String Combiner Box

1. Enclosure
• Material: Weatherproof and durable FRP/PC enclosure
• Protection Rating: IP65 or higher for protection against dust, water, and environmental elements.
• Dimensions: Customizable sizes to accommodate required components and installation specifications.
• Mounting: Wall-mounted or pole-mounted options available for flexible installation in various solar PV array configurations.

2. Input Terminals
• Rated Voltage: Compatible with the voltage rating of the solar PV array, typically ranging from 600V to 1500V DC.
• Input Strings: Configurable to accommodate multiple input strings of solar panels, with options for series and parallel connections.
• Input Capacity: Depending on the system design and capacity, SCBs may support input capacities ranging from 6 to 24 strings or more.

3. String Monitoring and Protection
• Monitoring Devices: Built-in monitoring devices such as string-level DC combiners, string current sensors, and voltage meters for real-time monitoring of string performance.
• Overcurrent Protection: Circuit breakers or fuses rated for DC operation to protect individual strings from overcurrent conditions and faults.
• Surge Protection: Integrated surge protection devices to safeguard against lightning strikes and transient voltage surges.

4. Busbars and Connectors
• Material: High-conductivity copper busbars for efficient and low-resistance power distribution.
• Rating: Rated for continuous operation at system voltage levels, typically ranging from 600V to 1500V DC.
• Connection Type: Bolted or compression-type connectors for secure and reliable connection of input strings and output cables.

5. Monitoring and Control
• Communication: Optional communication interfaces (e.g., RS485, Modbus, Ethernet) for remote monitoring and data logging of string-level performance metrics.
• Alarm Indication: Visual or audible alarms for fault detection, abnormal string performance, or system malfunctions.
• Remote Monitoring: Compatibility with external monitoring systems or SCADA for centralized monitoring and control of multiple SCBs within a solar PV installation.

6. Environmental Conditions
• Operating Temperature: -25°C to +60°C (may vary based on enclosure and component specifications) to withstand varying environmental conditions.
• Humidity: Operating humidity range of 5% to 95% RH (non-condensing) to ensure reliable operation in different climatic conditions.
• Altitude: Rated for operation at altitudes up to 2000 meters above sea level (may vary depending on design considerations).

7. Compliance and Certification
• Standards: Designed and manufactured in compliance with relevant international standards (e.g., IEC 61439, UL 1741).
• Certification: CE marking or equivalent certifications indicating compliance with safety and performance standards for solar PV equipment.

8. Accessories and Optional Features
• Temperature Sensors: Integrated temperature sensors for monitoring ambient temperature within the SCB enclosure.
• Remote Trip Facility: Remote trip functionality for circuit breakers to facilitate quick isolation of faulty strings during maintenance or troubleshooting.
• Lightning Arresters: Additional lightning arresters for enhanced protection against lightning-induced surges in areas prone to thunderstorms.
• Alarm Notifications: Configurable alarm notifications via email or SMS for immediate alerts on string faults, anomalies, or performance deviations.
• Integration: Open architecture design for seamless integration with third-party monitoring and control systems using standard communication protocols.
• In case of monitoring:
• Communication:
• Communication Protocols: Compatibility with industry-standard communication protocols such as Modbus RTU, Modbus TCP/IP, or RS485 for seamless integration with monitoring systems.
• Wireless Connectivity: Optional support for wireless communication protocols such as Zigbee or Bluetooth for remote monitoring and data transmission.
• Data Transmission Rate: High-speed data transmission capabilities to ensure real-time monitoring and response to changes in string performance.
• Data Acquisition:
• Voltage Measurement Range: Typically, compatible with DC voltages ranging from 0V to 1500V DC, suitable for various solar PV array configurations.
• Accuracy Range: ± 0.5%
• Current Measurement Range: Support for precise measurement of string currents ranging from a few milliamperes to several amperes.
• Temperature Measurement: Integrated temperature sensors for monitoring ambient temperature and solar panel temperatures.
• SPD status & DC switch status: Provision for integrating SPD status & DC switch status.
• Irradiance Measurement: Optional sensors for measuring solar irradiance levels to assess solar panel performance.

1. What is the difference between SCB & SMB?

SCB (String Combiner Box): An electrical device used in solar photovoltaic systems to combine the output of multiple solar panels (strings) into a single bus, which then connects to the solar inverter.

SMB (Smart Combiner Box): Similar to SCB but with added intelligence to enhance system supervision and performance.

2. Can we use SCB for String Inverter?

Yes, you can use an SCB for a string inverter, but the inverter should have a single MPPT (Maximum Power Point Tracking).