Process / SOP EVSE Maintenance · Equipment: TradVolt TV-VP-22 kW-AC7 / Sungrow SG125HT DC-side wiring · Corridor: CN → SK · Evidence-date: 2026-09-22

Solar DC-Cable Megger Test — Corridor CN→SK (Vertical EVSE)

Verdict (this SOP): 9 numbered steps; pass threshold = insulation resistance ≥ 1 MΩ on each of the three pairs (string +/−, +/E, −/E) read after a stable 60-second hold, taken at the per-cable DC test voltage stated by the OEM datasheet (500 V DC for ELV PV string circuits; 1 000 V DC for strings with a maximum system voltage up to 1 500 V DC, per IEC 62548-1:2023, §7). Indicative on-site duration ≈ 4 h per EVSE, two qualified technicians (one operator, one witness). All cost slots are indicative; HS code and duty rate are PENDING — lookup against live TARIC at moment of import. Standards cited below are referenced by designation + edition; full text is not held in copy and must be sourced by the reader.

Item	Value	Source / scope
Equipment family	TradVolt TV-VP vertical EVSE pedestal (22 kW AC7); DC-side PV string cabling per Sungrow SG125HT string-inverter product page (exact datasheet rev. 2025-09 confirmed at RFQ — MODEL ASSUMPTION)	OEM manuals cited §12
Test location	CN supplier ex-works receiving (T4) + SK commissioning site (T5)	This SOP, §6
Horizon	Single commissioning event + re-qualification after transit / storage	This SOP, §1
Pass threshold	≥ 1 MΩ per pair, held 60 s, at the cable-rated DC test voltage	IEC 62548-1:2023 §7 (referenced); IEC 60364-6:2016 §61 (referenced)
Test voltage	500 V DC ELV; 1 000 V DC up to 1 500 V DC string	Sungrow SG125HT product page; IEC 62548-1:2023 §7
Step count	9 (HowTo schema) / 10 in expanded step table §4	This SOP, §4
Indicative duration	≈ 4 h per EVSE	This SOP, §6 T5
Evidence-date	2026-09-22	Page header
Limitation	Standards not held in copy; HS code PENDING — lookup; SK duty rate PENDING — lookup; costs indicative only; Sungrow SG125HT datasheet rev. 2025-09 is a MODEL ASSUMPTION pending RFQ confirmation	§8; §11

Request Quote — replies in 48h

1. Scope and Applicability

This SOP covers insulation-resistance (megger) testing of the DC string cabling between the photovoltaic input and the DC bus of the TradVolt TV-VP vertical EVSE pedestal, with the DC-side architecture defined by the Sungrow SG125HT utility-grade 3-phase string inverter (1 500 V DC max input), per the Sungrow string-inverter range page. It applies to units sourced from CN suppliers and commissioned on sites in SK, and may be reused for re-qualification after transit, storage, or on-site events. Test voltages (500 V DC, 1 000 V DC) are read off the cable datasheet and cross-checked against the SG125HT installation manual revision (rev. 2025-09 — MODEL ASSUMPTION confirmed at RFQ) cited in §12.

2. Reference Framework

Standards are referenced by designation, edition, and issuing body. TradVolt does not hold full-text standards in copy; readers must source the documents themselves via the catalogue pages listed below.

IEC 60364-6:2016 — Low-voltage electrical installations — Part 6: Verification (issuer: International Electrotechnical Commission) — referenced for the insulation-resistance test method. Catalogue entry: IEC 62446-1:2016 — PV systems, requirements for testing, documentation and maintenance, Part 1: Grid connected systems (TC 82) (companion document on PV-side commissioning verification; the IEC 60364-6:2016 home entry must be obtained from the IEC Webstore catalogue search and is not held in copy).
IEC 62548-1:2023 — Photovoltaic (PV) arrays — Part 1: Design requirements (issuer: International Electrotechnical Commission, TC 82) — referenced for array-side test voltages and insulation-resistance practice. Exact document page: IEC 62548-1:2023 — PV arrays, Part 1: Design requirements (TC 82).
IEC 61215-1:2021 / IEC 61215-1-1:2021 — Terrestrial photovoltaic (PV) modules — Design qualification and type approval — Part 1: Test requirements / Part 1-1: c-Si special requirements (issuer: International Electrotechnical Commission, TC 82). Document pages: IEC 61215-1:2021 · IEC 61215-1-1:2021.
IEC 61730-1:2016 (ed. 2) / IEC 61730-1:2023 (ed. 3) — Photovoltaic (PV) module safety qualification — Part 1: Requirements for construction (issuer: International Electrotechnical Commission, TC 82). Document pages: IEC 61730-1:2016 ed. 2 · IEC 61730-1:2023 ed. 3.
UL 61730-1 — Photovoltaic (PV) Module Safety Qualification — Part 1 (issuer: UL LLC). Document page: UL 61730-1.
ISO 2859-1:1999 — Sampling procedures for inspection by attributes — Part 1: Sampling plans indexed by acceptable quality level (AQL) for lot-by-lot inspection (issuer: International Organization for Standardization). Catalogue lookup: ISO search for 2859 (exact /standard/NNNNN.html deep URL not held — cite ISO number + title + year in text and source from ISO catalogue).
ICC Incoterms 2020 (DAU publication 723E; issuer: International Chamber of Commerce). Rules page: Incoterms 2020.
EU TARIC consultation (issuer: European Commission, DG TAXUD). Lookup tool: TARIC consultation.

3. Prerequisites

Approved method statement and risk assessment for the SK site.
Calibrated insulation resistance tester with valid calibration label.
Lock-out / tag-out kit applied at the DC isolator and PV array combiner.
Two qualified personnel: one to operate, one to witness and record.
Ambient temperature and humidity logged; surface dry.

4. Step Sequence

Step #	Action	Owner	Input doc	Output doc	Done-when
1	Confirm scope, EVSE serial, and corridor reference (CN supplier, SK site).	Project Engineer	PO / packing list	Job card	Serial, site, and date recorded on the job card.
2	Issue insulated gloves, arc-rated face shield, and voltage-rated tools.	Site Supervisor	PPE register	PPE sign-off sheet	PPE sign-off sheet countersigned by both technicians.
3	Open the DC isolator at the EVSE and at the PV combiner; apply LOTO.	Electrician	Single-line diagram	LOTO log entry	LOTO tag affixed and verified by second person.
4	Verify zero DC voltage between string + / − / earth using an approved two-pole tester.	Electrician	Live-work permit	Pre-test voltage check	0 V DC indicated on all three pairs; reading photographed.
5	Identify and label string positive, negative, and protective earth conductors.	Electrician	Wiring diagram	Label map	All conductors labelled and matched to the wiring diagram.
6	Perform the insulation resistance test at the rated DC test voltage per the cable datasheet; minimum 500 V DC for ELV PV string circuits, typically 1 000 V DC for strings up to 1 500 V DC.	Electrician	Cable datasheet; Sungrow SG125HT installation manual (rev. 2025-09 — MODEL ASSUMPTION, confirmed at RFQ)	Test record sheet	Stable reading held for 60 s on each pair (+/−, +/E, −/E).
7	Record measured insulation resistance in MΩ per pair, with ambient temperature and humidity.	Test Witness	Test record sheet	Completed test record	All three pairs logged with values, units, and ambient conditions.
8	Pass / fail decision against the acceptance value stated in the project specification; investigate and re-terminate any reading below the threshold.	Commissioning Engineer	Test record sheet, spec	Decision note	Decision recorded as PASS, RE-TEST, or FAIL with signature.
9	Remove LOTO, close DC isolators, and verify normal standby state of the EVSE.	Electrician	LOTO log	Restoration note	Standby state observed and confirmed on the EVSE HMI.
10	Archive the signed test record with the EVSE file and issue the commissioning sign-off.	QA / Document Controller	Test record sheet	Commissioning dossier	Record indexed in the project folder with retention reference.

5. Acceptance Criteria

Indicative threshold: insulation resistance ≥ 1 MΩ per pair at the applied DC test voltage, per typical PV string practice referenced in IEC 62548-1:2023. Project-specific values issued by the design engineer shall override this indicative figure. Cost slots below are indicative only.

6. Timeline with Dependencies

Phase	Activity	Indicative duration	Depends on
T0	Goods ex-works CN supplier (Incoterms 2020)	1–3 days	—
T1	CN export customs clearance	2–5 days	T0
T2	Main carriage CN → SK (rail / road)	14–22 days	T1
T3	SK import customs clearance (TARIC / CDS)	2–4 days	T2
T4	In-house receiving inspection and megger test	0.5 day per unit	T3, calibration of tester valid
T5	Site delivery and on-site megger test (this SOP)	~4 h per EVSE	T4, site access
T6	Commissioning dossier sign-off	1 day	T5

7. Indicative Cost Slots

Cost slot	Status	Notes
Pre-shipment inspection (CN)	indicative	Quoted per man-day; subject to supplier location.
Main carriage CN → SK	UNCERTAIN	Rate depends on mode (rail / road), Incoterms 2020 choice, and fuel surcharge.
SK import duties & VAT	PENDING — lookup	See Section 8 — Duty / HS block.
On-site megger test labour	indicative	~4 h per EVSE with two qualified technicians.
Re-termination / rework (if triggered)	UNCERTAIN	Material dependent; charged on time-and-materials basis.

8. Duty / HS Block

HS classification — lookup required. The Harmonised System code for the equipment and the spare parts handled under this SOP must be confirmed against the official EU TARIC consultation query (TARIC consultation) and the SK national customs tariff at the moment of import. Indicative candidates are 8544.42 (electric conductors, fitted with connectors) for the PV DC cable assemblies and 8537 (boards/panels for electric control) for the EVSE control assembly; these are placeholders, not computed classifications.

Duty rate: PENDING — lookup. Rates depend on the declared HS code, the origin declared on the commercial invoice, and any preferential treatment applicable under EU free-trade arrangements. The free-of-charge TARIC consultation query above is the computed lookup; no figure is asserted here.

Disclaimer: TradVolt does not provide customs, tax, or legal advice. Figures and classifications must be validated by a licensed customs broker against the live TARIC at the time of entry.

9. Document Checklist (literal filenames)

JOB-CARD-EVSE-{SERIAL}.pdf — site and unit identification.
LOTO-LOG-{SITE}-{DATE}.xlsx — lock-out / tag-out record.
PRE-TEST-VOLTAGE-{SERIAL}.jpg — photographic evidence of zero-voltage check.
MEGGER-RECORD-{SERIAL}.pdf — measured values, units, ambient conditions.
DECISION-NOTE-{SERIAL}.pdf — PASS / RE-TEST / FAIL decision.
COMMISSIONING-DOSSIER-{SITE}.zip — final archived package.

10. Reader-Facing CTAs

Request Quote — replies in 48h

11. Claim-Row Provenance

Sources cited on this page

[Claim: Megger test voltage minimum 500 V DC for ELV PV string circuits and 1 000 V DC for strings up to 1 500 V DC. | Src: IEC 62548-1:2023 — Photovoltaic (PV) arrays — Part 1: Design requirements (issuer: IEC, TC 82). | URL: https://webstore.iec.ch/en/publication/64171 (exact document page) | Standards not held in copy; reader must source. | accessed 2026-09-22]
[Claim: Insulation resistance acceptance value of ≥ 1 MΩ is the typical PV string practice referenced in IEC 62548-1:2023. | Src: IEC 62548-1:2023 (issuer: IEC, TC 82). | URL: https://webstore.iec.ch/en/publication/64171 | Standards not held in copy; reader must source. | accessed 2026-09-22 — MODEL ASSUMPTION: treated as indicative; project specification overrides.]
[Claim: Verification procedure for low-voltage electrical installations, including insulation resistance, is defined in IEC 60364-6:2016. | Src: IEC 60364-6:2016 (issuer: IEC). | URL: https://webstore.iec.ch/ (catalogue query, search "60364-6"; exact /publication/NNNN ID not held — never invent) | Standards not held in copy; reader must source. | accessed 2026-09-22]
[Claim: PV module safety qualification is addressed by UL 61730-1. | Src: UL 61730-1 (issuer: UL LLC). | URL: https://www.shopulstandards.com/ProductDetail.aspx?productId=UL61730-1 | accessed 2026-09-22]
[Claim: PV module safety qualification — construction requirements — is addressed by IEC 61730-1:2016 ed. 2 / IEC 61730-1:2023 ed. 3. | Src: IEC 61730-1:2016 / IEC 61730-1:2023 (issuer: IEC, TC 82). | URLs: https://webstore.iec.ch/en/publication/25674 (2016 ed. 2) · https://webstore.iec.ch/en/publication/59803 (2023 ed. 3) | accessed 2026-09-22]
[Claim: PV module design qualification is addressed by IEC 61215-1:2021 (Part 1 test requirements) and IEC 61215-1-1:2021 (Part 1-1 c-Si special requirements). | Src: IEC 61215-1:2021 / IEC 61215-1-1:2021 (issuer: IEC, TC 82). | URLs: https://webstore.iec.ch/en/publication/61345 · https://webstore.iec.ch/en/publication/61346 | accessed 2026-09-22]
[Claim: Attribute inspection sampling uses the AQL framework of ISO 2859-1:1999. | Src: ISO 2859-1:1999 — Sampling procedures for inspection by attributes — Part 1 (issuer: ISO). | URL: https://www.iso.org/search.html?q=2859 (catalogue search; exact /standard/NNNNN.html deep URL not held — cite ISO number+title+year in text) | Standards not held in copy; reader must source. | accessed 2026-09-22]
[Claim: Cross-border procurement and commissioning terms (DAP / CIP) are defined in ICC Incoterms 2020. | Src: ICC Incoterms 2020 (DAU publication 723E; issuer: International Chamber of Commerce). | URL: https://iccwbo.org/business-solutions/incoterms-rules/incoterms-2020/ | accessed 2026-09-22]
[Claim: EU import classification and duty rates are consulted via the TARIC database maintained by the European Commission. | Src: TARIC consultation (issuer: European Commission, DG TAXUD). | URL: https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Lang=en | accessed 2026-09-22]
[Claim: TradVolt vertical EVSE pedestal family referenced as TV-VP. | Src: TradVolt internal SKU catalogue (vertical pedestal family). | URL: /suppliers/ (TradVolt supplier catalogue; exact OEM cross-reference confirmed at RFQ) | accessed 2026-09-22 — MODEL ASSUMPTION: SKU nomenclature is internal; cross-reference to specific OEM SKUs validated during quotation.]
[Claim: DC-side architecture of the TV-VP pedestal aligns with the Sungrow SG125HT utility-grade 3-phase string inverter (1 500 V DC max input), per the Sungrow string-inverter range page. | Src: Sungrow product page (issuer: Sungrow Power Supply Co., Ltd.). | URL: https://www.sungrowpower.com/en/products/string-inverter | accessed 2026-09-22 — MODEL ASSUMPTION: exact OEM datasheet revision (rev. 2025-09) and per-cable test voltage confirmed at RFQ.]
[Claim: UL 9540A test method is referenced for the storage-coupled TV-VP variants (out of scope for this DC-cable SOP; cited for completeness). | Src: UL 9540/9540A/1973 certification scope page (issuer: UL LLC). | URL: https://www.ul.com/services/energy-storage-system-testing-and-certification | accessed 2026-09-22]

All duty rates on this page are marked PENDING — lookup; classifications and percentages must be re-validated against the live TARIC and SK national tariff at the moment of import. Standards cited above are not held in copy; readers must source the documents via the catalogue pages listed. The Sungrow SG125HT datasheet revision (rev. 2025-09) and the per-cable DC test voltage are treated as MODEL ASSUMPTIONs until the OEM datasheet is re-confirmed at RFQ.