Fronius Symo 4.5-3-M4.5kW three-phase string inverter with 2 MPPT

Overview

The Symo 4.5-3-M is a 4.5kW three-phase string inverter of Fronius' SnapINverter generation, item 4,210,033 with the Datamanager 2.0 built in. Two MPP trackers rated 16A each cover a 150–800V MPP range (150–800V at full power), so two roof faces can be used independently. It takes up to 9.0kWp of PV, feeds 6.5A per phase and reaches 97.2% European efficiency. WLAN and Ethernet give Solar.web monitoring, Modbus TCP and, with a meter, dynamic feed-in limitation. There is no battery input.

• 3.0–20.0kW three-phase, one or two MPP trackers
• -M versions: two MPPT at 16A, 150–1,000V input
• Datamanager 2.0 with WLAN, LAN and Modbus TCP SunSpec
• Dynamic feed-in limitation and zero feed-in with meter
• IP65 (3.0–8.2kW), -25…+60°C ambient
• Grid-tied PV only, no battery input

How it works

Symo is Fronius' transformerless three-phase string inverter for 400/230V and 380/220V grids, built on the SnapINverter platform. Power classes are 3.0, 3.7 and 4.5kW (-S and -M), 5.0, 6.0, 7.0 and 8.2kW, and 10.0 to 20.0kW (-M). It converts PV power for direct use and grid feed-in and has no battery input. The -S versions have one MPP tracker; the -M versions have two independent trackers, which Fronius' SuperFlex Design concept uses to handle irregular or multi-orientation roofs.

Key features

From 3.0 to 8.2kW the -M models accept 16A per tracker, 150–1,000V DC input and 150–800V usable MPP range, in a 645×431×204mm IP65 housing with regulated air cooling. Feed-in starts at 200V, the Dynamic Peak Manager handles MPP tracking, and night-time consumption is below 1W. Larger 10.0–20.0kW -M models use a separate IP66 housing.

Installation and compatibility

DC and AC wiring use screw terminals for 2.5–16mm² conductors. The ambient range is -25 to +60°C, and the unrestricted voltage range applies up to 2,000m altitude. With a Fronius Smart Meter at the grid connection point, the inverter can limit feed-in dynamically, down to zero export. Smart Grid Ready interfaces allow connection to ripple control receivers through six inputs and four digital inputs/outputs.

Monitoring and settings

The full version includes the Fronius Datamanager 2.0 with WLAN and Ethernet, providing Fronius Solar.web monitoring, Modbus TCP SunSpec and the Fronius Solar API (JSON). An RS485 port handles Modbus RTU SunSpec or a meter, a USB socket allows data logging and firmware updates, and two RS422 sockets link further inverters through Fronius Solar Net. A floating relay output can switch loads for energy management.

Questions and answers