Solar Combiner Box – What it is and Why You Want One

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In the photovoltaic power generation system, the combiner box is a wiring device that guarantees the orderly connection and confluence function of photovoltaic modules. The device can ensure that the photovoltaic system is easy to cut off the circuit during maintenance and inspection, and reduce the scope of power outage when the photovoltaic system fails.

The combiner box means that the user can connect a certain number of photovoltaic cells with the same specifications in series to form a photovoltaic string, and then connect several photovoltaic strings in parallel to the photovoltaic combiner box. After converging in the photovoltaic combiner box, through the control It is used as a complete photovoltaic power generation system, which can be connected to the mains grid.

Solar Combiner Box

Combiner box composition


The box body with beautiful appearance, strong and durable, simple and convenient to install, and the protection level is above IP 65. It is waterproof and dustproof to meet the requirements of long-term outdoor use.

DC circuit breaker

The DC circuit breaker is the output control device of the entire combiner box, which is mainly used for the connect/cut off the circuit. Its working voltage is as high as DC 1000. Since the power generated by the solar module is direct current, it is easy to cause arcing when the circuit is broken. Therefore, the temperature and altitude derating coefficient should be fully considered when selecting the model, and a special photovoltaic DC circuit breaker must be selected.

DC fuse

When the module has reverse current, the photovoltaic special DC fuse can cut off the faulted string in time. It is installed with a special enclosed base to avoid current backflow between the strings and burning of the modules. When the current backflow occurs, the DC fuse quickly removes the faulty string from the system operation without affecting other normal working strings, and can safely protect the photovoltaic string and its conductors from the threat of reverse overload current.

Surge protector

Since the photovoltaic combiner box is installed in an outdoor environment, we must consider lightning protection for the combiner box. For this reason, we have connected in parallel in the DC output part of the combiner box. Once a lightning strike occurs, the surge protector will quickly discharge the excessive electric energy to ensure the stable output of electric energy and protect the combiner box from lightning damage.Combiner Boxes take multiple source circuits and combine them in a single output.They are usually found between the modules and the inverter. 

Solar Combiner Box

Customized solar combiner boxes:

  • Designed for a DC system voltage of 1000 V to 1500 V
  • Connection of the DC strings directly or via plug-in connector
  • String monitoring, arc-fault detection, rapid shutdown
  • Fuse protection on plus and minus side depending on module type
  • Surge protection device type I + II
  • Flexible number of DC inputs
  • Due to the large number of project-specific DC combiners, we will compile the technical data after jointly evaluating your requirements.