APsystems QT22000VA three-phase microinverter for four PV modules

Overview

QT2 is APsystems' native three-phase quad microinverter, listed as QT2 and QT2-EU in its European certificates. One unit takes four PV modules of 315–670Wp on four inputs grouped in two MPP trackers, and delivers a balanced 2000VA into a 400V three-phase grid at 2.9A per phase. Each input accepts 20A, peak efficiency is 97%, and the 6.1kg housing is IP67. With CEI 0-21 and VDE-AR-N 4105 in its compliance list, it suits homes and commercial roofs with three-phase supply.

• 2000VA balanced output on 400V three-phase
• Four module inputs on two MPPT
• 20A input current, 25A Isc per input
• 97% peak efficiency, 99.5% MPPT efficiency
• CEI 0-21 and VDE-AR-N 4105 listed
• 12-year standard warranty, extendable to 25 years

How it works

The QT2 connects four PV modules and feeds a balanced 2000VA into a 3/N/PE 400V grid, about 2.9A per phase, so no phase-balancing across separate single-phase units is needed. The four DC inputs are grouped in two MPP trackers, each pair tracking between 28 and 45V, with 26–60V operating range, 22V start-up and 60V maximum input. Reactive Power Control and a power factor adjustable from 0.8 leading to 0.8 lagging support grid operators' requirements.

Key features

Each input accepts 20A operating and 25A short-circuit current, and APsystems recommends modules of 315–670Wp. Peak efficiency is 97%, MPPT efficiency 99.5% and night consumption 40mW. The silicone-encapsulated electronics sit in an IP67 housing without fans, rated for -40 to +65°C ambient, with derating possible where heat dissipation is poor. Galvanically isolated high-frequency transformers and an integrated safety protection relay are part of the design, and module voltage on the roof stays at low DC values.

Installation and compatibility

Units plug into the APsystems five-wire AC bus cable (L1, L2, L3, N, PE), closed with an end cap tightened to 2.5Nm and T-CONN caps on unused ports. The English datasheet allows 6 units per 2.5mm² branch and 8 per 4mm², while the manual and the German and Italian datasheets give 7 and 10; follow local rules. Leave 1.5cm free above and below, keep DC leads within 3m and mount with M8 hardware, grounding washer facing the rail.

Bipolar circuit breakers are mandatory, while leakage-current and AFCI/GFCI breakers are not recommended. The compliance list includes EN 50549-1/-10, CEI 0-21, VDE-AR-N 4105, UTE C15-712-1, UNE 217001/217002, RD 1699 and G98/G99/G100, and APsystems publishes Italian, German, French, Spanish and Polish certificates covering QT2 and QT2-EU.

Monitoring and warranty

Production data travels over encrypted ZigBee to an APsystems ECU and on to the EMA web portal and EMA Manager app, with no more than 80 inverters per ECU recommended. Start-up is confirmed by ten green LED blinks; status LEDs then show production and ECU communication. The warranty is 12 years standard, extendable to 25 years, as long as the system stays connected to EMA via the ECU; otherwise only the 2-year legal warranty applies.

Questions and answers