Fronius Symo Advanced 20.0-3-M20kW three-phase string inverter with AFCI and 2 MPPT

Overview

The Symo Advanced 20.0-3-M is the largest model of the range: a 20kW three-phase string inverter with Fronius Arc Guard arc fault detection and the Fronius Datamanager 2.0 on board (item 4,210,163). MPPT1 takes 33.0A and MPPT2 27.0A over 3+3 DC inputs, and rated power needs 420–800V MPP voltage. With the 50% oversizing Fronius permits, up to 30kWp of PV can be connected. European efficiency is 97.6%, and WLAN and Ethernet give direct access to Solar.web and Modbus TCP SunSpec.

• 10.0–20.0kW three-phase, two MPP trackers
• Integrated Fronius Arc Guard AFCI to IEC 63027
• Up to 33A on MPPT1, 200–1,000V DC input
• IP66 housing, active cooling, -25…+60°C ambient
• Lite versions without Datamanager 2.0
• CEI 0-21, CEI 0-16, VDE-AR-N 4110 and EN 50549 listed

How it works

Symo Advanced is the SnapINverter Symo platform for 10.0 to 20.0kW with an arc fault circuit interrupter added. Fronius Arc Guard watches the DC current and voltage for arc signatures and shuts the PV system down when it detects one. After a detected arc, feed-in pauses for at least 5 minutes; if several arcs occur within 24 hours, operation can stay blocked until a manual restart. Two MPP trackers handle different roof faces.

Key features

The asymmetric trackers take 27.0/16.5A on the 10.0 and 12.5kW models and 33.0/27.0A from 15.0kW, with 3+3 DC inputs over a 200–800V usable MPP range. Fronius permits 50% oversizing, which gives 15.0 to 30.0kWp of PV across the range. The 725×510×225mm IP66 housing uses active cooling and has a DIN rail for an optional type 1+2 or type 2 surge protection device.

Installation and compatibility

Where an AFCI to IEC 63027 is required, each string may carry at most 12A and the DC Con Kit 25 must not be used. Fronius warns that active module electronics such as optimisers can impair arc detection. Strings connect to screw terminals for 2.5–16mm², and the AC side uses a 5-pin terminal. The datasheet lists CEI 0-21, CEI 0-16, VDE-AR-N 4105, VDE-AR-N 4110, EN 50549-1/-2, TOR Erzeuger Typ A and IEC 63027:2023.

Monitoring and settings

Full versions include the Fronius Datamanager 2.0 with WLAN and Ethernet, Solar.web, Modbus TCP SunSpec, the Solar API, an RS485 port and six inputs plus four digital I/Os for ripple control. Lite versions have none of these on board, but keep USB, Solar Net, the floating relay and the S0 meter input, which allows feed-in limitation down to zero directly from the inverter display.

Questions and answers