Process / SOP • Vertical-solar Balance-of-System (BoS) • Corridor CN → SN
This Standard Operating Procedure (SOP) defines how TradVolt service engineers perform an I-V (current–voltage) curve trace test on individual PV strings within a China-to-Senegal vertical-solar BoS corridor. The procedure supports commissioning verification, warranty claims, and post-event diagnostics. Step sequence, document checklist, and trade-compliance notes are provided as field-ready references; rates and duties are deliberately marked as placeholders pending authoritative lookup.
The purpose is to establish a repeatable method for tracing the I-V characteristic of each photovoltaic string in service, comparing measured values against manufacturer baseline, and producing traceable evidence for the asset record. The scope covers low-voltage DC-side string testing using a portable curve tracer, performed by trained field service personnel on operating plants or at incoming inspection.
| Step # | Action | Owner | Input doc | Output doc | Done-when |
|---|---|---|---|---|---|
| 1 | Receive work order and confirm site, inverter, string count, and access window. | Service Coordinator | WO (Work Order) | Acknowledged WO log | WO logged in CMMS with site code, expected string count, and visit date. |
| 2 | Review site safety plan, isolation scheme, and PPE requirements; brief the team. | Site Safety Officer | Site Safety Plan | Signed toolbox-talk sheet | All crew sign toolbox-talk; LOTO kit inspected. |
| 3 | Calibrate the I-V tracer against a reference cell or PV calibrator; record values. | Field Engineer (LE) | Tracer calibration log (last entry) | Updated calibration record | Calibration record shows date, reference values, and engineer signature. |
| 4 | Isolate the target string at combiner; verify zero energy with a DC voltage tester. | Field Engineer (LE) | Single-line diagram | Isolation tag placed | Voc reading ≤ 5 V at string terminals; lock and tag applied. |
| 5 | Connect tracer leads; capture irradiance and module temperature inputs. | Field Engineer (LE) | Module datasheet (STC) | Raw trace file (.csv/.trc) | Trace file saved with timestamp, irradiance W/m², and cell temperature °C. |
| 6 | Run the I-V sweep and validate shape (Voc, Isc, Vmpp, Impp, fill factor). | Field Engineer (LE) | Raw trace file | Validated trace sheet | Key points recorded; anomalies flagged if deviation > set tolerance. |
| 7 | Re-energize the string; confirm DC operating voltage on inverter string input. | Field Engineer (LE) | Validated trace sheet | Inverter readout note | Inverter recognises string; telemetry reflects expected Vdc range. |
| 8 | Repeat Steps 4–7 for each string in the inspection batch. | Field Engineer (LE) | String list | Batch of trace sheets | All strings in batch tested; missing strings justified in comments. |
| 9 | Sign off the test report; attach traces and photos to the asset record. | Field Engineer (LE) + Service Coordinator | Batch of trace sheets | Signed PDF test report | Report uploaded to CMMS; QA review completed. |
| 10 | Close ticket and notify the client with findings summary. | Service Coordinator | Signed PDF test report | Client email + CMMS ticket closed | Client acknowledges receipt; ticket status set to "Closed". |
WO_[SiteCode]_[YYYYMMDD].pdf — Work order file.SafetyPlan_[SiteCode]_v[XX].pdf — Site safety and LOTO plan.ToolboxTalk_[YYYYMMDD].pdf — Signed toolbox-talk sheet.IVTracer_CalLog_2026.xlsx — Tracer calibration log.SLD_[SiteCode].pdf — Single-line diagram for isolation reference.ModuleDatasheet_[Model].pdf — OEM module datasheet (STC values).Trace_String[NN]_[YYYYMMDD].csv — Raw I-V trace data per string.TestReport_[SiteCode]_[YYYYMMDD].pdf — Final signed report.| Phase | Indicative duration | Dependencies |
|---|---|---|
| Pre-mobilisation (Steps 1–3) | 1 working day (indicative) | Client WO, tracer availability, OEM datasheet. |
| On-site execution (Steps 4–8) | ~15–20 minutes per string (indicative) | Weather window ≥ 400 W/m² irradiance (indicative), safe access. |
| Reporting & close-out (Steps 9–10) | 1 working day (indicative) | QA review, client contact, CMMS availability. |
| Total field footprint | ~8 h on site for a 24-string batch (indicative) | Includes travel between combiner boxes; not measured. |
All durations are indicative and depend on site layout, string count, and weather. Actual times are recorded in the CMMS time-sheet per visit.
| Slot | Value | Status |
|---|---|---|
| Mobilisation fee (per site visit) | indicative | UNCERTAIN — quote on RFQ |
| Per-string test labour | indicative | UNCERTAIN — quote on RFQ |
| Tracer rental / depreciation | indicative | UNCERTAIN — quote on RFQ |
| Report preparation | indicative | UNCERTAIN — quote on RFQ |
| Cross-border logistics (CN → SN) | indicative | UNCERTAIN — depends on Incoterms® 2020 selection and FIATA documents. |
| Item | HS code | Duty rate | Source / portal |
|---|---|---|---|
| PV modules (crystalline silicon) | PENDING — lookup | PENDING — lookup | World Customs Organization HS nomenclature; national tariff portals. |
| Electrical measuring instruments (I-V tracer, multimeter) | PENDING — lookup | PENDING — lookup | World Customs Organization HS nomenclature; national tariff portals. |
| DC isolators / combiners (BoS parts) | PENDING — lookup | PENDING — lookup | World Customs Organization HS nomenclature; national tariff portals. |
Disclaimer: HS classifications and applicable duty/VAT rates for the corridor CN → SN must be verified against the official customs portal of each jurisdiction at the time of shipment. TradVolt does not hardcode duty rates; the placeholders above are intentional and must be resolved by a licensed customs broker or the importer of record before any commercial invoice is issued.
Need this SOP executed on your site? Submit your string count, site location, and target visit window. TradVolt service coordinators will respond.
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