How to Choose a PV Solar Combiner Box

In a photovoltaic (PV) power generation system, the combiner box is a crucial component. Choosing the right PV combiner box can not only improve system efficiency but also ensure the safe operation of the system. Here are the key factors to consider when selecting a PV combiner box.

1. Selection of Input and Output Circuits

The number of input and output circuits of a solar combiner box depends on the scale and design of the PV array:

•n Inputs and m Outputs: Typically, combiner boxes come in configurations such as 2 in 1 out, 4 in 1 out, 6 in 1 out, 8 in 1 out, and so on. The number of inputs refers to the number of PV module strings, and the number of outputs refers to the number of outputs to the inverter. Choose the appropriate configuration based on the scale of the PV array. For example, a larger PV system may require an 8 input 1 output combiner box.

2. Required Components

A PV combiner box usually includes the following components:

•DC Circuit Breaker(MCB、MCCB): Used to protect the circuit, preventing overload and short circuit.

•Fuse: Provides overcurrent protection to ensure system safety.

•Surge Protector: Protects the system from lightning strikes and voltage surges.

•Monitoring Module: Used for real-time monitoring of current, voltage, and other parameters to ensure the normal operation of the system.

•Grounding Terminal: Ensures the safe grounding of the system.

3. Voltage and Current Requirements

When selecting a PV solar combiner box, you need to determine the appropriate model based on the system's rated voltage and current:

•Voltage: The rated voltage of a PV combiner box is usually 500VDC, 1000VDC, or 1500VDC. Choose the appropriate combiner box based on the voltage specifications of the PV modules and inverter.

•Current: The rated current of the combiner box needs to be determined based on the output current of the PV modules. The current of a single string is generally 15A, and common total current specifications are 32A, 63A, 125A, or even higher.

4. Enclosure Material

The material of the PV combiner box enclosure significantly affects its performance and lifespan:

•Material: High-quality combiner boxes typically use ABS+PC or metal materials, which have good weather resistance and corrosion resistance.

•Protection Level: The enclosure of the combiner box should have a high protection level, such as IP65 or IP66, to ensure long-term stable operation in outdoor environments.

•Flame Retardancy: The enclosure material should have good flame retardant properties to ensure that it does not cause a fire in the event of a fault.

Choosing the right PV combiner box is a crucial step to ensure the efficient and safe operation of a PV power generation system. It is necessary to consider the number of input and output circuits, required components, and enclosure material based on the scale of the PV system, voltage, and current requirements, as well as environmental conditions. CNLonQcom provides a variety of specifications and configurations of PV combiner boxes to meet the needs of different customers and ensure the optimal performance of PV systems.