Solis S5-GR3P4K4kW three-phase grid-tied string inverter, 2 MPPT

Overview

The S5-GR3P4K is the 4kW model of the Solis S5-GR3P(3-20)K series, aimed at small three-phase homes where a single-phase inverter would unbalance the supply. Its two MPP trackers take one string each at up to 16A, within a 160–1000V window, and Solis recommends a PV array of up to 6kW. The inverter delivers up to 4.4kVA at 98.3% peak and 97.7% European efficiency. Natural convection cooling keeps it below 30dB(A), it weighs 16.5kg, and the manual lists a 20A AC protection device.

• 3 to 20kW, 3/N/PE 380/400V
• 2 MPPT, 160–1000V, 1100V max. input
• PV array up to 150% of rated power
• Max. efficiency up to 98.7%
• Export control and 24h consumption monitoring
• IP66, 310×563×219mm

How it works

The S5-GR3P(3-20)K is a transformerless three-phase string inverter for grid-connected PV systems on homes, farms and small businesses. All models have two MPP trackers with a wide 160–1000V MPPT window, a 180V start-up voltage and a maximum input of 1100V. Models up to 10kW take one string per tracker at 16A; the 12–20kW models take two strings per tracker at 32A.

Solis recommends a PV array of 1.5 times the rated AC power, for example 12kW on the 8kW model and 30kW on the 20kW model. Maximum AC output is 10% above the rated power. The grid connection is 3/N/PE at 220/380V or 230/400V, 50Hz or 60Hz, with an operating frequency range of 45–55Hz or 55–65Hz.

Key features

The inverters integrate DRM and export power control: with an optional three-phase smart meter, either a direct-connection meter up to 80A or a CT meter, they limit feed-in to a set value or record consumption around the clock. Solis lists an adaptive function for weak grids and a multi-peak scan for partly shaded strings.

AFCI 2.0 arc fault detection is optional and a DC switch is integrated. Lower-power models are cooled by natural convection and run below 30dB(A); the larger models use intelligent redundant fans with noise below 60dB(A). Night-time self-consumption is under 1W.

Installation and compatibility

All models share a 310×563×219mm IP66 housing weighing about 17–21kg, mounted vertically or tilted back by up to 15°, with 500mm of clearance between inverters, to other objects and to the ground. The AC connection uses a quick-connection plug. Solis gives the AC protection device per model in the manuals, from 20A for the smallest models to 40A for the 17kW and 20kW versions.

For Italy, Solis publishes a CEI 0-21 declaration of conformity and certificate for the S5-GR3P(3-20)K. EN 50549-1 and VDE-AR-N 4105 certificates are also available, together with an IEC/EN 62109-1/-2 safety certificate and the EU declaration of conformity. The grounding cable on the housing should be at least 6mm², as stated in the manual.

Monitoring and settings

Settings are made on the LCD display with four keys, including grid standard, power limits, export management and AFCI. RS485 and digital inputs and outputs are standard; for remote monitoring in SolisCloud a Wi-Fi or GPRS data logging stick is added to the COM port. Solis publishes separate user manuals for the 3–13kW and 15–20kW models.

Questions and answers