PV Combiner Box: Complete Guide to Components & Installation

First, what is the photovoltaic junction box?

PV Combiner Box (PV Combiner Box) is the key electrical equipment of solar power generation system, mainly used for centralized direct current of photovoltaic series, and provides overcurrent, lightning protection and other protection functions to ensure the safe and efficient operation of the power station.

Second, the composition of the photovoltaic junction box

Core components:

Input terminal: Connect multiple PV modules (for example, 6-16 PV modules, each supporting 10A-15A).

Fuses/circuit breakers: Protect each string from overcurrent damage (commonly DC1000V/20A specifications).

Lightning protection module: SPD surge protector (40kA discharge capacity).

Auxiliary parts:

Dc isolation switch: emergency cut off circuit.

Waterproof housing: IP65 protection grade, suitable for outdoor environment.

Third, installation and wiring steps

1. Preparation before installation:

Confirm the installation position (close to the photovoltaic array and away from direct sunlight).

Check the ground terminal of the container (ground resistance ≤4Ω).

2. Wiring process:

Group string input:

Connect the corresponding terminal by polarity (+/-) to ensure that the voltage of each terminal is consistent.

Secure the MC4 connector to prevent virtual heating.

Output end:

Connect to the DC input terminal of the inverter (cable cross-sectional area ≥4mm²).

Lightning protection grounding:

SPD ground cable (≥6mm²) Connects to the ground bar.

3. Power test:

Measure the open circuit voltage (match the inverter input range).

Check whether the intelligent monitoring data is transmitted properly.

4. Precautions

Safety specifications:

Wear insulation gloves during operation. Do not work with live.

If the DC side has a high voltage (600V to 1500V), you need to set a warning label.

Maintenance Suggestions:

Clean the box regularly and check the fuse status.

Test SPD module effectiveness before thunderstorm season.

Five, selection suggestions

Depending on the size of the power station:

Small household: 6-8 input, integrated basic protection function.

Industrial and commercial power station: 12-16, with intelligent monitoring and remote communication.

Choose TUV/IEC certified bus boxes, such as CNLonQcom series products, to ensure 25 years of long-term protection!

The photovoltaic junction box is the "safety hub" of the power station, and the correct installation and maintenance can significantly improve the power generation efficiency. If you need specific model recommendations or technical solutions, please feel free to consult CNLonQcom!