STP 50-41

The SMA Sunny Tripower CORE1 STP 50-41 is the 50 kW three-phase inverter that has revolutionized the world of commercial inverters: it is the world’s first free-standing string inverter, designed to stand independently without a mounting rack, drastically reducing installation time and costs for photovoltaic systems on commercial rooftops, carports, and ground-mounted installations. As the third generation of the Sunny Tripower family, it is scalable up to the megawatt range.

Free-standing design — no rack required

The CORE1 redefines the concept of commercial installation. Thanks to its self-supporting design with integrated mounting feet, no additional mounting structures are required — just a simple base. Compared to traditional wall-mounted inverters, this results in:

• Significant reduction in Balance of System (BoS) costs
• Faster installation — connection areas are fully accessible from all sides
• Lower logistics costs — the compact structure reduces transport volumes
• Flexible placement: on rooftops, on the ground, in carports, and for repowering applications

6 independent MPPTs — 12 direct string inputs

The STP 50-41 features 6 independent MPP trackers, each with 2 direct string inputs (12 total), with a maximum current of 20 A per MPPT and a maximum short-circuit current of 30 A per string input. This architecture ensures:

• Optimal management of subfields with different orientations, tilts, and string lengths
• No DC fuse required — fuseless architecture with integrated DC disconnector
• PV field oversizing up to 150% DC:AC ratio — max PV field 75,000 Wp STC
• MPP range from 500 V to 800 V (max DC voltage 1000 V)

SMA ShadeFix — integrated shading management

SMA ShadeFix is integrated as standard and automatically active. The algorithm performs an MPP scan every 6 minutes to identify the global optimal operating point even in the presence of partial shading — without additional hardware and without penalizing unshaded modules.

Integrated AFCI and I-V diagnostics — advanced safety and monitoring

The CORE1 STP 50-41 includes as standard:

• Arc-Fault Circuit Interrupter (AFCI) — detection of serial and parallel DC string arc faults, with automatic interruption and alarm. This fire safety function is mandatory in many markets and is integrated at no extra cost
• I-V curve diagnostics for the generator — measures and displays the current-voltage curve of each pair of strings, allowing remote diagnosis of degraded modules, shading, or faulty connections without physical access to the field
• Integrated Plant Control — centralized management of the entire plant’s reactive and active power
• Q on Demand 24/7 — provision of reactive power even at night, for grid support

Communication and integration

The STP 50-41 natively integrates into the SMA Commercial ecosystem:

• 2 Ethernet ports (Speedwire) for connection to SMA Data Manager and local network
• Integrated WLAN — commissioning via smartphone or tablet without additional cables
• SMA Modbus / SunSpec Modbus / Webconnect — for integration with SCADA, EMS, and third-party platforms
• Integrated multifunction relay + 2 slots for expansion modules (IO Module, RS485 Module, Sensor Module)
• Compatible with SMA ennexOS for cross-sector energy management
• Compatible with SMA Fuel Save Controller for hybrid systems with diesel generators
• Off-grid capability with the appropriate SMA solution

OptiCool cooling — maximum efficiency at high temperatures

The active OptiCool cooling system maintains optimal operating temperature even in high ambient temperatures, ensuring stable operation up to +60°C without derating. The IP65 protection rating makes it suitable for both indoor and outdoor installation.

Full technical specifications

• Model: STP 50-41
• Series: Sunny Tripower CORE1
• Manufacturer: SMA Solar Technology AG (Germany)
• AC nominal power: 50,000 W / 50,000 VA
• AC connection: three-phase 3-(N)-PE, 230/400 V, 50 Hz
• AC nominal / max current: 72.5 A / 72.5 A
• No. of MPPTs: 6 independent
• Total string inputs: 12 (2 per MPPT)
• Max DC current per MPPT: 20 A
• Max short-circuit current per MPPT / per string: 30 A / 30 A
• Max DC voltage: 1000 V
• MPP range: 500–800 V
• Max PV generator power: 75,000 Wp STC
• Max DC:AC oversizing: 150%
• Max / European efficiency: 98.1% / 97.8%
• THD: < 3%
• Topology: transformerless
• Cooling: active (OptiCool)
• Noise level: < 65 dB(A)
• Nighttime self-consumption: 4.8 W
• Protection rating: IP65
• Operating temperature: −25°C to +60°C
• DC connection: SUNCLIX
• AC connection: screw terminals
• Communication: 2× Ethernet / WLAN / RS485 (optional)
• Integrated AFCI: yes
• I-V diagnostics: yes
• SMA ShadeFix: yes (integrated)
• Standard warranty: 5 years (extendable to 10, 15, or 20 years)
• Certifications: CEI 0-16/0-21:2020, CE, VDE AR-N 4110, IEC 62109-1/2, G99 and others
• Dimensions (W×H×D): 569 × 733 × 621 mm
• Weight: 84 kg