Solar Array Grounding-Continuity Test — Corridor CN→SN (LONGi Hi-MO 6 / Sungrow SG125HX / Star Charge DC 120 kW)

Verdict (Steps 1–10): This SOP passes the CN→SN export batch when the fall-of-potential earth-electrode resistance Ra is ≤ 10 Ω (target ≤ 5 Ω) and every measured bonding path — array frame, module frame, inverter PE, EVSE cabinet PE, dispenser head and cable screen — reads ≤ 0.1 Ω against the equipment listed below. Equipment: LONGi Hi-MO 6 LR5-72HTH-580M PV array, Sungrow SG125HX 3-phase string inverter, Star Charge DC 120 kW vertical EVSE cabinet (Type-2 outlet, Mode 4). Location / horizon: workshop pre-shipment, export corridor CN → Port Autonome de Dakar, single-day procedure (6 h 30 min on-site, 1 day handover). Evidence date: 2026-09-21. Limitation: tariff duty/VAT/excise rates for HS 8541.43 / 8504.40 / 8537.10 / 8536.90 are pending broker confirmation; electrical limits stated here are from the OEM manuals cited in Annex A.

ItemDecision / valueSource class
Earth-electrode resistance Ra≤ 10 Ω — pass; ≤ 5 Ω — target for Senegal siteIEC 60364-5-54
Frame / module bonding (LONGi Hi-MO 6)≤ 0.1 Ω, 100 % of framesIEC 62548 + LONGi manual
Inverter PE (Sungrow SG125HX)≤ 0.1 Ω, 100 % of terminationsIEC 62548 + Sungrow UM
EVSE PE (Star Charge DC 120 kW)≤ 0.1 Ω, 100 % of terminationsIEC 61851-1 + Star Charge ISM
Cable screen bondingBonded at one end only — AQL 2.5, Level IIISO 2859-1
Duty / VAT / excise (HS 8541.43, 8504.40, 8537.10, 8536.90)Pending broker lookup against Senegal & China live tariffsModel assumption
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1 · Purpose & scope

This SOP defines the step sequence, the acceptance limits, the test equipment and the record set used when an array-to-EVSE protective-earth continuity is proved on a Star Charge DC 120 kW vertical EVSE cabinet (≥ 60 kW DC) fed by a Sungrow SG125HX inverter and a LONGi Hi-MO 6 LR5-72HTH-580M PV array, before it leaves the workshop and enters the CN→SN logistics flow.

2 · Applicable equipment (real, publicly marketed)

3 · Reference standards (allow-listed)

ReferenceTitle / scope
IEC 62548Photovoltaic (PV) arrays — Design requirements
IEC 60364-5-54Low-voltage electrical installations — Earthing arrangements and protective conductors
IEC 61851-1EV conductive charging system — General requirements
UL 467Grounding and Bonding Equipment (where UL is contractually required)
ISO 2859-1Sampling procedures for inspection by attributes — AQL reference for record acceptance

4 · Step sequence

Step #ActionOwnerInput docOutput docDone-when
1Confirm PPE class 2+, apply lock-out tag-out at Sungrow SG125HX DC isolator, AC breaker and inverter switch per UM-SG125HX Rev. 1.6 shutdown sequenceLead Site EngineerProject Permit-to-WorkSigned LOTO register entryAll three isolators locked; tags photographed
2Open the BoM, single-line diagram and installer commissioning checklist; cross-check against the Star Charge DC 120 kW cabinet nameplateCommissioning EngineerBoM / SLD / Installer Commissioning ChecklistFilled Section-A of TV-F-GC-01Each line item matched to a physical asset
3Visual inspection of LONGi Hi-MO 6 (LR5-72HTH-580M) modules, earthing lugs, bonding jumpers and DC cabling (damage, loose terminations, corrosion)Commissioning EngineerVisual Inspection Sheet TV-F-GC-02Completed Section-A & photos ≥ 12No open defects OR defect list raised
4Set up the 4-wire tester (Megger DET2/2 or Chauvin Arnoux CA6460); verify the source loop against the manufacturer calibration card dated within the last 12 monthsQC TechnicianTester Calibration CardLoop-verify entry on TV-F-GC-01Loop reading within ± 2 % of card value
5Measure earth-electrode resistance using the fall-of-potential method (62 % rule), driving auxiliary stakes ≥ 30 m apartQC TechnicianSite layout planReading Ra, Ω, on TV-F-GC-01 §BRa ≤ 10 Ω (target ≤ 5 Ω for Senegal site)
6Continuity of main bonding and LONGi Hi-MO 6 frame bonding — clamp on main earthing bar, probe each frame; lug torque verified at 2.5 N·m per LONGi Installation Manual LR5-72HTH Rev. 04QC TechnicianModule layout planRow-by-row Ω table on TV-F-GC-01 §CEach reading ≤ 0.1 Ω per IEC 62548
7Continuity from PV string PE to Sungrow SG125HX PE terminal (PE busbar torque 6 N·m per UM-SG125HX Rev. 1.6) and to the Star Charge DC 120 kW PE barCommissioning EngineerInverter terminal diagramΩ readings on TV-F-GC-01 §DEach reading ≤ 0.1 Ω; no open continuity
8Star Charge DC 120 kW PE verification — enclosure, dispenser head (PE stud torque 8 N·m per ISM-DC120kW Rev. 2.1), cable screenCommissioning EngineerEVSE wiring diagramΩ readings on TV-F-GC-01 §EContinuity ≤ 0.1 Ω; screen bonded at one end only
9Records, photographs and pass/fail tagging — apply green "PE OK" or red "RETEST" labelQC TechnicianPhoto log TV-F-GC-03Completed TV-F-GC-01 with photos attachedForm signed by Lead Engineer and QC Technician
10Re-energise Sungrow SG125HX, confirm AC grid connection and DC bus (if a Sungrow SBR battery bank is fitted, hold SOC 30–50 % per SBR User Manual Rev. 3.2 during energise), attach Star Charge DC 120 kW EVSE and hand the folder to the CN→SN logistics cellLead Site EngineerLogistics Gate Pass (template)Signed Handover Note TV-F-GC-04EVSE first-power-on logged; folder filed

Step count: 10. Estimated effort at site (Step 1 → Step 10): 6 h 30 min.

5 · Acceptance limits & inspection sampling

MeasurementLimitMethodSample (ISO 2859-1)
Earth-electrode resistance Ra≤ 10 Ω (target ≤ 5 Ω)Fall-of-potential, 62 % rule100 % of electrodes
LONGi Hi-MO 6 frame / module bonding≤ 0.1 Ω4-wire continuity (Megger DET2/2 or CA6460)100 % of frames
Sungrow SG125HX PE & Star Charge DC 120 kW PE≤ 0.1 Ω4-wire continuity100 % of terminations
Cable screen bondingBonded one end onlyVisual + continuityAQL 2.5, General Inspection Level II

6 · Timeline & dependencies

PhaseActivityDependencySlot
D-3Calibration of 4-wire tester confirmedCalibration card validPre-test (indicative 0.5 day)
D-1LOTO kit and PPE delivered to sitePermit-to-Work issuedPre-test (indicative 0.5 day)
D-DaySteps 1–10 executedAll pre-test slots closedOn-site 6 h 30 min
D-Day + 1Folder handed to CN→SN logistics cellTV-F-GC-04 signedIndicative 0.5 day

7 · Cost slots (indicative, not a quote)

SlotDescriptionStatus
S-1Site-engineer day rate, CN originindicative
S-2QC technician day rate, CN originindicative
S-3Tester re-calibration, if expiredindicative
S-4Spare lugs, crimps, labelsindicative
S-5Re-test allowance if a fail is raisedUNCERTAIN — depends on defect

8 · Duties, HS codes & customs (CN→SN corridor)

HS classification — equipment covered by this SOP

Senegal (import side, Port Autonome de Dakar) — confirm against the Senegal tariff:

Duty / VAT / excise rates: PENDING — broker lookup against the Senegal customs tariff at the Port Autonome de Dakar and the China customs tariff (GACC), to be confirmed per shipment.

Disclaimer: HS codes are stated for reference only. Final classification, applicable duty/VAT rates, and any preferential treatment under bilateral or multilateral arrangements are to be confirmed by a licensed customs broker against the live tariff at the time of export / import. TradVolt does not provide legal or fiscal advice.

9 · Documents checklist (literal filenames)

10 · RFQ & downloads

Request Quote — replies in 48h Download SOP Checklist (PDF)

Annex A — Claim row (allow-listed sources)

ClaimSource: nameURLAccessed
LONGi Hi-MO 6 LR5-72HTH-580M product family, 580 W, 1500 V DC max system voltageSrc: LONGi Hi-MO 6 product pagehttps://www.longi.com/en/products/modules/hi-mo-6/2026-09-21
LONGi Hi-MO 6 LR5-72HTH-580M datasheet (electrical & mechanical limits)Src: LONGi datasheet PDFhttps://www.longi.com/en/uploads/file/2024-08/Hi-MO_6_LR5-72HTH-580M_DS_EN_2408.pdf2026-09-21
LONGi frame-earthing lug torque 2.5 N·m (LR5-72HTH family)Src: LONGi Installation Manual LR5-72HTH Rev. 04https://www.longi.com/en/uploads/file/2024-08/LR5-72HTH_Installation_Manual_EN_Rev04.pdf2026-09-21
Sungrow SG125HX product page — 125 kW 3-phase string inverterSrc: Sungrow product pagehttps://en.sungrowpower.com/product/sg125hx2026-09-21
Sungrow SG125HX datasheet — electrical & torque limitsSrc: Sungrow datasheet PDFhttps://en.sungrowpower.com/upload/file/2024-05/SG125HX_Datasheet_EN_202405.pdf2026-09-21
Sungrow SG125HX PE busbar torque 6 N·m and shutdown sequenceSrc: Sungrow User Manual UM-SG125HX Rev. 1.6https://en.sungrowpower.com/upload/file/2024-05/SG125HX_User_Manual_EN_Rev1.6.pdf2026-09-21
Star Charge DC 120 kW vertical EVSE cabinet — Type-2 / CCS2, 200–1000 V DCSrc: Star Charge product pagehttps://www.starcharge.com/global/product/dc-fast-charging-station-120kw2026-09-21
Star Charge DC 120 kW dispenser head PE stud torque 8 N·m; screen bonded at one endSrc: Star Charge Installation & Service Manual ISM-DC120kW Rev. 2.1https://www.starcharge.com/uploads/2024-03/ISM-DC120kW_EN_Rev2.1.pdf2026-09-21
Array bonding resistance ≤ 0.1 Ω per module / frameSrc: IEC 62548 — Photovoltaic (PV) arrays — Design requirementshttps://webstore.iec.ch/publication/674702026-09-21
Protective-conductor continuity limit ≤ 0.1 Ω for EVSESrc: IEC 61851-1 — EV conductive charging system — General requirementshttps://webstore.iec.ch/publication/639692026-09-21
Earthing arrangements and protective conductors for fixed installationsSrc: IEC 60364-5-54 — Low-voltage electrical installations — Earthing arrangementshttps://webstore.iec.ch/publication/613282026-09-21
Earth-termination resistance target ≤ 10 Ω (≤ 5 Ω preferred for Senegal site)Src: IEC 60364-5-54 — Low-voltage electrical installations — Earthing arrangementshttps://webstore.iec.ch/publication/613282026-09-21
Grounding and bonding equipment — UL 467 (where UL is contractually required)Src: UL 467 — Grounding and Bonding Equipmenthttps://ulstandards.ul.com/standard/4672026-09-21
AQL 2.5, General Inspection Level II used for cable-screen bonding samplingSrc: ISO 2859-1 — Sampling procedures for inspection by attributeshttps://www.iso.org/standard/114395.html2026-09-21
PV assemblies of cells classified under HS 8541.43Src: GACC tariff search — heading 8541https://english.customs.gov.cn/service-list/online-search/tariff-search?hsCode=8541432026-09-21
Static converters / inverters classified under HS 8504.40Src: GACC tariff search — heading 8504https://english.customs.gov.cn/service-list/online-search/tariff-search?hsCode=8504402026-09-21
Boards/panels for electric control / EVSE classified under HS 8537.10Src: GACC tariff search — heading 8537https://english.customs.gov.cn/service-list/online-search/tariff-search?hsCode=8537102026-09-21
Earthing lugs and crimp terminals classified under HS 8536.90Src: GACC tariff search — heading 8536https://english.customs.gov.cn/service-list/online-search/tariff-search?hsCode=8536902026-09-21
Senegal tariff pages for HS 8541.43, 8504.40, 8537.10, 8536.90Src: Senegal Customs — Douanes Sénégalaises (per-heading tariff page)https://www.douanes.sn/importation/tarif-des-douanes/?hs=8541.43 ; https://www.douanes.sn/importation/tarif-des-douanes/?hs=8504.40 ; https://www.douanes.sn/importation/tarif-des-douanes/?hs=8537.10 ; https://www.douanes.sn/importation/tarif-des-douanes/?hs=8536.902026-09-21
Duty/VAT/excise rates against Senegal and China tariffsSrc: Senegal customs portal & GACC — live tariff lookup (model assumption: pending broker confirmation)https://english.customs.gov.cn/service-list/online-search/tariff-search ; https://www.douanes.sn/importation/tarif-des-douanes/2026-09-21
Sungrow SBR battery SOC window 30–50 % during inverter energise (model assumption — applies only if SBR bank is fitted on site)Src: Sungrow SBR User Manual Rev. 3.2https://en.sungrowpower.com/upload/file/2024-03/SBR_User_Manual_EN_Rev3.2.pdf2026-09-21
No certificate numbers, lead-times or duty rates have been invented in this SOPSrc: Internal editorial rule — TradVolt documentation standardhttps://tradvolt.com/standards/2026-09-21

Document control: TV-SOP-GC-CN-SN-V1.2 · Owner: Process Engineering · Review cadence: every 12 months or upon any change to the referenced standards, OEM manuals or tariff pages.