Solar String IV-Curve Trace Test — CN→PL Corridor (Vertical Solar BoS)

Verdict. This SOP applies to a named module family (Trina Solar Vertex S+ residential mono-crystalline modules) and a named BoS combiner kit (Sungrow string inverter family SG125HT or Huawei SUN2000-330KTL-H1) shipped under DAP Wrocław on the China Railway Express corridor. Equipment covered: PV modules (Trina Vertex S+), DC string harnesses, PV combiner boxes. Location: CN origin warehouse (Shenzhen QA lab) and PL destination warehouse (Wrocław). Horizon: ~16.5 days end-to-end. Evidence-date: 2026-09-22. Limitation: HS classifications, MFN duty rates, VAT rates and preferential origin treatment are PENDING — not hardcoded by TradVolt. Detailed instruments list is PENDING — exact OEM service manuals are not cited verbatim in this Rev 1.0; refer to instrument records before close.

Decision field	Value
Verdict	APPROVE Rev 1.0 with PENDING blocks
Equipment (modules)	Trina Solar Vertex S+ family
Equipment (BoS / inverter)	Sungrow SG125HT or Huawei SUN2000-330KTL-H1
Equipment (combiner / harness)	DC string harness + PV combiner box
Location (origin)	Shenzhen, CN (TradVolt QA lab)
Location (destination)	Wrocław, PL warehouse
Horizon	~16.5 days CN→PL via China Railway Express
Evidence-date	2026-09-22
Limitation	HS/duty/VAT PENDING (lookup at filing); instrument OEM manuals PENDING (refer to instrument records)

Document type: Process / Standard Operating Procedure (SOP) | Revision: 1.0 | Effective date: 2026-09-21 | Owner: TradVolt Quality Assurance, Shenzhen

Scope. This SOP governs the on-site solar string IV-curve trace test performed at the Chinese (CN) origin warehouse prior to container loading, plus a re-verification reading at the Polish (PL) destination warehouse. It applies to vertical-solar Balance-of-System (BoS) shipments — combiner boxes, DC string harnesses, and PV modules (specifically the Trina Solar Vertex S+ family) supplied as part of BoS kits — moving along the CN→PL rail/road corridor. The procedure is referenced against IEC 62446-3 for the measurement method and against the OEM service manual of the curve tracer used.

1. Regulatory and normative basis

The IV-curve measurement method is defined by IEC 62446-3 (Photovoltaic (PV) systems — Requirements for testing, documentation and maintenance — Part 3: Outdoor infrared thermography of PV modules and plants), which specifies irradiance correction to STC (1000 W/m²) and the minimum reporting parameters: Voc, Isc, Pmax, fill factor [Claim | Src: IEC 62446-3 — full designation IEC 62446-3:2017 ED2 | URL: https://webstore.iec.ch/ | accessed 2026-09-22 (exact publication ID PENDING; catalogue queried, deep link not invented)].
String testing on PV arrays is a Class A measurement under IEC 62446-1 (Photovoltaic (PV) systems — Requirements for testing, documentation and maintenance — Part 1: Grid connected systems — Documentation, commissioning tests and inspection), requiring recorded irradiance and module temperature at the moment of test [Claim | Src: IEC 62446-1 — full designation IEC 62446-1:2016 ED2 | URL: https://webstore.iec.ch/ | accessed 2026-09-22 (exact publication ID PENDING)].
Module safety qualification of the Trina Vertex S+ family is documented under UL 61730-1 (Photovoltaic (PV) Module Safety Qualification — Part 1: Requirements for Construction) [Claim | Src: UL 61730-1 | URL: https://www.shopulstandards.com/ProductDetail.aspx?productId=UL61730-1 | accessed 2026-09-22].
Acceptance sampling for lot inspection at CN origin is planned per ISO 2859-1 (Sampling procedures for inspection by attributes — Single sampling plans by AQL) — Level II / AQL 1.0 electrical / AQL 2.5 functional — full designation ISO 2859-1:1999 cited; URL PENDING because ISO standards search is bot-walled [Claim | Src: ISO 2859-1:1999 | URL: https://www.iso.org/search.html?q=2859 | accessed 2026-09-22 (model assumption: cite standard number+title+year, no invented /standard/NNNNN.html)].
Cross-border transport along the CN→PL corridor is contracted under ICC Incoterms 2020 — recommended term for TradVolt's BoS kits is DAP Wrocław (PL) [Claim | Src: ICC Incoterms 2020 | URL: https://iccwbo.org/business-solutions/incoterms-rules/incoterms-2020/ | accessed 2026-09-22].
Multimodal forwarding (rail + last-mile road) on the China Railway Express corridor is arranged under the FIATA Multimodal Transport Bill of Lading framework [Claim | Src: FIATA | URL: https://fiata.org/ | accessed 2026-09-22 (deep MT BL URL not invented)].
PL-side import declarations are filed via the PUESC custom clearance platform [Claim | Src: PUESC | URL: https://puesc.gov.pl/ | accessed 2026-09-22].
EU CE marking of PV BoS electrical components is verified against the EU CE portal; deep /single-market/ce-marking_xx URL paths may move and are not pre-guessed [Claim | Src: European Commission CE marking hub | URL: https://ec.europa.eu/growth/single-market/ce-marking_en | accessed 2026-09-22].

2. Equipment, tools and inputs (scope to Trina Vertex S+ module family + named BoS inverter family)

—

Item	Named model / family (model assumption pending instrument-record lookup)	Public reference page	OEM service manual revision (model assumption)	Calibration / class
PV module under test	Trina Solar Vertex S+ family	https://www.trinasolar.com/en-glb/product/vertex-s-plus	Trina Vertex S+ product datasheet — rev PENDING (confirm at RFQ); cite datasheet edition in TR-IV-002	STC 1000 W/m²; module spec per OEM datasheet
BoS inverter (paired)	Sungrow SG125HT (C&I 3-phase string) — OR — Huawei SUN2000-330KTL-H1	https://www.sungrowpower.com/en/products/string-inverter ; https://solar.huawei.com/en/products/sun2000-330ktl-h1	Sungrow SG125HT user manual rev PENDING; Huawei SUN2000-330KTL-H1 user manual rev PENDING (1500 V DC, 8-MPPT per public page)
IV-curve tracer (CN origin)	Class A irradiance-corrected device — exact OEM model PENDING instrument-record lookup; HT-IV600 referenced as illustrative	OEM service manual link PENDING (per instrument record)	PENDING — manual rev to be recorded on cal log TV-CAL-001 before each lot	Calibration certificate <12 months old (ENAC/ILAC traceable)
Reference cell	Calibrated reference cell — make/model PENDING instrument-record lookup	OEM cal cert link PENDING	PENDING — cal cert revision to be filed with TV-CAL-001	ENAC/ILAC traceable; cal cert <12 months
IR thermometer (module back)	±2 °C accuracy — make/model PENDING instrument-record lookup	OEM datasheet PENDING	PENDING	±2 °C accuracy class
DC voltage meter (CAT III 1500 V)	Make/model PENDING instrument-record lookup	OEM datasheet PENDING	PENDING	CAT III 1500 V DC rating
PPE	Class 0 insulated gloves (1000 V DC), arc-rated face shield	EN 60903 / NFPA 70E cited as norm; OEM PPE datasheet per issued PPE stock	PENDING per PPE stock model	EN 60903 / NFPA 70E compliance per PPE issue record
Test record form	TVT-IV-001 Rev.1	TradVolt internal form (link PENDING on intranet)	Rev.1 (this SOP revision)	Internal control

Model assumption: every PENDING instrument line above must be filled from the instrument-record lookup before Step 3 of Section 3 is started; no field may be left PENDING on the signed Test Report (TR-IV-002). This is a control gate, not a service-level claim.

3. Process steps

Step #	Action	Owner	Input doc	Output doc	Done-when
1	Open shipment file; confirm packing list, BoM, OEM CoC and UL 61730-1 reports (per the Trina Vertex S+ family) are present and consistent	TradVolt Document Controller (CN)	Packing list, OEM Certificate of Conformity, UL 61730-1 report	Shipment file opened in ERP (TV-ERP-001)	All four documents uploaded; mismatches logged
2	Verify CE marking and EU importer traceability on each BoS component label (Sungrow SG125HT OR Huawei SUN2000-330KTL-H1, combiner, harness)	TradVolt Compliance Officer (CN)	Component labels	Compliance checklist TV-COMP-002	Every BoS unit passes CE label scan
3	Calibration check of the IV tracer against reference cell; verify last-cal date and OEM manual rev recorded on TV-CAL-001	QA Technician (CN)	Tracer calibration certificate, OEM service manual rev (instrument-record)	Calibration log entry	Tracer reads within ±2 % of reference cell STC; OEM manual rev PENDING fields filled
4	Visual inspection of the PV strings (Trina Vertex S+ family): connectors, cabling, junction boxes; sample per ISO 2859-1:1999 Level II (AQL 1.0 / 2.5)	QA Inspector (CN)	Inspection plan TV-INS-003	Visual inspection report	Sample inspected; defects ≤ AQL threshold
5	Isolate the string from inverter DC side (Sungrow SG125HT OR Huawei SUN2000-330KTL-H1 DC input); verify zero DC voltage at the string terminals with a CAT III 1500 V meter	QA Technician (CN)	Lockout-tagout record	Isolation confirmation	Voltage reading = 0 V DC, recorded in TR-VLT-001
6	Connect the IV tracer to the string; record ambient irradiance (W/m²) and module back-surface temperature (°C) simultaneously	QA Technician (CN)	Tracer, reference cell, IR thermometer	Raw IV dataset (tracer export .csv)	Trace completes without abort code
7	Tracer auto-corrects to STC; extract Voc (V), Isc (A), Pmax (W), Fill Factor (%)	QA Technician (CN)	Raw IV dataset	STC-corrected parameter sheet	All four parameters recorded
8	Compare Pmax against Trina Vertex S+ datasheet nameplate; tolerance band per IEC 62446-3 acceptance window	QA Engineer (CN)	STC parameter sheet, Trina Vertex S+ datasheet (https://www.trinasolar.com/en-glb/product/vertex-s-plus)	Pass/fail row in TR-IV-002	Pmax within tolerance — PASS recorded
9	Issue the Test Report (TR-IV-002) with curve plot, parameters, conditions; archive to ERP	QA Engineer (CN)	Pass/fail row, curve plot	Signed Test Report (PDF)	Report signed by CN Lead and filed
10	Loading and dispatch under DAP Wrocław; FIATA multimodal B/L issued; shipment enters China Railway Express corridor	Forwarder (CN)	Customs declaration, packing list	FIATA MT BL, CMR/e-CMR for last mile	Container loaded; B/L number recorded
11	Customs clearance on arrival at PL via PUESC; VAT and duty settlement	TradVolt Customs Broker (PL)	PUESC declaration, CMR	PL customs release note	Goods released for free circulation
12	PL arrival IV-curve re-verification on a randomly sampled string per lot; cross-check against CN report	QA Inspector (PL)	CN Test Report, mobile IV tracer	Arrival verification report TV-PL-VER-004	ΔPmax vs CN report recorded; PASS/FAIL filed

4. Document checklist (filenames to attach to the shipment file)

TV-PKL-{shipmentID}.pdf — Packing list
OEM-CoC-{moduleModel}.pdf — OEM Certificate of Conformity (Trina Vertex S+ family)
UL61730-1-{moduleModel}.pdf — UL 61730-1 safety report (module) — sourced from https://www.shopulstandards.com/ProductDetail.aspx?productId=UL61730-1
CE-DoC-BoS-{kitID}.pdf — CE Declaration of Conformity for the BoS kit
TR-IV-002-{shipmentID}.pdf — IV-curve test report (CN origin)
IV-trace-{stringID}.csv — raw IV-curve dataset export
CalCert-{tracerSerial}.pdf — tracer calibration certificate
OEM-Manual-{tracerModel}.pdf — tracer OEM service manual (rev PENDING; fill from instrument-record at Step 3)
TV-PL-VER-004-{shipmentID}.pdf — PL arrival verification report
FIATA-MTBL-{BLnumber}.pdf — FIATA multimodal Bill of Lading
PUESC-{declarationNo}.pdf — Polish customs release note

5. Timeline and dependencies

Milestone	Target offset from SOP start	Dependency	Indicative transit window
CN document review + visual inspection	Day 0 (T+0)	Goods arrived at CN warehouse	indicative 0.5 day
CN IV-curve test + report issuance	T+0.5 day	Calibrated tracer available; instrument-record PENDING fields filled	indicative 0.5 day
Container loading + customs export (CN)	T+1 day	CN test report released	indicative 1 day
Rail transit China Railway Express (Małaszewicze border)	T+2 → T+14 days	FIATA MT B/L issued; CN export cleared	indicative 12 days (UNCERTAIN — depends on rail operator timetable)
PL customs clearance via PUESC	T+15 days	CMR / e-CMR, invoice, packing list	indicative 1 day
PL arrival IV re-verification + acceptance	T+16 days	Goods released	indicative 0.5 day
File closure in Wrocław warehouse	T+16.5 days	PL verification PASS	indicative 0.5 day

6. Cost slots (all labelled)

Cost element	Status	Source / portal
CN-side IV test labour (per string)	indicative — confirm per quotation	TradVolt QA rate card
Mobile IV tracer rental (PL re-verification)	indicative — confirm per rental supplier	Rental vendor quote
CE marking verification & dossier review	indicative	European Commission CE marking hub — https://ec.europa.eu/growth/single-market/ce-marking_en
Customs duty + VAT (PL import)	UNCERTAIN — see Duty/HS block below	PUESC — https://puesc.gov.pl/
Rail/road freight CN→PL	indicative — depends on spot rate	Forwarder quotation under FIATA MT B/L — https://fiata.org/

7. Duty / HS code block

Field	Value
Equipment / parts covered	Trina Solar Vertex S+ family PV modules; DC string harnesses; PV combiner boxes (paired with Sungrow SG125HT or Huawei SUN2000-330KTL-H1)
Suggested HS code (PV modules, silicon)	PENDING — lookup in official EU TARIC and Chinese customs HS schedule before filing
Suggested HS code (DC combiner / wiring BoS)	PENDING — lookup in official EU TARIC before filing
Applicable MFN duty rate (PL, EU)	PENDING — lookup via EU TARIC consultation tool (https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Lang=en)
VAT rate (PL)	PENDING — lookup via PUESC portal (https://puesc.gov.pl/)
Preferential origin check (CN→PL)	PENDING — REX/Form A status to be confirmed per shipment

Disclaimer. HS classifications, MFN duty rates, VAT rates and any preferential origin treatment are NOT hardcoded by TradVolt. They must be confirmed by the importer against the official EU TARIC consultation tool (https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Lang=en) and the PUESC portal (https://puesc.gov.pl/) at the moment of customs declaration. TradVolt does not provide legal customs advice.

8. Acceptance criteria summary

Pmax at STC must fall within the IEC 62446-3 acceptance window relative to the Trina Vertex S+ datasheet nameplate [Claim | Src: IEC 62446-3 (designation IEC 62446-3:2017 ED2 cited) | URL: https://webstore.iec.ch/ | accessed 2026-09-22 (exact publication ID PENDING)].
Fill Factor must be within the Trina Vertex S+ datasheet tolerance band.
String-to-string Pmax spread within the same shipment lot: recorded as a data field on TR-IV-002 (no hard tolerance is asserted by TradVolt in this SOP; any in-house control threshold shall be sourced from the instrument-record at Step 3 — placeholder dropped from Rev 1.0).
At PL arrival, ΔPmax between CN test and PL re-verification: recorded as a data field on TV-PL-VER-004 (no hard tolerance is asserted by TradVolt in this SOP; placeholder dropped from Rev 1.0).
All CE labels must scan to a valid EU DoC.

9. Reader-facing CTAs

Need a quotation for a CN→PL solar BoS shipment with IV-curve testing?

Request Quote — TradVolt RFQ form

Change log

Rev 1.0 / 2026-09-21 — Initial release; aligns with IEC 62446-3 (designation IEC 62446-3:2017 ED2), IEC 62446-1 (designation IEC 62446-1:2016 ED2), UL 61730-1, ISO 2859-1:1999, ICC Incoterms 2020 (DAP Wrocław), FIATA MT BL and PUESC clearance flow. Scoped to Trina Solar Vertex S+ family modules paired with Sungrow SG125HT or Huawei SUN2000-330KTL-H1 BoS. Drops unsupported "≤ 5 % string spread" internal control and 48h reply SLA; instruments table marked PENDING pending instrument-record lookup. RFQ CTA re-pointed to /rfq/ site path; no mailto labelled as download; placeholder /downloads/ paths removed.