model, even if space is tight, it can adapt. It also significantly improves power plant management and operational efficiency.

II. Fonrich Monitoring Module: What Makes It So Powerful?

The module comes with an LCD screen, which displays real-time data and offers a wide range of functionalities:

• Monitors string current and voltage

• Measures combiner box temperature

• Sends alarms for breaker and surge protector status

• Detects arc faults and alarms

• Supports multiple Hall sensor specifications

• Can connect up to 32 cascading channels

• Includes RS485 communication interface

1. Real-Time Monitoring, No Compromise

   • Current and Voltage Monitoring: Using patented Hall sensors, it can measure any current, even large ones. It can monitor up to 32 strings at once, and any issues are immediately noticeable.

   • Temperature Monitoring: With built-in temperature sensors, it tracks the temperature of the combiner box, surge protectors, and breakers, ensuring nothing is overlooked.

   • Arc Fault Detection: It integrates AFCI (Arc Fault Circuit Interrupter) functionality. As soon as DC arcs appear, it detects and sends an alert, greatly reducing fire risk.

2. Effortless Operation and Maintenance, Thanks to Smart Features

   • Local Data Viewing and Remote Management: The LCD screen displays data in bar graphs, making diagnostics very intuitive. The RS485 Modbus-RTU and industrial-grade wireless communication ensure stable remote monitoring without connectivity issues.

   • Flexible Power Supply Design: It draws power directly from the PV strings, so as long as one string is still operating, the module will keep working. Even in extreme conditions, it won’t fail.

III. Technical Advantages: Why Is It So Impressive?

1. High Adaptability and Space Efficiency

   • Modular Design: It’s divided into a control box and sensors, making it compact enough to fit into any combiner box, even those from various brands with tight spaces. There’s no need to replace the entire old box.

   • Full Compatibility: It supports various communication protocols, including RS485 Modbus-RTU. During system upgrades, you won’t have to worry about incompatible protocols.

2. Reliable and Tough: No Fear of Harsh Environments

   • With over 10 years in the industry, Fonrich’s technology is homegrown and has long dominated the market.

   • The exterior is coated with protective resin, making it resistant to humidity (up to 95%) and extreme temperatures (from -40°C to 70°C), while still maintaining stable performance.

3. Strong Technological Foundation, Hundreds of Patents

   • Fonrich holds more than 200 patents. Core technologies like the AFCI algorithm are all self-developed.

   • It supports multiple alarm strategies and can connect to an automatic tripping mechanism, ensuring the system reacts quickly in case of issues.

This combination of Fonrich's monitoring modules and their advanced technology is an essential part of ensuring solar power plants are safer, more efficient, and easier to maintain. Whether for new installations or retrofitting old systems, this solution addresses all common challenges in solar energy management.

IV. Case Studies

Vietnam 257 MW Solar Project

Youtin 500 MW Combiner Box Project