Solution for string combiners


Ground-mounted photovoltaics system  

Ground-mounted photovoltaics system

  • Planners and system operators face the challenge of optimizing the planned system yield and system availability.
  • Thanks to string combiner boxes from Phoenix Contact, you have the certainty of using a tested and therefore safe solution.
  • Ease of installation and simple integration into the infrastructure of the system are further positive aspects.


A survey in Photon magazine showed that experts judge 70% of German photovoltaics systems to be lacking. Due to assembly errors, the forecasted yield and therefore the return on investment of a photovoltaics system will be achieved later than anticipated. The expected repayment by means of feed-in compensation fails to materialize at the moment.

Employees in customer conversation  

The correct design of the string combiner box is the crucial factor

With its functions, namely connecting, measuring, and protecting, the string combiner box (SCB) is the decisive element with regard to a more cost effective design and the long-term availability of the photovoltaics plant. The SCB, however, is frequently only selected based on the cost. Quality and a long service life play a minor role.

For safer and higher-quality combiner boxes, planners and installation engineers must consider standard-compliant products. Switching device standard EN 61439, which describes the design, the selection of components, and the required tests, applies to the SCB. The standard also requires comprehensive documentation regarding the technical properties and operating conditions as well as for correct installation and maintenance. All information should be provided with the device as installation instructions, in the language of the country of the installation site.


Switchgear and controlgear assemblies from Phoenix Contact ensure error-free operation of photovoltaic systems. Thanks to optimally coordinated components and communication interfaces, you can connect the string combiner boxes to a higher-level park management system quickly and easily. A specialist team of experts from all the relevant divisions of the company jointly develop individual solutions together with you as the customer.

Preliminary development clarification with customers  

Control cabinet solutions for every customer requirement

During preliminary development clarification, all divisions work closely with our customers in order to implement the desired requirements in the best way possible. Specific challenges are identified at an early stage. This allows the development process to be handled in a target-oriented and efficient way.

Following completion of preliminary clarification, the design phase gets underway. This phase is completed with the creation of prototypes which undergo a specific testing procedure. The findings are used to further optimize the solution.

Testing procedures
Hotspots, for example, are detected with the aid of a temperature test. As a result, all components can be arranged in an optimal way. Failure due to thermal overload is therefore eliminated.

The prototypes are subjected to electrical and mechanical testing in our own test laboratories. The tests ensure that the solutions operate error-free in the intended installation environments.

Thermographic images of string combiner boxes compared  

Due to the temperature-optimized control cabinet design, failure due to thermal overload is eliminated

Following successful completion of all the relevant tests in the development phase, production is given the go-ahead. The components are manufactured in a one-piece flow system, in order to efficiently implement each individual steps. You can respond quickly and flexibly to changing designs and lot sizes. The information required for quality assurance can be viewed at a glance, thereby ensuring that production and the assembly process run smoothly.


In the production line, tools are used that allow all items to be produced with repeat accuracy. The use of screwdrivers with torque control ensures reliable and safe connections. The consistent quality of each individual SCB is therefore ensured. In the final production step, the final test takes place according to IEC 61439. A test report is then generated. All switchgear and controlgear assemblies as well as the components contained therein have serial numbers which allow them to be uniquely identified at any time.

SCB compact and SCB next generation  

Two intelligent solution concepts: SCB with string fuse outside the control box for 32 strings and SCB with standard string fuse for 16 strings

Your advantages

  • Application-oriented analysis and consultation
  • Optimum positioning of surge protection
  • Use of the best connection technologies and suitable components
  • Reduced costs and wiring effort.
  • A separate power supply unit in the field is not necessary
  • Space-saving installation, thanks to the compact design
  • Application-oriented analysis and consultation


DescriptionTypeOrder number
String combiner box for 32 strings with Inline fuseSOL-SC1-32-0-FI-VMC-T1-SD1-222403683
String combiner box for 16 strings with standard string fuseSOL-SC1-16-0-F-VM-T1-SD1-112403682
DescriptionTypeOrder number
String combiner box for 32 strings with Inline fuseSOL-SC1-32-0-FI-VMC-T1-SD1-22
String combiner box for 16 strings with standard string fuseSOL-SC1-16-0-F-VM-T1-SD1-11


Unit 15C, 906-930 Great South Road, Penrose
Auckland 1061
New Zealand

Phone: 0508 474 636
Toll Free (Local)
09 950 8495

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