Process SOP Vertical: Solar BoS Corridor: CN → RS
EVSE Cable Flex Endurance Test — Corridor CN→RS
Standard Operating Procedure for incoming cable flex endurance verification on EV charging units routed through a China-to-Serbia solar Balance-of-System (BoS) trade lane.
1. Purpose and Scope
This SOP defines the in-house cable flex endurance test applied to EV supply equipment (EVSE) subassemblies received from Chinese OEM partners and staged for solar BoS integration projects in the Republic of Serbia. The procedure covers acceptance testing of the cable assembly only; it does not replace the OEM's full type-test regime.
[Claim: SOP scope is limited to cable flex endurance verification on inbound EVSE shipments. | Src: Internal Tradvolt Process Library | URL: https://tradvolt.com/process/ | accessed 2026-09-21]
2. Normative References
- IEC 62196-1 — Plugs, socket-outlets, vehicle connectors and vehicle inlets — Conductive charging of electric vehicles — Part 1: General requirements.
- IEC 60245-1 — Rubber insulated cables — Rated voltages up to and including 450/750 V.
- UL 2251 — Standard for Plugs, Receptacles and Couplers for Electric Vehicles.
- ISO 2859-1 — Sampling procedures for inspection by attributes — Single sampling plans by AQL.
- IEC 61982 — Secondary batteries (insofar as referenced for harness testing).
- CE marking framework — EU Regulation (EC) No 765/2008.
[Claim: IEC 62196-1 defines mechanical and electrical requirements for EV charging couplers. | Src: IEC 62196-1 (International Electrotechnical Commission) | URL: https://webstore.iec.ch/en/publication/6582 | accessed 2026-09-21]
[Claim: ISO 2859-1 governs attribute-based AQL sampling for lot inspection. | Src: ISO 2859-1 (International Organization for Standardization) | URL: https://www.iso.org/standard/114327.html | accessed 2026-09-21]
3. Step Sequence
| Step # | Action | Owner | Input doc | Output doc | Done-when |
|---|---|---|---|---|---|
| 1 | Receive shipment and reconcile CN→RS transport documents. | Logistics Coordinator | Commercial invoice, packing list, CN→RS transit manifest | Goods receipt note (GRN) | Quantity and part numbers reconciled; discrepancy log opened if any mismatch. |
| 2 | Sample units per the AQL plan defined in Section 5. | QA Inspector | Goods receipt note, AQL sampling table | Sampling worksheet | Sample units identified, tagged, and recorded with serial numbers. |
| 3 | Condition samples for 24 hours at 23 °C ± 2 °C. | QA Inspector | Sampling worksheet, climate log | Conditioning log entry | Chamber log shows 24 hours continuous dwell at the target temperature. |
| 4 | Perform pre-test visual and dimensional inspection. | QA Inspector | OEM datasheet / service manual | Pre-test inspection sheet | Connector pins, jacket, and strain relief pass visual criteria; dimensions recorded. |
| 5 | Execute cable flex endurance cycle on a calibrated rig. | Test Engineer | Test rig calibration certificate, flex cycle procedure | Flex cycle raw data file | Required cycle count completed; ambient and load values logged throughout. |
| 6 | Conduct post-cycle electrical verification. | Test Engineer | Test method reference (per OEM manual) | Post-cycle electrical report | Continuity, insulation resistance, and hi-pot results recorded against limits. |
| 7 | Compile the batch test report. | QA Inspector | Pre-test sheet, flex data file, post-cycle report | Batch test report (signed) | Report contains raw data, pass/fail flags, and operator signatures. |
| 8 | Apply acceptance decision per OEM criteria. | QA Manager | Batch test report, OEM acceptance criteria | Acceptance decision record | Lot released, conditionally released, or quarantined; justification logged. |
| 9 | Release accepted units into the solar BoS kit staging area. | Warehouse Supervisor | Acceptance decision record | Staging transfer note | Units moved to RS-dispatch zone; traceability tag updated. |
4. Test Method
The flex endurance cycle is executed on a motorised flex rig with a bend radius set per the cable manufacturer datasheet. Each sample is routed through the rig mandrels, weighted to the rated hanging mass per the OEM service manual, and cycled at the documented stroke rate. Cycle count, ambient temperature (°C), and applied mass (kg) are logged continuously.
[Claim: IEC 62196-1 specifies mechanical tests for charging couplers including flex endurance. | Src: IEC 62196-1 (International Electrotechnical Commission) | URL: https://webstore.iec.ch/en/publication/6582 | accessed 2026-09-21]
[Claim: UL 2251 covers construction and performance of EV plugs, receptacles, and couplers. | Src: UL 2251 (Underwriters Laboratories) | URL: https://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=35173 | accessed 2026-09-21]
5. AQL Sampling Plan
Lot inspection is performed in accordance with ISO 2859-1, normal inspection level II, with an Acceptable Quality Limit (AQL) of 1.0 for major defects and 2.5 for minor defects, unless otherwise required by the OEM service manual.
[Claim: ISO 2859-1 normal inspection level II is the default attribute sampling plan. | Src: ISO 2859-1 (International Organization for Standardization) | URL: https://www.iso.org/standard/114327.html | accessed 2026-09-21]
6. Document Checklist
Operators must confirm the following files are present in the batch folder before starting the procedure:
GRN_[lot_number]_[date].pdfSamplingWorksheet_[lot_number].xlsxConditioningLog_[lot_number].csvPreTestInspection_[lot_number].pdfFlexCycle_RawData_[lot_number].csvPostCycleElectrical_[lot_number].pdfBatchTestReport_[lot_number]_signed.pdfAcceptanceDecision_[lot_number].pdfTestRigCalibrationCert_[serial].pdf— valid within 12 months.OEM_Datasheet_[model].pdf
7. Timeline and Dependencies
| Phase | Duration | Dependency | Owner |
|---|---|---|---|
| Goods receipt and GRN | 0.5 working day | CN→RS shipment physically arrived; transport documents released. | Logistics Coordinator |
| AQL sampling | 0.5 working day | GRN finalised. | QA Inspector |
| Climate conditioning (23 °C ± 2 °C) | 24 hours | Sampling complete; chamber free. | QA Inspector |
| Pre-test inspection | 2 hours per sample set | Conditioning finished. | QA Inspector |
| Flex endurance cycle | up to 7 working days | Rig available and calibration certificate valid. | Test Engineer |
| Post-cycle electrical tests | 1 working day | Flex cycle completed without mechanical break. | Test Engineer |
| Reporting and acceptance decision | 1 working day | All raw data files signed and archived. | QA Manager |
| Release to RS staging | 0.5 working day | Acceptance decision signed. | Warehouse Supervisor |
8. Duty / HS Classification Block
| Item | Harmonized System (HS) code | Duty rate (Serbia) | Source |
|---|---|---|---|
| EV charging cable assembly, with connectors (EVSE accessory) | 8544.42 | PENDING — lookup | Serbian Customs Administration — official tariff portal |
| EV charging station complete unit (for reference) | 8504.40 | PENDING — lookup | Serbian Customs Administration — official tariff portal |
[Claim: HS heading 8544 covers insulated wire, cable, and electric conductors. | Src: WCO Harmonized Commodity Description and Coding System (World Customs Organization) | URL: https://www.wcoomd.org/en/topics/nomenclature/instrument-and-tools.aspx | accessed 2026-09-21]
[Claim: HS heading 8504 covers static converters, including rectifiers and power supplies. | Src: WCO Harmonized Commodity Description and Coding System (World Customs Organization) | URL: https://www.wcoomd.org/en/topics/nomenclature/instrument-and-tools.aspx | accessed 2026-09-21]
9. Cost Slots
| Cost slot | Value | Status |
|---|---|---|
| Rig calibration fee per batch | indicative | Internal allocation; confirm with QA finance. |
| Operator labour per batch | UNCERTAIN | Driven by shift pattern. |
| Serbian import duty on 8544.42 | PENDING — lookup | Confirm on Serbian Customs portal. |
| Serbian import VAT (reference) | PENDING — lookup | Confirm on Serbian Tax Administration portal. |
| Cross-border transport surcharge (CN→RS) | indicative | Based on lane average; varies by INCOTERMS basis. |
[Claim: Incoterms 2020 define seller/buyer obligations for cross-border trade including transport and risk transfer. | Src: ICC Incoterms 2020 (International Chamber of Commerce) | URL: https://iccwbo.org/business-solutions/incoterms-rules/incoterms-2020/ | accessed 2026-09-21]
[Claim: FIATA documents are recognised multimodal transport documents used in international forwarding. | Src: FIATA (International Federation of Freight Forwarders Associations) | URL: https://fiata.org/ | accessed 2026-09-21]
10. Acceptance Criteria
A sample passes the cable flex endurance test when, after the prescribed cycle count:
- No conductor break is detected in the post-cycle continuity test.
- Insulation resistance and hi-pot readings meet the limits stated in the OEM service manual.
- No jacket cracking, exposed conductor, or connector pin damage is observed.
Lot acceptance follows ISO 2859-1 AQL sampling. A failed lot is quarantined, a Non-Conformance Report (NCR) is opened, and the OEM is notified in writing.
11. Records and Retention
All batch test records are retained for a minimum of 7 years in the QA archive. Calibration certificates for the flex rig and electrical test instruments are retained for their full validity period plus 3 years.
12. Reader-Facing RFQ and Download
Direct RFQ path: https://tradvolt.com/rfq?topic=evse-cable-flex-test-cn-rs — Direct download path: https://tradvolt.com/downloads/evse-cable-flex-test-cn-rs-checklist.pdf