What is a photovoltaic combiner box? The photovoltaic combiner box is a wiring device that ensures the orderly connection and convergence function of photovoltaic modules in the photovoltaic power generation system. It means that the user can connect a certain number of photovoltaic cells of the same specification in series to form a photovoltaic string, and then connect several photovoltaic strings in parallel to the photovoltaic combiner box. The inverter and AC power distribution cabinet are used together to form a complete photovoltaic power generation system to realize the grid connection of the mains.

PV combiner box components

1. Cabinet

The box body is generally made of steel plate spray, stainless steel, engineering plastic, etc., with beautiful appearance, sturdy and durable, simple and convenient installation, protection grade IP54 or above, waterproof and dustproof, and meets the requirements of long-term outdoor use.

2. DC circuit breaker

The DC circuit breaker is the output control device of the entire combiner box, and is mainly used for circuit opening and closing. Its working voltage is up to DC1000V. Since the power generated by the solar module is direct current, it is easy to generate arcs when the circuit is disconnected. Therefore, the temperature and altitude derating factors should be fully considered when selecting models, and a dedicated photovoltaic DC circuit breaker must be selected.

3. DC fuse

When the reverse current occurs in the module, the photovoltaic special DC fuse can cut off the faulty string in time. The rated working voltage can reach DC1000V, and the rated current is generally 15A (crystalline silicon components). The DC fuses used in photovoltaic modules are special fuses designed for photovoltaic systems. It is installed with a special closed base to avoid current backflow between strings and module burnout. When the current reverses, the DC fuse quickly removes the faulty string from the system operation without affecting other normal working strings, and can safely protect the PV string and its conductors from reverse overload current. threaten.

4. Anti-reflection diode

In a junction box, the role of a diode is different from that in a component junction box. The diodes in the junction box mainly provide the freewheeling channel when the battery is shielded, and the diodes in the bus box mainly prevent the circulation between the group and the string.

5. Data acquisition module

In order to monitor the working state of the entire power station, a data acquisition module is generally added to the primary junction box. Using Hall current sensor and single-chip technology, the current signal (analog) of each photovoltaic array is sampled, converted into digital signal through A/D, and then converted into standard RS-485 digital signal output, which is convenient for users to grasp the entire power station in real time working status.

6. DC high voltage surge protection device

DC high voltage surge protection device is a special lightning protection product for photovoltaic power generation system, with dual self-protection functions of overheating and overcurrent; it adopts modular design, can be replaced, and has a deterioration display window; remote monitoring can be achieved through remote alarm device and data acquisition module accomplish.

7. Human-machine interface

The data acquisition unit is equipped with a man-machine interface, through which the real-time working status of the equipment can be viewed, the real-time working status of the equipment can be realized through the keyboard, and the local setting of the equipment parameters can be realized through the keyboard. What is a photovoltaic junction box? The PV junction box components are as above. Using the photovoltaic junction box, the user can connect a certain number of photovoltaic modules of the same specification in series to form a photovoltaic module string according to the DC voltage range input by the inverter, and then connect several strings to the photovoltaic array lightning protection junction box. The output after the circuit breaker is convenient for subsequent inverter access.