Solis S5-GC50K50kW three-phase grid-tied string inverter, 5 MPPT

Overview

The S5-GC50K is the 50kW, five-tracker model of the Solis S5-GC(50-60)K three-phase string inverter series for commercial and agricultural roofs. Each of the five MPP trackers takes two strings at up to 32A, between 180V and 1000V, with full-load MPPT from 550V to 850V and a maximum input of 1100V. Maximum output is 55kVA at 98.7% peak and 98.3% European efficiency. The 53.7kg IP66 unit has a C5 anti-corrosion rating, and the manual specifies a 100A AC protection device.

• 50kW with 5 MPPT, 60kW with 6 MPPT
• 32A per tracker, two strings each
• 1100V max. input, 180–1000V MPPT range
• Max. efficiency 98.7%, EU efficiency 98.3%
• Night SVG and optional night-time PID recovery
• IP66 housing with C5 anti-corrosion rating

How it works

The S5-GC(50-60)K is a transformerless three-phase inverter for grid-connected PV plants on commercial, industrial and farm buildings. The S5-GC50K has five MPP trackers and the S5-GC60K six, each accepting two strings at up to 32A, so several roof faces or orientations can be handled by a single unit. Trackers operate from 180V to 1000V, with full-load MPPT between 550V and 850V and a maximum input of 1100V.

Both models can deliver 10% more than their rated power, up to 55kVA and 66kVA. The grid connection is 3/N/PE at 220/380V or 230/400V and 50Hz or 60Hz, with a power factor adjustable from 0.8 leading to 0.8 lagging. Night-time self-consumption is below 1W.

Key features

Every string is monitored, and an I-V curve scan helps to locate faulty, soiled or shaded modules; a multi-peak scan keeps tracking stable under partial shading. DC and AC type II surge protection and a DC switch are integrated. AFCI 2.0 arc-fault detection and night-time PID recovery are factory options. Solis notes that with PID recovery fitted, the night-time reactive power (SVG) function and negative grounding cannot be used.

The inverter works with an optional three-phase smart meter, installed on the grid side or the load side, for export power management; 24-hour consumption monitoring requires the meter on the grid side. The 16-pin COM port also provides RS485 daisy-chaining between inverters and a DRM or logic interface for an external utility relay where local rules require one.

Installation and compatibility

The IP66 housing measures 691×578×338mm and weighs 53.7kg; cooling is by intelligent redundant fans and the typical noise level is below 55dB(A). It mounts on a wall or a metal rack, vertically or tilted back by up to 15°, with at least 500mm between inverters and other equipment and the bottom at least 500mm above the floor. The manual describes the series for commercial and industrial use only.

AC wiring uses copper cable of 10–70mm² (35mm² recommended) on M8 crimp terminals. The manual specifies an AC protection device of 100A for the S5-GC50K and 125A for the S5-GC60K. For Italy Solis publishes CEI 0-21 and CEI 0-16 declarations and certificates; EN 50549-1, EN 50549-2 and VDE-AR-N 4105 certificates are also available.

Monitoring and settings

Local settings are made on the LCD with capacitive touch buttons, including grid standard, active and reactive power, export limit and the AFCI function. RS485 and USB are standard. Remote monitoring in SolisCloud needs an optional Wi-Fi or GPRS data logging stick, or a one-to-many data logger on the RS485 bus, which can also feed third-party SCADA or plant controllers.

Questions and answers