Custom DC Combiner Boxes for PV Systems
Project-specific custom DC combiner for commercial and utility-scale photovoltaic systems up to 1,500 V DC.
Typical Applications of Q3 PV Generator Junction Boxes
No off-the-shelf products: custom-engineered DC combiner boxes and PV string combiner solutions for commercial, industrial and utility-scale photovoltaic systems.
Protection concept, connection technology, enclosure design and monitoring functions are individually configured for each project – including standards-compliant design and documented testing.
Custom DC combiner boxes are particularly suitable for PV systems with complex layouts, high string counts or project-specific protection requirements.
Commercial and industrial PV systems with high string density
PV systems with complex roof layouts or multiple generator fields
Expandable PV projects for phased construction or utility-scale applications
Custom-Engineered DC Combiner Boxes for PV Systems
A DC combiner box – also referred to internationally as a PV string combiner box – bundles multiple PV strings per MPPT and integrates project-specific protection, disconnect and monitoring functions.
Unlike standard off-the-shelf string combiner boxes, every Q3 DC combiner box is individually engineered and precisely matched to the specific PV system design.
Q3 is not a catalogue supplier – but an engineering partner for DC connection technology.
Q3 DC combiner boxes are designed project-by-project and configured according to string count, system voltage, protection concept and monitoring requirements.
Whether standard PV string combiner boxes or complex DC combiner solutions with integrated protection and disconnect functions – every system is individually engineered, manufactured and electrically tested.
The focus is on straightforward integration, clearly defined configurations and cost-efficient implementation while maintaining standards-compliant system design.
Project-Specific Design of DC Combiner Box Solutions
Our custom-engineered DC combiner boxes are individually designed according to the specific PV system layout – from commercial rooftop systems to utility-scale solar plants.
During system design, parameters such as string count, system voltage (up to 1,500 V DC), short-circuit currents (Isc), reverse current conditions, as well as the required protection and monitoring concept are taken into account.
Typical Design Parameters:
■ High string density per inverter
■ Parallel connection of multiple generator fields
■ Segmented roof and system structures
■ Integration into monitoring and control systems
■ Consideration of short-circuit and reverse currents
Protection and Safety Concepts for GAK and DC Combiner Solutions
A generator junction box or DC combiner is far more than just a simple string collection box.
It performs central protection, isolation, and monitoring functions within the PV generator side – tailored to the number of strings, system voltage, and reverse current conditions.
Typical protection and safety functions:
Monitoring options for PV string boxes and DC combiners
Depending on the project requirements, the following functions can be integrated:
The monitoring functions described here are intended for status and current monitoring on string or component level.
For applications requiring active fault discrimination, automatic string shutdown or advanced analysis functions (e.g. identification of faulty strings during operation), we recommend the DC Combiner Super Multi Box with integrated PV string fault discriminator.
This means the custom-built DC combiner box remains the flexible solution for conventional monitoring and protection requirements, while the Super Multi Box has been specifically developed for intelligent fault detection and operational optimisation in utility-scale PV systems.
Which PV Systems Are Custom DC Combiner Boxes Suitable For?
Commercial and logistics rooftop PV systems
Industrial PV systems with complex roof structures
Ground-mounted PV systems | Agri-PV
Utility-scale solar power plants
High string densities per MPPT tracker
Projects with customised protection or grounding concepts
Custom-engineered DC combiner boxes – internationally often referred to as DC combiner boxes or PV string combiner boxes – bundle multiple PV strings per MPPT tracker in a standards-compliant way and integrate project-specific protection, isolation and monitoring functions.
Whether commercial rooftop PV systems, industrial installations or utility-scale solar plants:
Q3 DC combiner solutions are precisely designed according to string count, system voltage up to 1,500 V DC, short-circuit currents (Isc) and reverse current conditions. Compared to standardised solutions, this results in a DC connection box that:
■ is technically dimensioned with precision
■ avoids unnecessary oversizing
■ can be integrated in a standards-compliant manner
■ is designed for long-term operational reliability and serviceability
This makes the custom-engineered DC combiner box the ideal solution for demanding PV systems with high string density, special grounding or protection concepts, and complex generator structures.
Which DC Combiner Solution Fits My Project?
Custom DC Combiner Box
Project-Specific Solution
Custom-engineered DC combiner box for PV systems up to 1,500 V DC – ideal for demanding commercial, industrial and utility-scale solar projects.
LITE DC Combiner
Standard Solution
Standardised PV string combiner box for 1 | 2 | 3 MPPT systems with integrated surge protection – designed for projects with clearly defined standard requirements.
Super Multi Box
Intelligente DC-Combiner
Smart DC combiner with active fault detection – developed for utility-scale PV systems with advanced monitoring and performance optimisation requirements.
Engineering, Manufacturing and Testing in Germany
Every Q3 custom DC combiner box is individually engineered, manufactured and electrically tested – entirely at our production site in Germany.
Project Inquiry – DC Connection Technology | Custom DC Combiner Boxes
Would you like to configure a DC combiner box for your PV project, review technical details or define the optimal string and protection concept for your PV system?
Using the following inquiry form, we collect all relevant project data in a structured and traceable way – from string count through to the required monitoring integration.
You are welcome to upload data sheets, single-line diagrams, string layouts, Isc values, grounding concepts or protection concepts directly with your inquiry.
Based on this information, you will receive a project-specific DC combiner solution or an individually configured DC combiner box. If clarification is required, we will coordinate the details directly with you.
Project Inquiry – Custom DC Combiner Boxes
Inquiry form for the project-specific configuration of your custom DC combiner box including a tailored quotation.
Technical Documentation – DC Connection Technology
Data sheets, certificates and technical documentation for our complete DC connection technology portfolio including LITE DC Combiner and Super Multi Box.
DC Combiner Super Multi Box
Intelligent DC combiner with active PV string fault discrimination, automatic shutdown of faulty strings and integrated individual string monitoring.
LITE DC Combiner Standard Solution
Pre-configured DC combiner boxes for recurring PV system concepts – cost-efficient standard solutions with integrated surge protection concepts.