Sofar Solar Mono 4 kW Grid Inverter – 4KTLM-G3

Sofar Solar 4KTLM-G3 single-phase grid-tied inverter – 4 kW, 2 MPPT, 98.2% efficiency and 4,000 m altitude

The Sofar Solar 4KTLM-G3 is a 4, 000 W single-phase grid-connected inverter (max AC power 4,400 VA) from the KTLM-G3 range. It shares the advanced architecture of the 3.6KTLM-G3 — 2 independent MPPT trackers, maximum efficiency of 98.2%, I-V curve tracking and operation up to 4,000 m altitude — whilst offering a higher rated power output suitable for homes with higher consumption or a larger PV array, up to 6,000 Wp. Supplied with a Wi-Fi dongle as standard and covered by a 10-year warranty, the 4KTLM-G3 is ideal for multi-oriented or partially shaded residential roofs, regardless of the installation site.

4,000 W nominal / 4,400 VA max: power for larger households

With a rated power of 4,000 W and a maximum AC power of 4,400 VA, the 4KTLM-G3 can supply homes with a higher daily consumption than the 3.6KTLM-G3 (3,680 W). The 10% AC power headroom (4,400 VA vs 4,000 W) provides a safety margin to absorb production peaks without clipping. The maximum output current is 20 A, compared to 16 A for the 3.6KTLM-G3.

6,000 Wp of PV power: generous sizing

The 4KTLM-G3 supports a recommended total PV power of 6,000 Wp (3,000 Wp max per MPPT). With 400 Wp panels, this corresponds to a total of 15 panels (7 or 8 per MPPT). The PV oversizing ratio of 1.5 (6,000 Wp / 4,000 W) is within the optimal range for maximising output at the start and end of the day and in winter, without the risk of excessive saturation.

2 independent MPPT trackers: the solution for complex roofs

The 4KTLM-G3 incorporates 2 independent MPPT trackers, each accepting 1 string and a maximum input current of 15A (permitted short-circuit current 22.5A per MPPT). The MPPT range extends from 80 to 550 Vdc, with a maximum input voltage of 600 Vdc and a nominal voltage of 380 Vdc. The full-power MPPT range is 200 to 500 Vdc. The start-up voltage is 90 Vdc. The two independent MPPT trackers allow two strings to be connected with different orientations, tilt angles or numbers of modules without cross-penalty — ideal for east/west-facing roofs, L-shaped roofs or partially shaded installations.

98.2% efficiency: a record for the Sofar range at Wattuneed

The 4KTLM-G3 achieves a maximum efficiency of 98.2% and a European weighted efficiency of 97.3% — the highest figures of any Sofar Solar grid-tied inverter available from Wattuneed. This superior performance compared to the TL-G3 range (97.5–97.7% max) is due to the KTLM-G3 architecture, which is optimised to minimise switching and conduction losses.

I-V curve scanning: advanced anti-shading optimisation

The 4KTLM-G3 incorporates an I-V curve scanning function — absent from the TL-G3 range. This periodic analysis of each string’s characteristic curve enables the MPPT algorithm to identify the true global maximum power point, even in the presence of partial shading that creates multiple local maxima. Combined with the two independent MPPT trackers, this I-V scanning makes the 4KTLM-G3 the most robust solution in the Sofar range for roofs with variable shading.

Maximum altitude of 4,000 m

The 4KTLM-G3 is certified for operation at altitudes of up to 4,000 m — double that of the TL-G3 models (2,000 m). This certification is particularly important for installations in mountainous areas where thin air reduces the cooling capacity of the inverters. The 4KTLM-G3 maintains its rated performance up to 4,000 m, making it suitable for any residential installation in Europe, North Africa and the Middle East.

Built-in Wi-Fi as standard: monitoring via SolarMan

The 4KTLM-G3 comes with a Wi-Fi dongle as standard, allowing immediate connection to the SolarMan monitoring portal (iOS and Android app, web interface) upon commissioning. The portal provides real-time access to instant production figures, daily graphs, monthly and annual totals, and alerts in the event of a fault.The built-inLCD screen andBluetooth app also allow for viewing and configuration directly on-site without a Wi-Fi network.

Natural convection: no fan, < 25 dB

The 4KTLM-G3 is cooled exclusively by natural convection — no fan, no mechanical parts subject to wear. The noise level is below 25 dB. Night-time power consumption is less than 1 W. The IP65 aluminium housing (349 × 344 × 164 mm) is identical to the 3.6KTLM-G3 — only the weight may vary slightly depending on the power rating.

Advanced power network management

• Zero export: optional, via external CT/meter
• Adjustable reactive power: power factor from 0.8 leading to 0.8 lagging (1 by default)
• Active power limitation: 0 to 100% of rated power, configurable
• Auto-reduction on over-frequency: in accordance with VDE-AR-N 4105 and C10/11 standards
• Islanding protection: leakage current detection and earth fault monitoring
• Type III varistor surge arrester: fitted as standard
• DC switch: optional

C10/11 certification — Compliant with Belgian standards

The Sofar Solar 4KTLM-G3 is C10/11 certified, ensuring compliance with the requirements of network operators in Belgium. With a rated power of 4,000 W, it remains below the Synergrid limit of 5,000 VA single-phase. It is also certified to VDE-AR-N 4105, G98/G99, EN 50549, IEC 0-21 and RD1699.

Key technical specifications