What Is The Purpose of Solar DC Combiner Boxes?


Why would you want to add another component to your already expensive solar power system? You might want to avoid skipping the solar combiner box from a reputable manufacturer. The combiner box is relatively inexpensive in comparison to all of the other expensive equipment, but it provides numerous additional benefits to your system.

Incoming energy is combined by solar combiner boxes into a single main feed, which is then distributed to a solar inverter. Labor and material costs are reduced as a result of wire reductions. Solar combiner boxes include overcurrent and overvoltage protection to improve inverter protection and dependability.

Let's look at what a combiner box is and what it does in your solar system. 



The DC combiner boxes in ground-mounted solar power plants are distributed throughout the PV module array, whereas the inverters are located in a single location. This results in minimal power loss on the AC side and short cable runs between the inverters and the transformer, allowing us to fully utilize our inverters' high efficiency. This type of construction allows for the avoidance of AC lines on the roofs of commercial and industrial PV installations.

The available configuration options allow you to tailor the combiner boxes to your needs or the installation requirements of the location where they will be used. For example, it is extremely feasible to incorporate the requirement for arc fault detection as well as a quick shutdown capability or a "fireman's switch" for remote system disengagement Those who select bifacial PV modules will find DC combiners especially useful: they allow the user to apply the appropriate fuses of at least 25 amps to offset the increased currents.


The function of the combiner box is to combine the output of multiple solar strings. Each string conductor lands on a fuse terminal, and the output of the fused inputs is merged onto a single wire that connects the box to the inverter. Although this is the most basic type of combiner box, once installed in your solar project, it usually comes with additional functions. Disconnect switches, monitoring equipment, and remote rapid shutdown devices are examples of additional equipment.

It is similar to a junction box, which is an electrical enclosure that securely connects multiple wires and cables through various entrance points. A solar combiner box combines the output of multiple strings of PV modules for connection to the inverter. It usually houses the input overcurrent protection fuse assemblies for several strings. The number of strings could range between three and fifty-two. 

String monitoring hardware, surge protection devices, and DC disconnects are examples of additional components that can be included in a solar combiner box. Choosing the best solar combiner box necessitates a thorough understanding of the task site as well as the level of difficulty. You should also understand how the other components interact with the combiner.


Choosing the best solar combiner box frequently comes down to price and availability. If you're installing your box in a residential building, an off-the-shelf solution might be best. They frequently offer a variety of possible configurations. The customization feature saves you time and money by preventing you from making unnecessary purchases. Despite the fact that the enclosure is typically one of the more expensive components of a solar combiner box, the box needs to provide long-term service.

Most solar combiner boxes are housed outside in enclosures. You should think about the weather. In areas with high humidity or frequent fluctuations in humidity, it's a good idea to include a breather or condensation vent. This will allow the pressure in the enclosure to be equalized. Water molecules are kept out of the solar combiner box as well.



It frequently houses the input overcurrent protection fuse assembly for many strings. There could be anywhere from three to 52 strings. A solar combiner box can also house auxiliary components such as string monitoring hardware, surge protection, and DC disconnects.

Examples include:

  • When the system contains more than three PV module strings.

  • I'd like to improve the inverter's protection.

  • In order to achieve a quick shutdown in the event of sudden changes in current.

  • People only need to be aware of the network's complexity and put safeguards in place.

  • A solar combiner box is also simple to install, and because they are so durable, there will be no need to replace them.

  • By reducing the number of wires connected to the inverter, the use of a solar combiner box has the potential to save money.

  • The combiner box reduces the number of connections to the fuse terminals while also making it easier to understand and locate the necessary wires.


Installing your solar combiner box on a north-facing wall with some shade is ideal. This reduces the amount of direct sunlight it receives. As you might expect, prolonged sun exposure can raise the temperature of the internal combiner. As a result, the effectiveness and lifespan of the box's components may be compromised. It's also worth noting that the effectiveness of the box may be affected by the efficiency of the power distribution box manufacturer.

Larger enclosures have more air volume and surface area. This helps to keep the interior components cool. Larger enclosures facilitate field wiring by providing more space to work in during installation and maintenance.

The combiner box should be located between the solar panels and the inverter. When properly positioned in the array, it can reduce power loss. The significance of location in pricing cannot be overstated. Because a combiner in an inconvenient location may result in higher DC BOS expenses due to voltage and power losses, placement is critical. It's only a few cents per watt, but getting it right is critical.


Solar energy has long dominated the world. However, this concept is slowly being adopted by the entire world in order to successfully use renewable energy sources such as solar energy, and solar combiner boxes can boost the effectiveness of your solar system and protect the inverter from excessive voltage or current.

There are also dangers to your safety. What if there is a power outage, for example? The solar combiner box from Aswich assists us in dealing with the situation. For high-quality products, contact Aswich.

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