SolarMax
20C · 25C · 30C · 35C · 50C · 80C · 100C
Solis: S5-GR3P / S5-GC / S6-GCTechnical selection for existing PV plants
Revamping photovoltaic plants
PV plant revamping means renewing obsolete or underperforming equipment without treating the intervention as a simple model swap. PnP helps O&M teams, asset managers, installers and engineering firms review electrical data, communications and physical constraints to select and supply a technically documented solution.
More than 20 years of experience
Selection for professionals
Validated against current documentation
INSTALLED FLEET 2004–2009
Inverters from 2008 no longer fail as a model number: they fail as an architecture
SolarMax, Sunways, Conergy, SMA and Power-One/Aurora belong to the technical landscape of many mature plants. The exact nameplate and the real diagram prevail: similar power does not mean a direct replacement.
Documented references from the 2006–2008 generationSunways
NT 8000 · NT 10000 · NT 11000 · NT 12000
Solis: S5-GR3PConergy
WR 1700–5900 · IPG 4000/5000 · IPG 8T/11T/15T · IPG central 60K/80K/100K/110K/280K/300K
Solis: S6-GR1P / S5-GR3P / S6-GCSMA
Sunny Boy · SMC · Sunny Central 100/250/500
Solis: S6-GR1P / S5-GR3P / S6-GCPower-One / Aurora
PVI 3.0–12.5 · central 55–330 kW
Solis: S6-GR1P / S5-GR3P / S6-GCVerified period sources: 2006 SolarMax C, 2006/2008 Sunways NT and official 2007–2008 Conergy Central Power/IPG documents. The Sierra Nevada Spanish reference is in Conergy’s official brochure; this remains short of an exhaustive census of Spain.
More families to look for on the nameplate
These ranges occur in the universe of older plants and adjacent generations. Each is linked to the Solis family assessed first, never to an automatic equivalence.
REPLACEMENT MATRIX
Legacy inverter → Solis candidate to assess
The matrix starts the diagnosis. Compatibility is closed with minimum-temperature Voc, currents, MPPTs, strings, grid, transformer, earthing, communications and space.
12 / 12
| Legacy equipment | Known profile | Solis starting point | Critical condition |
|---|---|---|---|
| Legacy equipmentSolarMax 20C / 25C / 30C / 35C | Known profile20–35 kW · transformer central inverter · 3×400 V · MPPT 430–800 V | Solis starting pointS5-GR3P20KS5-GC25K30K-5G36K-5G | Critical conditionConvert the common bus into MPPT inputs and review galvanic isolation. |
| Legacy equipmentSolarMax 50C / 80C / 100C | Known profile50/80/100 kW · transformer central inverter · 3×400 V · common DC bus | Solis starting pointS6-GC3P50KS6-GC80KS6-GC100K | Critical conditionSplit strings, protection and communications; the old transformer is not inherited automatically. |
| Legacy equipmentSunways NT 8000 / NT 10000 | Known profile8/10 kW · three-phase 400 V · 3 MPPT · 350–750 V · max. 850 V | Solis starting pointS5-GR3P8KS5-GR3P10K | Critical conditionThe 10 kW Solis has 2 MPPTs: regroup only if orientations and currents allow it. |
| Legacy equipmentConergy WR 1700–5900 / IPG 4000–5000 | Known profileWR and IPG 4/5 kW · single-phase 230 V; IPG 5000 allows up to 800 V DC | Solis starting pointS6-GR1P4–5KS5-GR3P5K | Critical conditionUse S6-GR1P only if Voc ≤600 V and MPPT ≤520 V; otherwise re-string or redesign to three-phase. |
| Legacy equipmentConergy IPG 8 T / 11 T / 15 T | Known profile8/11/15 kW · three-phase · insulation and residual-current monitoring | Solis starting pointS5-GR3P8KS5-GR3P12KS5-GR3P15K | Critical conditionCheck the model-specific 350/400/450–800 V MPPT range, strings, current and grid. |
| Legacy equipmentConergy IPG central 60K / 80K / 100K / 110K | Known profile54/72/90/100 kW AC · three-phase central · MPPT 493–780 V · max. 965 V | Solis starting pointS6-GC3P50KS6-GC80KS6-GC100K | Critical conditionLegacy AC output and transformer do not necessarily match a 400 V Solis grid. Redesign DC, AC, transformer and control. |
| Legacy equipmentConergy IPG central 280K / 300K · bloque ≈500 kW | Known profileIPG 280K: 250 kW AC with isolation transformer; IPG 300K: 270 kW AC without LV transformer and for an external MV transformer | Solis starting point2–3× S6-GC125K4× S6-GC125K para bloque ≈500 kW | Critical conditionIPG 280K (196–253 V) and IPG 300K (126–179 V) require different designs. For 250–270 kW or a block around 500 kW, size from actual DC/AC power. |
| Legacy equipmentSMA Sunny Boy / Sunny Mini Central 2.5–8 kW | Known profileSB/SMC 2.5–8 kW · different single-phase and high-voltage families | Solis starting pointS6-GR1P2.5–6KS5-GR3P5KS5-GR3P10K | Critical condition“5000” does not define phases or scale; separate SB/SMC 5000 from Sunny Central 500. |
| Legacy equipmentSMA Sunny Central 100 / 250 / 500 | Known profile100/250/500 kW central inverters · centralised architecture | Solis starting pointS6-GC100K2× / 4× S6-GC125K | Critical conditionCentral-to-string change: redesign DC distribution, AC, control, protection and unit count. |
| Legacy equipmentPower-One Aurora PVI 3.0–6.0 | Known profilePVI 3.0/3.6/4.2/5.0/6.0 · small power | Solis starting pointS6-GR1P3KS6-GR1P5KS6-GR1P6K | Critical conditionValidate string voltage and phase; old models do not share one DC window. |
| Legacy equipmentPower-One Aurora PVI 8.0 / 10.0 / 12.5 | Known profilePVI 8.0/10.0/12.5 · 400 V three-phase; PVI 10/12.5 with 2 MPPT and max. 850 V | Solis starting pointS5-GR3P8KS5-GR3P10KS5-GR3P13K | Critical conditionCheck MPPT current: PVI 10 allowed 18 A per channel. |
| Legacy equipmentPower-One Aurora PVI central 55–330 kW | Known profilePVI central 55–330 kW · central DC bus and control | Solis starting pointS6-GC50KS6-GC100KS6-GC125K / multi-inverter | Critical conditionSet the Solis count from real DC and AC limits, not aggregate power alone. |
Candidate does not mean plug-and-play. Older central plants usually require DC redistribution and a new review of insulation, protection, communications and control.
Starting point
Start with the existing plant, then choose the new equipment
Revamping is often presented as a product replacement. In a real plant, the decision must start from the existing architecture and its electrical, mechanical and control constraints.
Obsolete or failed inverter
Compare grid voltage, AC power, PV array, MPPTs, strings, protection and plant control.
Degraded monitoring or communications
Review protocols, datalogger, sensors, PPC/SCADA, meters and export-control requirements.
No direct replacement
Check the existing array against voltage, current, minimum temperature, space and intervention strategy.
Technical checklist
Information needed before proposing an alternative
| Area | Minimum information | Why it matters |
|---|---|---|
| AreaExisting equipment | Minimum informationExact make and model, AC power, phases, grid voltage and firmware. | Why it mattersEstablishes the comparison point and avoids assuming equivalence from nominal power. |
| AreaPV array | Minimum informationModules per string, number of strings, Voc, Isc, orientation and minimum temperature. | Why it mattersAllows MPPT windows, maximum voltage and input current to be checked. |
| AreaElectrical architecture | Minimum informationDC/AC protection, transformer, earthing, diagram and connection point. | Why it mattersDefines required changes and grid constraints. |
| AreaControl and communications | Minimum informationDatalogger, meters, sensors, PPC/SCADA, protocols and export-control requirement. | Why it mattersDetermines which integrations may remain or need adaptation. |
| AreaSite and intervention | Minimum informationIndoor or outdoor, space, cooling, access and available shutdown window. | Why it mattersAffects format, mounting, heat dissipation and intervention planning. |
Working method
A documented decision in four steps
Inventory
Collect references, diagrams, alarms, history and useful plant photographs.
Compatibility
Verify DC and AC limits, MPPTs, grid, protection, communications and space.
Alternatives
Compare documented options without promising a universal or direct replacement.
Intervention
Define equipment, accessories, settings, tests and commissioning requirements.
REVAMPING LAYER
Do not replace only the inverter: restore diagnosis, protection and data
A defensible revamping project combines conversion with DC boxes, insulation testing, PID mitigation and fleet monitoring.
Combiner / anti-combiner box
In a central-to-string conversion, an engineered DC redistribution box can split the common bus towards several MPPTs. Current, fuses, isolation, SPD, polarity and, where required, string monitoring must be designed.
Request box engineering →Ground-fault location
The Seaward PV1525 photovoltaic tester supports insulation diagnosis on PV systems. Qualified personnel only, following the manual, lockout procedure and actual plant voltage.
View the PV1525 tester →Anti-PID by module and polarity
APID boxes for P-Type and APID-NG for N-Type are not universal. Module technology, polarity, earthing, MPPTs and new-inverter topology must be validated.
View Anti-PID options →Solar-Log to restore visibility
Solar-Log can consolidate old and new inverters, meters and sensors in mixed fleets. Check the exact driver, protocol, interfaces, licences and PPC/SCADA requirements first.
Read Solar-Log manuals →Solis functions that add diagnosis
S6-GC 40–60 kW and 80–125 kW families document string and I/V-curve monitoring; the 80–125 kW range adds real-time PV insulation detection. PID recovery is optional by configuration.
View Solis S6-GC100K →Related resources
Continue with the route you need
Frequently asked questions
PV revamping: answers for professionals
What is photovoltaic plant revamping?
It is the renewal of equipment or subsystems in an existing plant to address obsolescence, faults or operational constraints. The solution must respect the actual plant design and be technically validated.
Can any current inverter replace an older model?
No. Matching nominal power does not guarantee compatibility. The PV array, MPPTs, voltage and current, grid, protection, communications, space and control strategy must be reviewed.
What information is needed to assess the change?
At minimum: equipment reference, single-line diagram, modules and strings, Voc and Isc, grid voltage, protection, communications, alarms, photographs and shutdown constraints.
Must strings be redesigned when replacing the inverter?
Not always. They may remain only if array voltage and current stay within the windows and limits of the new equipment under the site’s actual conditions.
Can the existing monitoring system be retained?
It depends on protocols, dataloggers, sensors, meters and plant control. Communications compatibility must be checked separately from electrical compatibility.
What does Plug & Play Energy contribute?
Technical selection support and equipment supply for professionals, comparing alternatives against current documentation. Final engineering and approval remain with the project’s responsible technical team.
Editorial and technical review: Plug & Play Energy team · 11 September 2026. Final selection is validated against current documentation and the actual data of each plant.
Bring the plant data; we will help you structure the alternative
Include the existing reference, diagram, strings, grid voltage, communications, alarms and shutdown constraints to speed up the review.