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Combiner box – from the rooftop to the GW project
The combiner box combines the PV strings, protects the DC side and safeguards the system. The HISbox® from HIS Technology is a modular electrical infrastructure platform for projects ranging from rooftop systems to gigawatt-scale utility PV plants.
The HISbox® – for every plant class
Every PV system places its own demands on its electrical infrastructure. Plant size, inverter topology and country-specific standards determine which PV combiner box solution is required – whether hundreds of strings in a utility-scale PV plant or increased safety requirements on industrial roofs. The HISbox® adapts – configured for each project where complexity demands it, standardised where it makes sense.
HISbox® – PV combiner box solutions at a glance
The HISbox is planned and manufactured for each project – tailored to plant size, grid requirements and individual project conditions. Engineering, manufacturing and testing come from a single source, compliant with IEC 61439 and other applicable standards.
DC combiner box – The DC combiner box combines several PV strings and provides DC-side protection – a core component in DC-side HISbox configurations.
DC combiner box in detailAC combiner box – For large-scale plants in the MW and GW range, the AC combiner box handles combining on the AC side.
AC combiner box in detailDC disconnector – The DC disconnector enables off-load disconnection of individual PV strings – for safe maintenance and standard-compliant emergency shutdown.
DC disconnector in detailDC surge protection – Protection against lightning strikes and transient overvoltage events – integrated as type 1 and type 2 arresters in every HISbox.
DC surge protection in detailFireman switch – Legally required rapid shutdown of the DC voltage – tested according to EN 60947-3, compatible with common PV safety requirements.
Fireman switch in detail
Depending on the application, the HISbox can be extended with monitoring systems, arc fault detection, insulation fault measurement systems and project-specific protection classes – from rooftop systems to GW-scale ground-mounted plants.
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Every plant has specific requirements. In a personal conversation, we will clarify which HISbox configuration suits your project
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What is a combiner box?
PV modules generate direct current. Each string supplies its own voltage and current. Without combining and protection, each string would have to be connected individually to the central inverter, which is technically complex and becomes uneconomical as the plant grows. The PV combiner box combines the strings, fuses, protects and monitors them. This creates a scalable, standard-compliant and easy-to-maintain DC infrastructure for every PV system.
What is a combiner box for photovoltaics used for?
Ground-mounted solar park: In large ground-mounted solar parks, the HISbox® DC Combiner routes hundreds of strings to central inverters. String monitoring detects underperformance and arcs at an early stage, reducing the risk of failures that can affect a considerable part of the plant at up to 4–5 MW per central inverter.
Commercial and industrial rooftop system (C&I): On commercial and industrial roofs, the combiner box for PV systems combines fusing, fireman switch and monitoring. The fireman switch is required by law because PV modules continue to generate electricity when exposed to light, even in the event of a fire, endangering emergency services. For this purpose, the HISbox® supports three shutdown modes: manual, automatic in the event of a power failure and temperature-controlled.
Hybrid plants (PV + battery storage): In hybrid plants, the combiner box has the same function as in pure PV systems. PV and battery interact at inverter and AC level; special hybrid functions are not required in the combiner box, and the same HISbox® configuration remains usable.
Floating PV: Floating solar plants place special demands on moisture resistance, corrosion protection and mechanical strength. For this, the HISbox® can be supplied with protection ratings up to IP65, is UV-resistant and operates reliably from -20 °C to +55 °C. HISkon+® ALU is certified for floating PV systems according to TÜV 2 PfG 2750.
Regulatory framework: The HISbox® is manufactured according to IEC 61439 / EN 61439-2. EN 60947-3 applies to switch-disconnectors and fireman switches, and VDE-AR-N 4105 / 4110 to grid connection in Germany. HIS Technology delivers to more than 60 countries and takes country-specific standards into account in engineering.
Why HIS Technology?
Engineering from a single source
We plan, manufacture and test in one process. We configure every HISbox® for each project: voltage level, protection components, communication, protection rating and enclosure material are individually tailored to the respective project. Every HISbox® leaves the factory tested and ready for immediate use, with protection rating up to IP65 and impact resistance IK08, UV-resistant and operationally reliable from -20 °C to +55 °C, up to 4,000 m above sea level.
International reach
60+ countries. 2,000+ customers. 6.5+ GW of components delivered per year – With our own subsidiaries in Germany, France, Spain, Turkey, Bosnia and Herzegovina, Poland and the Netherlands, we incorporate country-specific standards and grid connection requirements into engineering from the outset.
Scalable for every project
The HISbox® Residential covers 1000 V DC, up to 60 A and 1 to 12 MPPTs and is compatible with SMA, Huawei, SolarEdge, Sungrow and Fronius. The HISbox® Utility Scale is designed for 1500 V DC and high-current configurations up to 80 A per string. The GRP or polycarbonate enclosures are suitable for indoor and outdoor use and comply with IEC 61439 / EN 61439-2.
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Smart monitoring in combiner boxes
Detect problems at an early stage, optimize yields and reduce maintenance costs - intelligent combiner boxes (GAKs) are evolving from simple protection devices to the digital control center of modern PV systems. A development that is fundamentally changing the monitoring of solar parks.
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Safety first
In the solar industry, safety is paramount - especially when it comes to protecting human life. An often overlooked but crucial component is the fireman switch in the combiner box (GAK). It plays a key role in protecting emergency services and securing PV systems in the event of an emergency.
Enquire about a HISbox solution now and realise your project
Enquire nowHISbox® as part of the overall solution
Frequently asked questions about the combiner box
A DC combiner box is required for central inverter topologies. With string inverters it is not needed, although an AC combiner box can be useful. As a rule of thumb, the more strings, the more relevant the PV combiner box.
The HISbox® is manufactured according to IEC 61439 / EN 61439-2. EN 60947-3 applies to switch-disconnectors and fireman switches, and VDE-AR-N 4105 / 4110 to grid connection in Germany. We take country-specific standards into account in engineering.
The HISbox® is configured entirely for each project. Voltage level, number of MPPTs and strings, protection components, communication, protection rating and enclosure material are individually tailored. Configuration takes place via a structured enquiry process with direct engineering support.
The HISbox® covers all plant classes – from combiner boxes for small photovoltaic systems with 1000 V DC and commercial and industrial plants in the kWp to MWp range to GW-scale ground-mounted solar parks with 1500 V DC and high-current configurations up to 80 A per string.
The HISbox® is the combiner box for PV systems and provides combining, fusing and protection. HISkon+® is a pre-assembled DC cable harness that connects modules and combiner boxes. Both products are developed as a system and matched to each other. This reduces installation effort and interface risks.
We deliver to more than 60 countries and have our own subsidiaries in Germany, France, Spain, Turkey, Bosnia and Herzegovina, Poland and the Netherlands. We take country-specific standards and grid connection requirements into account in engineering. Multilingual support is available.