Fronius Eco 25.0-3-S25kW three-phase project inverter with 1 MPPT

Overview

The Eco 25.0-3-S is a 25kW three-phase string inverter for commercial PV systems, item 4,210,056,040 with the Datamanager 2.0 built in. A single MPP tracker takes 44.2A over a 580–850V range, with six DC inputs and integrated string fuse holders, and up to 37.8kWp of PV can be connected. It reaches 98.2% peak and 98.0% European efficiency. Long strings are needed: Fronius recommends a minimum MPP design voltage of 600V because the Eco has no boost converter.

• 25.0 or 27.0kW three-phase, one MPP tracker
• 580–1,000V DC input, 580–850V usable MPP range
• Six DC inputs with integrated string fuse holders
• IP66 housing, 35.7kg, -25…+60°C ambient
• DIN rail for optional type 1+2 or type 2 SPD
• CEI 0-16, CEI 0-21 and VDE-AR-N 4105 listed

How it works

Eco is the commercial SnapINverter, built for long high-voltage strings on 400/230V or 380/220V three-phase grids. It has a single MPP tracker and no internal boost converter, so the minimum DC voltage depends on the actual grid voltage: the usable MPP range is 580–850V, and Fronius recommends designing for 600V minimum. Feed-in starts at 650V. In exchange, the conversion path is short, giving 98.0% European efficiency.

Key features

Both models accept up to 37.8kWp of PV and 80A array short-circuit current over six DC inputs. Integrated fuse holders protect each string, so a separate string combiner box is often unnecessary; units can be supplied with six 15A/1,000V fuses on the positive side. The maximum string fuse rating per terminal is 20A and the operating current per string 15A. A DIN rail inside takes an optional type 1+2 or type 2 surge protection device.

Installation and compatibility

The 725×510×225mm, IP66 housing hangs on the SnapINverter bracket indoors or outdoors and uses screw terminals for 2.5–16mm² conductors on the DC and the 5-pole AC side. Maximum AC overcurrent protection is 80A. When an external combiner box is used, Fronius requires its DC Connector Kit (4,251,015). The datasheet lists CEI 0-16, CEI 0-21, VDE-AR-N 4105, G98, G99 and UNE 206007-1, among others.

Monitoring and settings

Full versions carry the Fronius Datamanager 2.0 with WLAN and Ethernet, Solar.web monitoring, Modbus TCP SunSpec, the Solar API and six inputs plus four digital I/Os for ripple control receivers. Light versions have no Datamanager but keep USB logging and firmware updates, two RS422 Solar Net sockets, the floating relay output and the S0 meter input. Within one Solar Net ring, only one Datamanager is permitted, so light units are typical secondary inverters.

Questions and answers