Inverters for photovoltaic systems
The inverter is the central component of every photovoltaic system – both technically and functionally. It converts the direct current (DC) generated by the PV modules into grid-compliant alternating current (AC) while also performing essential control, monitoring and safety functions.
No other component has as much influence on system performance, efficiency and operational reliability as the inverter. Modern devices not only manage energy conversion but also support advanced energy management – including grid interaction, battery storage integration and smart energy systems.
As a specialist in in-roof photovoltaics and building-integrated PV (BIPV), deSonna GmbH offers a carefully selected portfolio of high-quality inverters from leading manufacturers, optimally matched to Solrif® systems and the requirements of modern residential and commercial energy projects.
APsystems DC connector cap (MC4) – Protective cap for unused DC connectors
The APsystems DC connector cap (MC4) reliably protects unused DC sockets in PV installations from moisture, dust and dirt. It simply slots onto the open MC4 socket, providing a secure, weatherproof seal – ideal for clean, long-lasting solar system installations.More informationWhy a DC connector cap is importantExposed MC4 sockets can corrode or become contaminated over time. This compromises electrical safety and can lead to power losses. The APsystems DC connector cap prevents exactly that: it reliably seals the socket and protects against environmental influences.Technical specificationsProtection rating: IP67 – fully dust-tight and protected against temporary submersionMaterial: Weather-resistant plastic (PV-SVK4) MC4-compatible: suitable for standard DC sockets in PV systemsApplications: PV modules, extension cables, inverter DC inputsDimensions as per technical drawingCap diameter: approx. 19 mmLength: approx. 28.3 mmEyelet: 3.2 mm (for optional securing) Advantages of the APsystems DC connector capReliably protects open MC4 sockets from external influencesHigh level of sealing thanks to integrated sealSimple, tool-free installationDurable material suitable for outdoor useApplicationsIdeal for installations where a DC connector is not in use – e.g. for modular extensions, maintenance work or open spare connections.The APsystems DC connector cap (MC4) provides reliable protection for unused DC sockets and is an essential accessory for durable and safe PV installations.
APsystems female connector for DC plug (MC4)
The APsystems socket cap for DC connectors (MC4) is an essential protective accessory for securely sealing unused MC4 connectors and providing reliable protection against environmental influences.More informationKey featuresProtects unused MC4 connectors from dust, moisture and dirtIncreases operational reliability and extends the service life of the PV installationRobust construction for long-term outdoor useEasy installation – simply plug in, lock into place, and you’re doneCompatible with all standard MC4 connectorsApplicationThe socket cap is used to securely cover an unused MC4 connector. Ideal for modular expansion of PV systems, for spare connections or for the temporary decommissioning of individual strings.Benefits for installers & operatorsProtects against corrosion and contact damagePrevents unwanted electrical contactHelps ensure compliance with safety-related installation standardsQuick to replace during future expansionsTechnical informationType: MC4 socket capApplication: Indoor & outdoorInstallation: Plug onto an unused MC4 connector
APsystems release mechanism for AC bus cables (5-core)
The APsystems release mechanism allows the connection between the micro-inverter and the 5-core AC bus cable to be disconnected safely and easily – ideal for installers and service calls.More informationWhat does the release tool do?The release tool has been specially developed for the APsystems 5-wire AC bus cable and enables quick, damage-free disconnection of the connectors. It ensures that installations or maintenance work can be carried out efficiently and safely.Features & BenefitsSafe release of the micro-inverter from the AC bus cableSpecially designed for 5-wire APsystems bus cablesPrevents damage to plugs and socketsFacilitates maintenance, replacement or expansion of the systemRobust construction made from durable PBT plasticCompatibilityThis tool is compatible with all APsystems 5-wire AC bus cable systems and latest-generation micro-inverters (e.g. QT2 series).Technical specificationsMaterial: PBT (high-quality, durable plastic)Colour: BlackItem number: 2353000002Product type: 5C Connector Unlock Tool
APsystems cover cap for the AC bus cable connector (Y-connector)
The APsystems cover cap for the Y-connector socket on the AC bus cable reliably protects unused connectors from moisture and dirt, ensuring a safe and long-lasting installation.More informationReliably protects unused Y-connectionsThe APsystems Y-Conn Cap is specifically designed to seal unused branches on the APsystems AC bus cable. It prevents the ingress of moisture, dust and other environmental factors, and contributes significantly to electrical safety and the longevity of the entire system.Key benefitsWatertight seal for unused Y-connection socketsProtects against the elements and increases system reliabilityEasy installation – quick fitting without toolsPrecisely fitted for APsystems AC bus cables (Y-connector)Robust construction for long-term outdoor useTechnical specificationsAPsystems part number: 2061702007 (Y-Conn Cap)Dimensions as per drawing (W x H): approx. 41.5 mm x 32.5 mmInner diameter at top: approx. 13 mmSide width: approx. 17.5 mmMaterial: UV-resistant plasticProtective function: Sealing of unused AC bus cable Y-connectionsApplicationThe cover cap is used to securely seal an open Y-branch of the APsystems three-phase AC bus cable. Ideal for installations with QT2 micro-inverters or other compatible APsystems three-phase components.NoteThe cover cap is suitable exclusively for APsystems Y-connector bus cables – not compatible with T-connectors or single-phase bus cables.
APsystems 2m DC extension cable (MC4)
The APsystems 2-metre DC extension cable provides a safe, robust and compatible connection for photovoltaic installations – ideal for extending or routing PV module cabling flexibly.More informationRobust, safe and reliableThe APsystems DC extension cable is fitted with a permanently attached MC4 connector and has been specially developed for use in solar installations. The high-quality construction ensures maximum safety and a long service life – even under demanding installation conditions.Fixed connection between cable and connector – prevents detachment and offers increased tensile strength.Tensile strength up to 100N (60 seconds) – ideal for installations subject to tensile loads or cable runs over longer distances.Precision manufacturing – pins are concentric, preventing incorrect insertion or reversed polarity.High compatibility – suitable for PV modules and micro-inverter systems with MC4 connectors.ApplicationsThe cable is suitable for:Extending PV module connectionsOptimised cable routing for micro-invertersRetrofits or system extensionsTechnical dataLength: 2 metresConnector type: MC4 compatibleTensile strength: 100N for 60 secondsItem number: 2310360214The DC extension cable is a reliable solution for professional PV installations and ensures safe and durable connections.
APsystems 40A AC connector (EN, 5-core, plug)
The APsystems 40A AC connector (EN, 5-core, plug) is a high-quality, robust AC connector designed to securely connect APsystems micro-inverters to the three-phase 5-core AC bus cable. It ensures a reliable, durable and standards-compliant electrical connection – ideal for professional use in commercial and domestic installations.More informationFunction & ApplicationThis 40A plug is used to connect APsystems micro-inverters directly to the 5-core AC bus cable. The connector is manufactured to European standards, offers high current-carrying capacity and maximum operational reliability. It is fully compatible with the APsystems QT series and other three-phase installations.Key benefits40A rated current – ideal for high-power micro-inverter systemsIP67 protection rating – watertight when fully connectedHigh electrical safety:Rated voltage: 600 V ACContact resistance ≤ 50 mΩInsulation resistance ≥ 500 MΩTest voltage: 3000 VRobust mechanics – ≥ 500 mating cyclesCompatible with cable cross-sections 2.5–10 mm²Quick, tool-free installationTechnical dataTypeAC connector (5C, 40A, male)Item number2301511002Rated voltage600 VRated current40 ACable cross-section2.5 – 10 mm²Protection classIP67 (when fully connected)Operating temperature−40 °C to +105 °CMating cycles≥ 500Dimensions105.4 mm length × Ø 47.1 mmStandard/TypeEN200-2105-101-02ApplicationsThree-phase APsystems QT-2 and QT series5-core APsystems AC bus cable installationsCommercial & industrial PV projectsPV system extensions or replacement of faulty connectorsContents1× APsystems AC connector 40A (male) – suitable for 5C bus cables.
APsystems end cap for 5-core bus cable (2.5 mm²)
The APsystems end cap for 5-core AC bus cables is an essential accessory for the safe, compliant and durable installation of APsystems micro-inverter systems. It has been specially designed for 5-core bus cables with a conductor cross-section of 2.5 mm² and reliably protects the cable end from environmental influences.More informationWhy an end cap is necessaryExposed cable ends pose a safety risk – particularly in outdoor environments. The end cap seals the bus cable watertight and prevents the ingress of moisture, dust or dirt. This enhances the operational safety of the entire PV installation and effectively prevents corrosion.Advantages of the APsystems end capPerfectly matched to the APsystems 5-core AC bus cable with 2.5 mm² (H07)Watertight seal to protect against weather and environmental influencesQuick installation without special tools – ideal for installersDurable materials for long-term outdoor useIncreased operational reliability thanks to professional cable terminationTypical applicationThe end cap is fitted at the end of a cable run of the APsystems 3-phase bus cable – for example, in systems with QT2 micro-inverters. It ensures that the final bus cable port is permanently protected and terminated in accordance with standards.CompatibilityAPsystems AC bus cable, 5-core, 2.5 mm² (H07)Suitable for APsystems 3-phase micro-inverters (e.g. QT2 series)Not suitable for 4 mm² bus cables (separate end cap required)Warranty & DurabilityThe end cap is designed for long-term outdoor use and contributes significantly to the safety and reliability of the entire PV system.
APsystems 40A AC connector (EN, 5-pin, female)
The APsystems 40A AC connector (female) serves as a reliable, weatherproof connection component for 5-core AC bus cables in APsystems PV installations. It is paired with the compatible 40A plug and ensures a secure, mechanically robust and permanently sealed connection in the AC string.More informationHighlightsFor 5-core AC bus cables (L1, L2, L3, N, PE)40A rated current – ideal for high-power micro-inverter systemsIP67 protection rating after connection – waterproof up to 1m / 30minHigh electrical safety thanks to 600V rated voltage & high insulation valuesRobust construction – at least 500 mating cyclesSuitable for conductor cross-sections of 2.5–10 mm²Technical dataRated voltage600 V ACRated current40 AContact resistance≤ 50 mΩInsulation resistance≥ 500 MΩTest voltage3000 V ACCable cross-section2.5 – 10 mm²Protection ratingIP67 (locked/plugged)Operating temperature-40°C to +105°CDimensionsLength approx. 107.8 mm · Ø 47.1 mmPart numberEN200-2205-101Item number2301512002ApplicationThe AC connector (socket) is used to connect the AC bus cable to APsystems micro-inverters, as well as extension and connection cables. It is compatible with the 40A AC plug from the same series.Safety & ReliabilityThanks to its high protection rating, robust materials and excellent electrical performance, the connector meets all the requirements for a professional PV installation. The connector is protected against moisture, dust and extreme temperature fluctuations.
APsystems Instrument Transformer (200A/66.6mA)
The APsystems current transformer (200A/66.6mA) enables precise measurement of current values in three-phase or single-phase PV systems and is ideal for feed-in control and energy management with the APsystems ECU-C.More informationProduct overviewThe APsystems current transformer (type XH-SCT-T24/200) is designed for high-precision current measurement in photovoltaic systems. It is typically used in conjunction with the APsystems ECU-C communication gateway to reliably monitor grid load, consumption and feed-in. With a rated current measurement of up to 200A and a secondary current of 66.6mA, it provides precise data for dynamic power control.Key featuresRated current: 200ASecondary current: 66.6mAType: XH-SCT-T24/200Cable length: 1 m (UL1015, 24 AWG)Two-wire signal cable: White (S1) and Black (S2)Mounting: Snap-on connector – quick installation possibleApplication: Consumption and feed-in metering for PV systemsTechnical dataDimensions: approx. 66.8 mm height, 34.2 mm width, 49.8 mm depth (see drawing)Cable routing: suitable for typical domestic connection cablesSafe and robust: designed for long-term useAreas of applicationThe measuring transformer is used for:Measuring the domestic grid load for feed-in managementMonitoring consumption values in real timeDynamic control of APsystems micro-inverters via ECU-CLoad management and prevention of grid backflowContents1× APsystems current transformer (200A/66.6mA)Fixed connection cable (1 m, 24 AWG)NoteThe current transformer is intended exclusively for use with compatible APsystems energy management systems and must only be installed by qualified electricians.
APsystems three-phase 5C bus cable (2.5 mm², H07, 2.4 m)
The APsystems 3-phase 5C bus cable (2.5 mm², H07RN-F) provides a reliable connection between APsystems micro-inverters and the mains supply. With its robust construction, integrated connectors spaced 240 cm apart and standard-compliant colour coding, it is ideal for commercial and industrial PV installations.More informationHighlightsThree-phase 5-core AC bus cable for APsystems micro-inverters2.5 mm² H07RN-F – robust, UV-resistant and suitable for outdoor use2.4 m plug spacing, ideal for uniform module rowsOne cable set contains 40 pre-assembled connectorsStandard-compliant colour coding: brown (L1), black (L2), grey (L3), blue (N), green/yellow (PE)IP67 connectors – high water resistance & safety marginsMechanically robust: ≥250 mating cyclesTechnical dataCable typeH07RN-F, 5-core, 2.5 mm²Cable length per segment2.4 m (connector spacing)Number of connectors40 per cable harnessContact resistance< 20 mΩInsulation resistance≥ 500 MΩDielectric test4000 V DC / 60 sProtection classIP67Connector service life≥ 250 mating cyclesColour codingBrown = L1Black = L2Grey = L3Blue = NeutralGreen/Yellow = EarthApplicationsCommercial & industrial photovoltaic systemsCabling of APsystems micro-inverters (QT series)Three-phase modular feed-in systemsSeries cabling of large module arraysConclusionThe APsystems 3-phase 5C bus cable is the robust, safe and efficient solution for professional PV installations with micro-inverters. Thanks to high-quality materials, IP67 connectors and optimal length, it ensures a reliable and long-lasting AC connection.
APsystems Signal Amplifier
The APsystems signal booster ensures stable and reliable communication between your ECU gateway and the micro-inverters – ideal for larger installations, complex building layouts or long distances.More informationWhy a signal booster is importantIn PV installations, signal loss can occur due to long distances, concrete walls, metal structures or sources of interference. The APsystems signal booster extends the range of wireless Zigbee communication and ensures that all micro-inverters remain reliably connected to the ECU.Key features & benefitsImproved wireless range for stable data transmissionIEEE 802.11b/g/n – compatible with proven wireless standardsOperating frequency 2400–2500 MHz (Zigbee/Wi-Fi range)Ideal for large or complex installationsPlug-and-play installation – ready for immediate useParticularly suitable for use with ECU-C and ECU-RTechnical dataModelAPsystems Signal Booster (EU)StandardIEEE 802.11b/g/nFrequency range2400–2500 MHzCompatibilityECU-C, ECU-R, ECU-BItem number2376010003InstallationIndoor useApplicationsLarge commercial installationsFacilities comprising multiple building sectionsInstallations with radio obstacles (concrete ceilings, steel halls, etc.)Optimisation of ECU-C or ECU-R communicationScope of deliveryAPsystems signal amplifierMains adapterQuick start guideConclusionThe APsystems signal booster is the perfect addition to PV systems where a stable Zigbee wireless connection is required. It increases range, reliability and communication quality – a small accessory with a big impact on the entire monitoring system.
APSystems ECU-C – Communication gateway for micro-inverters
The APSystems ECU-C is the intelligent communication gateway for APsystems micro-inverters. It collects detailed performance data at module level, enables precise real-time system monitoring and offers advanced control functions such as dynamic feed-in limitation and consumption metering.More informationHighlights of the ECU-CReal-time monitoring of every single micro-inverterZigBee communication with up to 100 invertersAdvanced energy analysis via EMA Web & AppIntegrated measurement of PV yield, consumption and grid feed-inDynamic feed-in limitation (0–100%)Control of external loads (e.g. boilers) via relaysLAN & Wi-Fi – flexible network connectivitySimple installation & intuitive initial configuration3-year manufacturer’s warrantyTechnical dataCommunication (WR → ECU)ZigBee 2.4 GHzMax. number of WRup to 100Communication (ECU → EMA)Ethernet / Wi-FiUSB outputs2× 5V DC, 0.5ARS232 / RS485StandardPower consumption3 WPower supply110–277 VAC or 12–16 V DCDimensions (L×W×H)210 × 120 × 41 mmWeight0.5 kgOperating temperature–40 °C to +65 °CProtection ratingIP20 (indoor use)Warranty3 yearsApplicationsResidential and commercial installations with APsystems micro-invertersModule-level monitoringLoad management & self-consumption optimisationDynamic feed-in limitation (e.g. 70% rule)Your benefits with the ECU-CThe ECU-C offers full transparency and control over your photovoltaic system – from the output of individual modules to grid parameters. Ideal for installers, operators and sophisticated system designs.The APSystems ECU-C communication gateway is the indispensable link between your micro-inverters and the EMA monitoring platform. It ensures precise real-time monitoring, secure data transmission and intelligently controlled energy flows – perfect for modern solar projects.
APsystems QT2 – 3-phase micro-inverter for 4 modules
The APsystems QT2 is a high-performance three-phase quad micro-inverter, designed for modern PV systems with high module power ratings. With up to 2,000 VA of continuous AC output power, two MPPT trackers and four independent input channels, the QT2 offers maximum flexibility combined with the highest level of safety – ideal for commercial applications, solar carports and demanding residential installations.More informationMaximum safety & efficiencyThe APsystems QT2 is fully encapsulated and operates at low DC voltage, which significantly increases safety compared to traditional string systems. An integrated protection relay and IP67/NEMA 6 protection rating ensure maximum robustness and durability, even under demanding weather conditions.4 inputs for modules up to 500–600 W2 MPPTs for optimal yield maximisationSymmetrical 3-phase AC outputEncrypted ZigBee communicationUp to 20-year warranty (manufacturer’s specification)Low DC input voltage for maximum personal safetyQuick and easy to installThanks to its plug-and-play design, standardised accessories and identical cabling systems, the QT2 can be installed particularly quickly – without the need for a DC string design. The solution significantly reduces installation errors, stockholding costs and installation times (according to product documentation, pages 2–3) [oai_citation:0‡APsystems Commercial Flyer - DE.pdf](sediment://file_0000000031ac71f49734d9fc4a702804).Intelligent real-time monitoringVia the APsystems ECU-R / ECU-C (Energy Communication Units), the QT2 provides comprehensive panel monitoring. The EMA Monitoring Platform and app offer:Real-time monitoring at module levelRemote maintenance, fault alerts & diagnosticsOnline layout & configuration functionsOptional: consumption & grid data (with ECU-C)Ideal for commercial applications, carports & challenging rooftopsThe APsystems QT2 has been specifically designed to meet the requirements of high-performance PV modules. According to the datasheet, it is particularly suitable for solar carports, multi-family homes, complex roof orientations and commercial installations (page 2) [oai_citation:1‡APsystems Commercial Flyer - DE.pdf](sediment://file_0000000031ac71f49734d9fc4a702804).Technical highlights (excerpt)Max. continuous AC output power2000 VAMPPT tracker2Inputs4 Module connectionsCommunicationZigBee (encrypted)Protection classIP67 / NEMA 6InstallationOutdoor, optimised heat dissipationWarrantyUp to 20 years (manufacturer)Further technical details available on request or in the official data sheet.
REFUlink RL-10 – Communication module for REFUsol inverters
REFUlink RL-10The REFUlink RL-10 is the central communication and monitoring unit for photovoltaic systems with REFUsol inverters. It connects different generations of inverters, collects operational data and enables comprehensive system monitoring via REFUview or REFUlog.More informationWhat is the REFUlink?The REFUlink acts as an intelligent interface between inverters and monitoring portals. It ensures reliable data collection, system monitoring and stable communication in PV systems – particularly in systems with a mix of REFUsol inverter generations.HighlightsCentral communication platform for REFUsol invertersData collection and forwarding to REFUview / REFUlog4 digital inputs for power and grid controlSupports USS, MODBUS and RTPIdeal for systems with grid requirements (e.g. active/reactive power control)Compatible with various REFUsol generationsRobust design with metal housingTechnical dataModelREFUlink RL-10Item number924030Power supplyUNO-PS / 1 AC / 24 DC / 30 WAC voltage100–240 VFrequency45–65 HzMax. power consumption>10 WCommunicationRS485, Ethernet, digital inputsProtocolsUSS, MODBUS, RTPMemory16 GBOperating temperature–25 °C to +55 °CProtection classIIIDimensions (W × H × D)115 × 33 × 125 mmWeight< 0.5 kgInstallationIndoor use / wall mountingWarranty2 yearsApplicationsCommercial PV systemsSolar parks with different generations of REFUsol invertersSystems with extended grid requirements (active/reactive power control)Monitoring and remote monitoring solutionsYour benefitsThe REFUlink optimises the monitoring and communication of your photovoltaic system. It ensures reliable data transmission, increases system transparency and enables compliant system control – ideal for professional PV projects.
REFUsol 20K-2T - String inverter
The REFUsol 20K-2T is a powerful, compact inverter with two MPP trackers and an efficiency of up to 98.6% – ideal for commercial and industrial photovoltaic systems.More informationREFUsol 20K-2T – New flexibility meets compatibilityThe REFUsol 20K-2T inverter offers a forward-looking solution for small to medium-sized PV projects. With its two independent MPP trackers, it allows flexible adaptation to different roof pitches and system designs. Thanks to its compact design and high power density, the unit is suitable for both rooftop and ground-mounted systems.Integration into existing systems is straightforward via Ethernet or a WiFi logger (optional). The inverter can be conveniently monitored remotely via the REFUview online platform – including a modern user interface, performance analysis and system overview throughout the entire warranty period.Key features2 independent MPP trackers for flexible string configurationMax. efficiency: 98.6% / European efficiency: 98.2%Long-term overload capacity up to 110%Compatible with older REFUsol inverters – ideal for repoweringIntegrated DC switch and comprehensive protection functionsIP65 protection rating for indoor and outdoor useIntegration via RS485, USB, Ethernet or WiFi (optional)Warranty: 10 yearsTechnical data – REFUsol 20K-2TItem no.853P020Recommended PV output (kWp)30Max. input voltage (V)1100Nominal input voltage (V)650Number of MPP trackers2Max. current per MPPT (A)26DC connectionMC4Rated power (kW)20Max. AC power (kVA)22Max. output current (A)31.9Rated output voltage (V)3P/N/PE: 230/400TopologyTransformerlessProtection classIP65Dimensions (H × W × D)430 × 520 × 189 mmWeight22 kgCoolingFanNoise level< 40 dBAMax. operating temperature+60 °C (derating > 45 °C)Protection functionsAnti-islanding, DC reverse polarity, overvoltage, overcurrent, earth fault, overtemperatureCertificatesVDE-AR-N 4105, EN 50549, CEI 0-21, G98/G99, etc.Interfaces & communicationRS485 / USB: integratedEthernet / WiFi: optional (item no. 924024 / 924025)Compatible with REFUview online monitoringThe REFUsol 20K-2T combines efficiency, compatibility and future-oriented technology in a compact unit – the perfect choice for commercial PV systems and repowering projects.
APsystems ELT-12-EU – 12 kW 3-phase hybrid inverter
The APsystems ELT-12-EU is a high-performance, three-phase AC-coupled energy storage system for residential photovoltaic installations. It enables efficient charging and discharging of low-voltage batteries, increases the self-consumption rate and provides a reliable emergency power supply – making it ideal for retrofitting or expanding existing PV systems.More informationModern energy management for maximum independenceThe ELT series has been specially developed for residential solar installations and combines intelligent energy control, high safety standards and flexible application options. The system delivers up to 12,000 VA of power in normal operation and provides up to 18,000 VA in the event of an emergency power cut. This ensures that essential loads remain reliably supplied even during a power cut.3-phase AC-coupled battery inverterFor 48 V low-voltage batteries – particularly safe & easy to installOptimisation of self-consumption rate through intelligent PV managementEmergency power & off-grid function for maximum supply reliabilityReal-time monitoring via the APsystems platform (EMA)Compact design – ideal for detached housesWhy choose the ELT series?With intelligent energy management software, the system automatically adapts to your consumption profiles, solar output and – where available – dynamic electricity tariffs. This ensures you always use your solar power at the best time – for maximum savings and efficiency.Peak shaving: reducing peak loads to lower electricity costsSmart time control: charging when tariffs are low, discharging when prices are highUse more solar power: store during the day, use in the eveningEasy retrofitting: Compatible with almost all existing PV systemsSafe 48 V technology: protection class optimised for residential useEmergency power & off-grid functionIn the event of a power cut, the ELT-12 automatically takes over the supply to critical loads. This makes it ideal for households requiring a high level of supply reliability.Immediate switchover to off-grid modeUp to 18 kVA emergency power outputStable supply across all three phasesRemote configuration & supportThe entire system can be conveniently configured remotely via the APsystems cloud platform (EMA). Firmware updates, diagnostics and settings can be carried out without a technician’s visit – ideal for installers and operators.Remote firmware updatesOnline monitoring of PV yield, consumption & grid powerCloud-based system management for installersTechnical highlightsRated power: 12,000 VAEmergency power output: up to 18,000 VABattery voltage: 48 V (low voltage)System type: 3-phase, AC-coupledCommunication: WiFi / LAN / Cloud monitoringYour benefits with APsystems ELT-12-EUWith the ELT-12-EU, you get a reliable, safe and future-proof energy storage system that is optimally designed for homes. It increases your self-consumption, protects against power cuts and can be easily integrated into existing PV systems.
REFUsol 20K-3T - String inverter
The REFUsol 20K-3T is a compact 20 kW string inverter with three MPP trackers and 98.6% efficiency – ideal for commercial and industrial PV systems.More informationREFUsol 20K-3T – Efficiency and flexibility for commercial PV projectsThe REFUsol 20K-3T combines advanced technology with high reliability and easy installation. With three independent MPP trackers, an efficiency of up to 98.6% and a long-term overload capacity of 110%, it is the optimal choice for rooftop and ground-mounted systems in the power range up to 20 kW. Thanks to its compact design, flexible communication interfaces and online monitoring via REFUview, the inverter can be quickly integrated and operated efficiently.Highlights3 independent MPP trackers for flexible system designsEfficiency up to 98.6% / EU efficiency 98.2%110% overload capacity for maximum energy yieldCompatible with older REFUsol models – ideal for repowering projectsCommunication via RS485, USB, Ethernet or optional WiFi loggerIntegrated DC switch and comprehensive protection functionsOnline monitoring via the REFUview platformIP65 protection rating – dust and splash-proof10-year manufacturer’s warrantyTechnical data – REFUsol 20K-3TRated power (AC)20 kWMax. AC power22 kVARecommended PV capacityup to 30 kWpMax. input voltage (DC)1100 VOperating voltage range (DC)180 – 1000 VNumber of MPP trackers3 (2 inputs per MPPT)Max. output current (AC)33.3 AGrid connection3P/N/PE – 230/400 V, 50/60 HzTopologyTransformerlessProtection ratingIP65CoolingActive (fan-assisted)Dimensions (H × W × D)480 × 585 × 220 mmWeight36 kgEfficiency (max. / EU)98.6% / 98.2%CertificatesEN 61000-6-1/3, VDE-AR-N 4105/4110, EN 50549-1Item number853P020.010Warranty10 yearsSafety & CommunicationThe REFUsol 20K-3T is equipped with an integrated DC switch, anti-islanding protection, earth fault and overtemperature monitoring, as well as overvoltage and overcurrent protection. Communication is via RS485, USB, Ethernet or optional WiFi. All operating data can be read directly on the device via the integrated LCD display, whilst the REFUview platform enables convenient remote monitoring and analysis in real time.ApplicationsCommercial rooftop installationsAgricultural businessesSmall to medium-sized industrial installationsRepowering of existing REFUsol systemsHybrid and grid-connected PV conceptsConclusionThe REFUsol 20K-3T offers an optimal balance of performance, reliability and cost-effectiveness. It is the ideal solution for specialist firms and installers who value modern communication, simple installation and long-term efficiency.
REFUsol 25K-3T - String inverter
The REFUsol 25K-3T is a compact 25 kW string inverter with three MPP trackers and an efficiency of up to 98.6% – ideal for commercial PV systems.More informationREFUsol 25K-3T – Flexible, efficient, robustWith three independent MPP trackers, the 25K-3T offers maximum freedom in string configuration for different roof orientations and complex system designs. Its high long-term overload capacity of 110%, simple installation and integrated communication interfaces make it a reliable choice for rooftops and ground-mounted installations.Highlights3 MPP trackers for flexible string configurationsEfficiency up to 98.6% (EU efficiency 98.2%)110% overload capacity for higher energy yieldCompatible with older REFUsol devices – ideal for repoweringCommunication via Ethernet, RS485, USB or optional WiFiIntegrated DC disconnect switch & comprehensive protection functionsOnline monitoring via REFUviewIP65 enclosure for indoor and outdoor use10-year manufacturer’s warrantyTechnical data – REFUsol 25K-3TRated power (AC)25 kWMax. AC power28 kVARecommended PV outputup to 37.5 kWpMax. input voltage1100 VOperating voltage range180 – 1000 VNumber of MPP trackers3Max. current per MPPT40 AMax. output current42.4 AMains connection3P/N/PE – 230/400 V, 50/60 HzEfficiency (max. / EU)98.6% / 98.2%Protection ratingIP65CoolingActive (fan-assisted)Dimensions (H × W × D)480 × 585 × 220 mmWeight36 kgCertificatesVDE-AR-N 4105, VDE-AR-N 4110, EN 50549-1, etc.Item number853P025Safety & CommunicationComprehensive protection functions: DC reverse polarity protection, anti-islanding, overcurrent/overvoltage and overtemperature protection, as well as earth fault monitoring. Communication via RS485, USB, Ethernet or optional WiFi logger. An integrated LCD display enables easy on-site operation; remote monitoring via the REFUview platform.ConclusionHigh efficiency, substantial reserves and versatile connectivity – the REFUsol 25K-3T is the robust solution for small to medium-sized commercial and industrial installations, as well as repowering projects.
REFUsol 33K-3T - String inverter
The REFUsol 33K-3T is a high-performance 33 kW string inverter with three MPP trackers and an efficiency of up to 98.6% – ideal for large commercial and industrial PV systems.More informationREFUsol 33K-3T – Maximum performance for professional applicationsAs the most powerful model in the REFUsol 3T series, the 33K-3T was developed specifically for large commercial and industrial installations. With its three independent MPP trackers and a long-term overload capacity of 110%, it delivers consistently high energy yields, even with complex roof orientations or mixed module arrays. The compact design and robust IP65 housing ensure easy integration and reliable operation under all conditions.Highlights33 kW nominal power at 37 kVA AC power3 independent MPP trackers for flexible string layoutsEfficiency up to 98.6% / EU efficiency 98.2%110% overload capacity for maximum energy yieldCompatible with older REFUsol inverters – ideal for repoweringCommunication via RS485, USB, Ethernet or optional WiFi loggerRemote monitoring via the REFUview platform with performance analysisIP65 housing with active cooling system10-year manufacturer’s warrantyTechnical data – REFUsol 33K-3TRated power (AC)33 kWMax. AC power37 kVARecommended PV outputup to 49.5 kWpMax. input voltage1100 VOperating voltage range180 – 1000 VNumber of MPP trackers3Max. current per MPPT40 AMax. output current56 AMains connection3P/N/PE – 230/400 V, 50/60 HzEfficiency (max. / EU)98.6% / 98.2%Protection classIP65CoolingActive (fan-assisted)Dimensions (H × W × D)480 × 585 × 220 mmWeight36 kgCertificatesVDE-AR-N 4105, VDE-AR-N 4110, EN 50549-1, etc.Item number853P033Safety & CommunicationThe REFUsol 33K-3T features an integrated DC load break switch as well as comprehensive protection mechanisms against DC reverse polarity, earth fault, overtemperature, overcurrent and overvoltage. Communication takes place via RS485, USB or Ethernet; a WiFi logger is available as an option. The integrated LCD display enables simple operation and displays all operating data in real time. Alternatively, monitoring can be carried out conveniently via the REFUview online platform.ConclusionWith high efficiency, robust construction and versatile communication options, the REFUsol 33K-3T is the perfect solution for medium to large-scale PV systems in the commercial and industrial sectors – a future-proof investment for sustainable energy generation.
APsystems APbattery 10.24 kWh – 51.2 V storage system
The APsystems APbattery 51.2 V / 10.24 kWh is a modular LiFePO4 energy storage system for single-phase and three-phase PV systems. When used in conjunction with APsystems ELT storage inverters, it enables a high self-consumption rate, peak load shaving and reliable energy management for both residential and commercial applications.More informationHighlights10.24 kWh usable capacity at 51.2 V nominal voltage (low-voltage system)LiFePO4 technology – high cycle stability, high safety, no cobaltModularly expandable by connecting multiple battery modules in parallelOptimal compatibility with APsystems ELT-12-EU and other APstorage componentsIntegrated BMS (Battery Management System) for cell balancing, overcurrent, short-circuit and temperature protectionCompact, stackable design for space-saving wall or floor mountingSuitable for optimising self-consumption, emergency power and backup solutionsLow-maintenance operation and long service life with several thousand charge cyclesTechnical data (excerpt)Nominal voltage51.2 V (low-voltage LiFePO4)Rated capacity10.24 kWhNominal charge/discharge currente.g. 100 A (depending on system configuration)TechnologyLithium iron phosphate (LiFePO4)Recommended operating temperature rangetypically 0 … +50 °C (charging) / −10 … +50 °C (discharging)Enclosure protection classIP protection rating suitable for indoor use (e.g. IP20/IP21, depending on the model)CommunicationCAN / RS485 for connection to APsystems inverters and energy managementInstallationFloor or wall mounting, stackable systemWarranty (manufacturer)Long-term product and performance warranty in accordance with APsystems terms and conditionsSafety & System IntegrationThe integrated Battery Management System (BMS) monitors the voltage, current, temperature and SoC of each cell and reliably protects the APbattery against overcharging, deep discharge, short circuits and overheating. In conjunction with APsystems storage inverters, communication takes place digitally via CAN / RS485, ensuring that charging and discharging power are optimally regulated.Thanks to its low-voltage design (51.2 V), the system meets high safety requirements and is ideal for residential buildings, smaller commercial premises and technical rooms with limited space.ApplicationsOptimisation of self-consumption in single-family and multi-family homesPV storage systems in small commercial premises, e.g. offices, medical practices, small businessesBackup and emergency power solutions in conjunction with suitable APsystems invertersLoad management, peak shaving and time-variable tariffsExpansion of existing APsystems storage solutionsBenefits for specialist companies & operatorsAll-in-one system: APbattery + APstorage ELT series + APsystems micro-invertersStraightforward commissioning via manufacturer-specific tools and appsModular scalability for future power requirementsHigh operational reliability and transparent monitoringWe would be happy to assist you in determining the appropriate storage capacity, combining it with APsystems inverters, and planning complete PV storage systems.
REFUsol 50K-4T - String inverter
The REFUsol 50K-4T is a highly efficient 50 kW string inverter with four MPP trackers and an efficiency of up to 98.8% – ideal for large commercial and industrial PV systems.More informationREFUsol 50K-4T – High performance for demanding PV projectsThe REFUsol 50K-4T impresses with state-of-the-art inverter technology and maximum flexibility. Thanks to its four independent MPP trackers (two DC inputs each), even complex roof or ground-mounted layouts can be optimally implemented. With an efficiency of up to 98.8% and a long-term overload capacity of 110%, it ensures maximum energy yield and reliable continuous operation under the most demanding conditions.Highlights4 independent MPP trackers (2 DC inputs each) for flexible string configurationsMax. efficiency: 98.8% / EU efficiency: 98.2%110% overload capacity for greater energy yieldCompact, robust IP65 housing with active coolingCommunication via RS485, USB, Ethernet or optional WiFi loggerIntuitive operation via LCD display; online monitoring via REFUviewIntegrated DC load disconnect switch and comprehensive protection functions10-year manufacturer’s warrantyTechnical data – REFUsol 50K-4TRated power (AC)50 kWMax. AC power55 kVARecommended PV outputup to 75 kWpMax. input voltage (DC)1100 VOperating voltage range (DC)180 – 1000 VMPP operating range540 – 850 VNumber of MPP trackers4 (2 inputs each)Max. current per MPPT40 AMax. short-circuit current50 AMax. output current (AC)83.3 AMains connection3P/N/PE – 230/400 V, 50/60 Hz (310–480 V range)THDi< 3 %Power factor1 (0.8 inductive ... 0.8 capacitive)TopologyTransformerlessProtection classIP65CoolingActive (fan-assisted)Dimensions (H × W × D)480 × 585 × 220 mmWeight37 kgDisplayLCDItem number853P050Warranty10 yearsSafety & CommunicationThe REFUsol 50K-4T features an integrated DC load break switch and comprehensive protection mechanisms against anti-islanding, DC reverse polarity, reverse current, earth fault, overtemperature, overvoltage and overcurrent. Communication is via RS485, USB, Ethernet or an optional WiFi logger. Remote monitoring and data analysis are possible via the REFUview platform. An integrated LCD display also enables convenient local operation.ApplicationsCommercial rooftop installations and carport systemsIndustrial and agricultural installations in the medium-power segmentGround-mounted systems with varying orientationsRepowering and expansion of existing PV systemsConclusionThe REFUsol 50K-4T combines maximum efficiency with high system flexibility and robust construction. The ideal choice for professional photovoltaic projects that prioritise reliability, future-proofing and maximum performance.
REFUsol 110K-10T – String inverter
The REFUsol 110K-10T is an efficient 100 kW string inverter featuring ten MPP trackers, 150% DC derating and IP66 protection – ideal for large commercial and industrial installations.More informationREFUsol 110K-10T – Maximum efficiency and flexibilityWith its ten independent MPP trackers, the REFUsol 110K-10T offers maximum freedom in system planning – perfect for complex rooftop and ground-mounted configurations. Thanks to 150% DC derating and an efficiency of up to 98.6%, the inverter achieves optimal energy yields even in demanding projects. The robust IP66 housing, active cooling and comprehensive communication options ensure a durable and networked solution.Highlights10 independent MPP trackers for flexible system design150% DC overload capacity for maximum energy yieldEfficiency up to 98.6% / EU efficiency 98.3%Integrated PID recovery and AFCI protectionCommunication via RS485, USB, Ethernet or optional WiFiOnline monitoring via the REFUview platformIP66 protection rating, active cooling and low-noise operation (< 60 dBA)10-year manufacturer’s warrantyTechnical data – REFUsol 110K-10TRated power (AC)100 kWMax. AC power110 kVA (@ 45 °C) / 100 kVA (@ 50 °C)Recommended PV powerup to 150 kWpMax. input voltage (DC)1100 VOperating voltage range (DC)180 – 1000 VMPPT operating range500 – 890 VNumber of MPP trackers10Max. current per MPPT40 AMax. short-circuit current50 AMax. output current167.2 A @ 380 V / 159.5 A @ 400 VMains connection3P/N/PE – 380/400/415 V, 50/60 HzPower factor1 (0.8 inductive … 0.8 capacitive)TopologyTransformerlessProtection classIP66CoolingActiveDimensions (H × W × D)695 × 970 × 325 mmWeight75 kgItem number854P110Warranty10 yearsSafety & CommunicationThe REFUsol 110K-10T is equipped with an integrated DC switch, Type II surge protection (DC & AC), anti-islanding, DC reverse polarity protection, overcurrent and earth fault protection, as well as temperature monitoring. Communication is via RS485, USB, Ethernet or optional WiFi. All operating data can be conveniently monitored and analysed via the REFUview platform.ApplicationsCommercial rooftop systemsMedium-sized industrial installationsGround-mounted projects and carport solutionsRepowering and modernisation of existing systemsConclusionThe REFUsol 110K-10T combines maximum efficiency, flexible planning and modern communication technology. It is the ideal solution for specialist companies that value robust technology and easy integration into large photovoltaic systems.
REFUsol 125K-10T – High-performance inverter
The REFUsol 125K-10T is a highly efficient 110 kW string inverter featuring ten MPP trackers, 150% DC derating and IP66 protection – ideal for large commercial and industrial PV systems.More informationREFUsol 125K-10T – Maximum performance for large PV systemsThe REFUsol 125K-10T has been specially developed for large-scale commercial and industrial installations. With ten independent MPP trackers, up to 150% DC overload capacity and an efficiency of up to 98.6%, the inverter achieves excellent yields even under demanding conditions. The IP66 aluminium housing with active cooling ensures durability, safety and reliable operation in all weather conditions.Highlights10 MPP trackers for maximum flexibility in large installations150% DC oversizing for higher energy yieldsEfficiency 98.6% / EU efficiency 98.3%Integrated PID recovery & AFCI protectionCommunication via RS485, USB, Ethernet or optional WiFiOnline monitoring via the REFUview platformIP66 protection rating and active cooling for maximum reliability10-year manufacturer’s warrantyTechnical data – REFUsol 125K-10TRated power (AC)110 kWMax. AC power125 kVA (@ 45 °C) / 110 kVA (@ 50 °C)Recommended PV powerup to 165 kWpMax. input voltage (DC)1100 VOperating voltage range (DC)180 – 1000 VMPPT operating range500 – 890 VNumber of MPP trackers10Max. current per MPPT40 AMax. short-circuit current50 AMax. output current190 A @ 380 V / 181.2 A @ 400 VMains connection3P/N/PE – 380/400/415 V, 50/60 HzPower factor1 (0.8 inductive … 0.8 capacitive)TopologyTransformerlessProtection classIP66CoolingActive (fan-assisted)Dimensions (H × W × D)695 × 970 × 325 mmWeight75 kgItem number854P125Warranty10 yearsSafety & CommunicationThe REFUsol 125K-10T features comprehensive safety functions: integrated DC switch, Type II surge protection (DC & AC), anti-islanding, reverse polarity and earth fault protection, as well as overcurrent and temperature monitoring. Communication is via RS485, USB, Ethernet or optional WiFi. All performance and operating data can be monitored and analysed in real time via the REFUview platform.ApplicationsLarge commercial and industrial facilitiesOpen spaces with varying orientationsCarports, hall roofs and solar parksRepowering and modernisation of existing systemsConclusionThe REFUsol 125K-10T combines maximum efficiency, flexible configuration and future-proof communication. A reliable, high-performance solution for modern large-scale PV systems that require maximum energy yield and safety.
REFUsol 350K-8T - String inverter
The REFUsol 350K-8T is a high-performance central inverter with eight MPP trackers, up to 99.05% efficiency and 1,500 V DC – ideal for large commercial and industrial installations.More informationREFUsol 350K-8T – Maximum performance for large-scale projectsThe REFUsol 350K-8T has been specially developed for use in large commercial and industrial PV systems. Eight independent MPP trackers with a total of 32 DC inputs (4 per MPPT) offer maximum flexibility for complex system designs. With an efficiency of up to 99.05% and a wide DC voltage range of 500–1,500 V, the inverter enables efficient system design and maximum energy yields.The robust IP66 enclosure, intelligent air cooling and comprehensive communication options make the 350K-8T the ideal solution for large PV parks, roof clusters and carport installations. Features such as AFCI, PID recovery and integrated surge protection modules (SPD Type II) enhance operational safety and system availability.Highlights8 MPP trackers with a total of 32 DC inputs (4 per MPPT)Max. efficiency 99.05% / EU efficiency 98.8%Integrated I-V curve scan & intelligent string protectionIntegrated AFCI (arc fault detection) & PID recoveryWide DC input range: 500–1,500 V / MPPT range 860–1,300 VIP66 protection rating with intelligent air cooling (< 60 dBA)Communication via RS485, USB, Ethernet/WiFi (optional) or integrated PLCLocal operation via LED & Bluetooth app, remote monitoring via REFUview10-year manufacturer’s warrantyTechnical data – REFUsol 350K-8TMax. AC power352 kVA @ 35 °C / 320 kVA @ 45 °C / 295 kVA @ 50 °CMax. output current (AC)254.1 ARated output voltage3P/PE – 800 V (range 640–920 V)Rated output frequency50/60 Hz (range 45–55 / 55–65 Hz)Power factor1 (0.8 inductive … 0.8 capacitive)Recommended PV powerup to 525 kWpMax. input voltage (DC)1,500 VDC operating range500–1,500 VMPPT operating range860–1,300 VNumber of MPP trackers / DC inputs8 MPPT / 32 inputs (MC4)Max. current per MPPT60 AMax. short-circuit current100 ATHDi< 3 %TopologyTransformerlessProtection ratingIP66Operating temperature−30 … +60 °CMax. operating altitude4,000 mDimensions (H × W × D)828 × 1,159 × 366 mmWeight113 kgDisplay / ControlsLED & Bluetooth appCommunicationRS485 / USB / Ethernet / WiFi (optional) / Integrated PLCItem number850P350Warranty10 yearsSafety & ConnectivityThe REFUsol 350K-8T offers comprehensive safety through integrated protection mechanisms against anti-islanding, DC reverse polarity, reverse current, earth fault, overtemperature, overvoltage and overcurrent. In addition, SPD Type II (DC & AC), AFCI and PID recovery are integrated as standard. Local operation is via LEDs and a Bluetooth app, whilst remote monitoring is conveniently possible via the REFUview platform.ApplicationsLarge commercial and industrial facilitiesOpen-space parks with multiple orientationsCarport and industrial roof clustersRepowering and expansion of existing PV systemsConclusionThe REFUsol 350K-8T combines maximum efficiency, advanced safety features and intelligent diagnostic options. A future-proof choice for large-scale professional PV projects that prioritise maximum performance, durability and connectivity.
The central role of the inverter
An inverter is far more than just a power converter. It acts as the intelligent control unit of your photovoltaic system and performs a wide range of essential functions:
- Conversion of direct current (DC) into alternating current (AC)
- Monitoring of voltage, temperature and grid quality
- Control of energy flows within the building
- Integration of battery storage systems and smart home solutions
- Safe feed-in to the public grid
- System monitoring and remote access
Types of inverters
Depending on the system design and requirements, different types of inverters are used:
PV inverters (string inverters)
The standard solution for grid-connected systems without storage. High efficiency and reliable grid synchronization make them widely used in residential and commercial applications.
Hybrid inverters
Combine PV systems and battery storage in one device. Ideal for self-consumption optimization, load management and increased energy independence.
Battery inverters
AC-coupled systems for retrofitting battery storage. Ideal for upgrading existing PV systems.
Microinverters
Installed directly at the module level – ideal for shaded conditions, complex roof layouts or east-west orientations. Increase system reliability and enable module-level monitoring.
Key selection criteria
- System size & string design
- Compatibility with battery storage
- Communication & monitoring (app, web, Modbus, LAN/WiFi)
- Grid standards & compliance (e.g. VDE / grid codes)
- Efficiency & performance
- Future readiness (smart meters, dynamic tariffs)
Inverters in in-roof systems (BIPV)
Especially in in-roof photovoltaic systems such as Solrif®, the precise coordination between modules, mounting system and inverter is essential.
deSonna offers carefully selected solutions that:
- are optimized for in-roof systems
- enable high efficiency even on complex roof structures
- are designed for durable and low-maintenance operation
Future-ready technologies
Modern inverters are already prepared for future energy requirements:
- Battery storage integration
- Smart grid compatibility
- Dynamic electricity tariffs
- Load management & self-consumption optimization
- E-mobility integration (EV charging)
Your partner for professional photovoltaic solutions
With deSonna, you benefit from over 20 years of experience in in-roof photovoltaics and BIPV. We support you in selecting the right inverter solution – tailored to your project, your requirements and your system.
Frequently asked questions about inverters
What is the function of an inverter in a photovoltaic system?
The inverter converts the direct current generated by the PV modules into usable alternating current and also performs key control, monitoring and protection functions within the system.
When is a hybrid inverter useful?
A hybrid inverter is particularly useful when combining a photovoltaic system with battery storage or when planning a future storage upgrade.
What should be considered when choosing an inverter?
Key factors include system size, string design, storage compatibility, efficiency, communication interfaces and compliance with relevant grid and safety standards.