Solis S6-GC3P33K03-NV-ND33kW three-phase grid-tied string inverter, 3 MPPT

Overview

The S6-GC3P33K03-NV-ND is the 33kW model of the Solis S6-GC3P(25-36)K03-NV-ND three-phase string inverter series for commercial roofs. Its three MPP trackers each accept two strings and 42A, which suits high-current modules up to 21A per string; tracking runs from 180V to 1000V. Solis recommends up to 49.5kW of PV, and output is 33kW at 50.1A/47.6A with 98.5% peak efficiency. The housing weighs 26.5kg, and the manual specifies a 63A AC protection device.

• 25, 30, 33 and 36kW, 3/N/PE 380/400V
• 3 MPPT, 42A each, two strings per tracker
• 1100V max. input, 180–1000V MPPT range
• Max. efficiency 98.5%, EU efficiency 98.0%
• String monitoring, I-V scan, optional AFCI 2.0
• Bluetooth commissioning with the SolisCloud app

How it works

The S6-GC3P(25-36)K03-NV-ND is a transformerless three-phase string inverter for grid-connected PV on commercial, agricultural and larger residential roofs. All four models have three MPP trackers with two string inputs each; every tracker accepts 42A, or 21A per string, which matches modern high-current modules. Tracking runs from 180V to 1000V with a maximum input of 1100V, and each tracker can take up to 25kW of PV.

Solis recommends a PV array of up to 1.5 times the rated power, from 37.5kW on the 25kW model to 54kW on the 36kW model. The AC output equals the rated power at 3/N/PE 220/380V or 230/400V, 50Hz or 60Hz, with a power factor adjustable between 0.8 leading and 0.8 lagging.

Key features

Every string is monitored, an I-V curve scan helps to find faulty or shaded modules, and a multi-peak scan keeps tracking stable under partial shading. Surge protection and a DC switch are built in, and AFCI 2.0 arc-fault detection is available as an option. Night-time self-consumption is below 1W.

The built-in export power management works with a Solis smart meter on the grid or load side, or with a smart CT sensor on the grid side, and can achieve zero export. The same devices provide 24-hour load monitoring in SolisCloud. For plants with several inverters, the manual refers to an external Solis EPM unit connected through the RS485 ports.

Installation and compatibility

The IP66 housing measures 355×625×250mm and weighs 25.3–26.5kg, with intelligent fan cooling. It is wall-mounted vertically or tilted back by up to 15°, with 500mm between inverters and at least 500mm above the floor. The AC side uses OT terminals on 6–25mm² copper cable; the manual lists a 63A AC protection device for the 30, 33 and 36kW models.

For a maximum 3% voltage drop on 6mm² AC cable, the manual gives cable lengths of 245m (25kW) down to 170m (36kW). Solis publishes a CEI 0-21 certificate for Italy, and EN 50549-1/-10, VDE-AR-N 4105, TOR Erzeuger and IEC/EN 62109 certificates for the series.

Monitoring and settings

There is no keypad display: the inverter has LED indicators and is commissioned from a phone over Bluetooth with the SolisCloud app, which sets the grid code, power factor, export limit, AFCI and the logic interface (DRM) used by some European utilities. Of the two independent RS485 ports, one serves the meter or, alternatively, a third-party controller, and the other links inverters or an EPM unit; remote monitoring needs an optional Wi-Fi or GPRS data logger.

Questions and answers