The SI22 is Veichi's palm-size economical solar pump inverter for small installations: 0.75 to 2.2 kW, driving 110 V (D1) and 220 V (D3) three-phase pumps — and single-phase pumps with current-matched model selection. Every model accepts a wide 60–400 VDC PV input, and Veichi's simplified manual is the only document in the range that prints the recommended maximum solar array power for each model, reproduced in the table below.

Operation is one-key start/stop with automatic sunrise/sunset behaviour, and the output frequency range extends to 320 Hz. CE (EMC and LVD) certificates are published on the official product page.