Deye 18–21 kW Three-Phase Low-Voltage Solar Inverter

These are three-phase solar inverters for low-voltage grids, the 127/220 V and 133/230 V supplies used in parts of Latin America and on older industrial sites. All three run at 98.6% peak efficiency with two independent MPPT trackers, so a roof split across two orientations still gets tracked properly. The choice between 18, 20 and 21 kW comes down to array size and, in one case, the size of the box going on the wall.

True of every rating

• 98.6% peak efficiency and a 98.1% European weighted average at every rating.
• Two independent MPPT trackers with a 200 to 700 V window and 40 A per input.
• Wakes at 250 V and takes up to 800 V from the array.
• IP65 sealed and rated from -25 to 65 C, so an outdoor wall in real heat is fine.

Choose your rating

18 kW three-phase LV inverter with a 250 V full-load MPPT floor

Rated 18 kW with room for 27 kW of panels and 47.3 A per phase. Its useful trick is the full-load MPPT window, which starts at 250 V rather than the 300 V of the 20 and 21 kW units, so it holds full output on a shorter string or on a cold, overcast morning. Maximum output fault current is 90.4 A. The cabinet weighs 51.9 kg.

Rated AC power: 18 kW · Max PV input power: 27 kW · Max AC output current: 47.3 A · Full-load MPPT range: 250-700 V

Model code: SUN-18K-G04-LV

20 kW three-phase low-voltage inverter for a 30 kW rooftop array

Rated 20 kW and taking up to 30 kW of panels, with 52.5 A per phase. Its full-load MPPT window starts at 300 V, so it expects a longer string than the 18 kW model. Maximum output fault current is 100.4 A, which is the number your electrician needs when sizing the AC protection. It uses the same 51.9 kg cabinet as the 18 kW unit, so the mounting is identical.

Rated AC power: 20 kW · Max PV input power: 30 kW · Max AC output current: 52.5 A · Max output fault current: 100.4 A

Model code: SUN-20K-G04-LV

21 kW three-phase LV solar inverter in a lighter 23 kg cabinet

The largest of the three, rated 21 kW with 31.5 kW of panel capacity and 55.2 A per phase. It is also the odd one out physically: 23 kg in a 362 x 577 x 215 mm case, against 51.9 kg and 456 x 750 x 268.5 mm for the 18 and 20 kW units. That changes what two people can lift onto a wall unaided. Maximum output fault current is 105.4 A.

Rated AC power: 21 kW · Max PV input power: 31.5 kW · Max AC output current: 55.2 A · Weight: 23 kg

Model code: SUN-21K-G04-LV