Deye SUN-20K-G0420kW three-phase string inverter, 2 MPPT

Overview

SUN-20K-G04 delivers 20kW (22kW maximum active power) to a three-phase 230/400V grid. Its two MPP trackers accept three strings each, up to 32A per tracker and 1000V, for up to 26kW of DC power with a 200–850V tracking range and 250V start-up. Maximum efficiency is 98.6% and European efficiency 97.8%. The 20.8kg IP65 unit needs a 40A/400V breaker and 10mm² cable, and one energy meter can manage export for up to 16 inverters.

• 18, 20 or 25kW three-phase, 230/400V
• 2 MPPT, 3 strings each, 32A per tracker
• 1000V max., 200–850V MPPT range
• 98.6% maximum, 97.8% European efficiency
• IP65, 330×508×206mm, 20.8kg
• CEI 0-21, VDE-AR-N 4105, EN 50549-1 certificates

How it works

The SUN-18K, 20K and 25K-G04 are transformerless three-phase string inverters for 220/380V or 230/400V grids. Two MPP trackers each accept three strings, with up to 32A operating and 48A short-circuit current per tracker, a 1000V maximum input, 250V start-up and a 200–850V tracking range. Maximum DC power is 23.4, 26 and 32.5kW respectively. Maximum efficiency is 98.6%, European efficiency 97.8%, and night consumption below 1W.

Key features

Export can be limited, including to zero, with an energy meter on the RS485 port and a hard or soft limit set in the menu. Up to 16 inverters can share one meter in a master-slave arrangement, so a multi-inverter plant needs only one measuring point. Residual current detection, insulation monitoring, anti-islanding and type II surge protection are integrated. Smart cooling keeps typical noise below 40dB, and Deye states a design lifetime of more than 20 years.

Installation and compatibility

Mount the 20.8kg unit vertically, or tilted by up to 15°, on a wall or structure that carries its weight, with at least 500mm to neighbouring inverters and 500mm above and below. Each inverter needs its own 40A/400V breaker and 10mm² AC cable, with up to 20m of outside cable; loads must not be connected between inverter breakers. An external leakage protection device must trip at more than 300mA.

Supported meters are the Eastron SDM630-Modbus V2 (direct up to 100A), the Eastron SDM630 MCT 40mA with external CTs from 5 to 2000A, and the CHNT DTSU666 (direct up to 80A). Deye's certificates for the SUN-(18-36)K-G04 series cover CEI 0-21, VDE-AR-N 4105, EN 50549-1 with French, Dutch and Polish versions, and the Spanish NTS, UNE 217002 and RD 647/413/1699 rules.

Monitoring and settings

A two-line LCD (1602) with keys is used to set the grid standard, power factor, export mode and protection parameters. Interfaces are RS485, RS232, Wi-Fi and LAN; remote monitoring uses a Deye Wi-Fi plug or data logger fitted in the sealed slot on the housing. Operating range is -25 to 65°C with derating above 45°C, up to 2000m. Deye no longer lists these models on its current product pages; documentation is the 2022 user manual.

Questions and answers