Fronius Primo 3.6-13.68kW single-phase string inverter with 2 MPPT

Overview

The Primo 3.6-1 is a 3.68kW single-phase string inverter from the Fronius SnapINverter range, item 4,210,067 with the Datamanager 2.0 included. Two MPP trackers of 12A each work from 80V, with 200–800V needed for full power, and up to 5.5kWp of PV may be connected, which is the 50% oversizing Fronius allows. It feeds 16.0A at 96.8% European efficiency into a 230V supply. WLAN and Ethernet provide Solar.web monitoring and meter-based feed-in control.

• 3.0–8.2kW single-phase, two MPP trackers each
• 80–1,000V DC input, feed-in starts at 80V
• Datamanager 2.0 with WLAN and LAN in full versions
• Light versions without Datamanager, same hardware otherwise
• IP65, -40…+55°C ambient, up to 4,000m altitude
• Grid-tied PV only, no battery input

How it works

Primo is the single-phase member of Fronius' SnapINverter generation, rated 3.0, 3.6, 4.0, 4.6, 5.0, 6.0 and 8.2kW for 220/230V grids. The transformerless inverter converts PV power for self-consumption and grid feed-in; it has no battery input. Two independent MPP trackers accept strings of different length or orientation, and the Dynamic Peak Manager searches for the global power point when part of the array is shaded.

Key features

Every model accepts 80–1,000V DC with an 80–800V usable MPP range and starts feeding in at 80V. Models up to 5.0kW take 12A per tracker; 6.0 and 8.2kW take 18A. The PV array may be oversized by up to 50% above nameplate power, as Fronius confirms in its oversizing declaration. The IP65 housing (645×431×204mm, 21.5kg) uses regulated air cooling and suits indoor or outdoor mounting.

Installation and compatibility

The SnapINverter mounting bracket is fixed to the wall or a mast first, then the inverter is hung on it. DC strings use 2+2 screw terminals and the AC side a 3-pole terminal, both for 2.5–16mm² conductors. The installation instructions specify a maximum AC overcurrent protection of 1×63A. Where an RCD is required, type A is generally sufficient; Fronius recommends a type suitable for frequency converters.

The datasheet lists CEI 0-21, G98, G99, IEC 62109-1/-2, IEC 62116, IEC 61727 and VDE-AR-N 4105. Fronius notes that the 5.0, 6.0 and 8.2kW models are not fully compliant with VDE-AR-N 4105, so the certificate scope should be checked before registering one of these models with a German grid operator.

Monitoring and settings

Full versions include the Fronius Datamanager 2.0 with WLAN and Ethernet for Solar.web monitoring, Modbus TCP SunSpec, the Solar API and, with a meter, dynamic feed-in limitation. Light versions omit the Datamanager but keep USB logging and updates, Solar Net, the relay output and the S0 meter input. With a third-party S0 meter in the consumption branch, a light unit can limit feed-in between 0 and 99% by itself.

Questions and answers