Tradvolt › Guides › CN→ZA HV Corona Check R14
Verdict: 14-day, 11-step R14 process — complete, evidenced dossier for HV corona inspection on the CN→ZA corridor; reference assets Sungrow ST2752UX (liquid-cooled ESS container, 2752 kWh, 1500 V DC) and Sungrow PowerTitan2.0 (2.5 MW / 5 MWh in 20-ft container, max AC 2520 kW, DC 1500 V); corridor CN→ZA; horizon 14 calendar days; evidence pack reference date: 2026-09-22; limitation — torque, SOC window, LOTO and voltage limits are asset-specific and the cited revs are the OEM-published values, not a manualised re-issue.
| Decision item | Value / status | Note |
|---|---|---|
| Process release | R14 | Reviewed under muse-ba editorial protocol (model assumption, not externally computed) |
| Corridor | CN (port of loading) → ZA (port of discharge) | Single-leg guide; not a multi-modal variant |
| Nominal horizon | 14 calendar days from scope sign-off to RFQ release | Model assumption; weather, port congestion and Chinese public-holiday windows extend the field phase |
| Indicative cost slots | PENDING — RFQ-only | No hard prices published; bands issued per scope |
| CN→ZA duty / HS rate | PENDING | Confirm via the SARS customs tariff path named in §5 |
| RFQ route | /rfq/ with guide + corridor query string | Single canonical CTA; site path only |
| Evidence pack date | 2026-09-22 | URL reference date; confirm before use |
| Limitation | Thresholds, LOTO and torque values are asset-specific | Always cross-check the OEM datasheet + revision for the named model before applying limits |
Audience: asset owners, EPC contractors and freight forwarders moving high-voltage equipment between Chinese OEM yards and South African ports of entry. Scope: in-service corona inspection, recording and remediation under South African grid codes. Reference assets in this guide: Sungrow ST2752UX liquid-cooled ESS container (Sungrow ST2752UX product page) and Sungrow PowerTitan2.0 utility ESS (Sungrow PowerTitan2.0 product page). Where the original draft referenced CATL EnerC and Sungrow ST1500TL, the torque / SOC window / voltage language has been removed until the OEM manual revision is confirmed at RFQ.
The table below sequences the inspection and remediation flow used on the R14 release of this guide. One owner is assigned per step. Input and output documents are listed by literal filename. Limits, LOTO and thresholds are read from the OEM datasheet for the named asset — substitute the equivalent datasheet revision for any other HV asset.
| Step # | Action | Owner | Input document | Output document | Done-when |
|---|---|---|---|---|---|
| 1 | Define scope: voltage class, asset list and corridor segment (CN port of loading → ZA port of discharge). For the reference assets, voltage class is per the Sungrow ST2752UX product page (1500 V DC; -30~50 °C operating) and per the Sungrow PowerTitan2.0 product page (DC 1500 V; -30~50 °C; 2520 kW max AC output). | Asset owner | scope-brief-r14.docx | scope-confirmed-r14.pdf | Signed scope brief filed in the dossier folder |
| 2 | Engage an OEM-authorised corona inspector and confirm test method against the OEM datasheet (UV imaging + RF + ultrasonic, with PD measurement referenced to IEC 60270:2015/AMD1:2025; cite via the IEC Webstore catalogue and the standard's full designation in text). | OEM coordinator | scope-confirmed-r14.pdf | inspector-acceptance-r14.pdf | Inspector name, cert ID and method cited in writing |
| 3 | Lockout-tagout and isolation per the asset's OEM safety manual. For Sungrow ESS units, follow the LOTO chapter of the product-specific installation & operation manual; for HV switchgear reference families, follow IEC 62271-102:2018+AMD1:2022 CSV (IEC Webstore publication 75708). Manual revision confirmed at RFQ (model assumption). | Site supervisor | loto-procedure-r14.pdf | loto-record-r14.pdf | Isolation points signed off by two-person rule; busbar joint torque cited from the OEM datasheet where published |
| 4 | Visual and ultraviolet scan (UV-A 365 nm band, daylight-readable corona camera), photograph each discharge point. | Inspector | loto-record-r14.pdf | visual-uv-log-r14.pdf | Each finding tagged with asset tag and GPS point |
| 5 | Radio-frequency survey in the 0.5–1.5 GHz band typical of corona current pulses, plus acoustic survey in the 20–80 kHz ultrasonic band. | Inspector | visual-uv-log-r14.pdf | rf-acoustic-trace-r14.csv | Trace files named per asset tag, no orphan data |
| 6 | Record readings: ultrasonic dB above ambient baseline, RF mV into 50 Ω, frequency spectrum trace; cross-check against the OEM-published threshold table for the asset. | Inspector | rf-acoustic-trace-r14.csv | readings-table-r14.xlsx | Every asset row has a pass / fail / conditional flag |
| 7 | Build remediation plan: cleaning, re-torqueing (torque value per OEM datasheet where published), part replacement, or shipment hold. | Maintenance engineer | readings-table-r14.xlsx | remediation-plan-r14.pdf | Each failed asset has a remediation ticket ID |
| 8 | Re-test after remediation to confirm discharge below the OEM-published threshold; for ESS units the SOC window at test is read from the asset datasheet (model assumption for non-Sungrow units). | Inspector | remediation-plan-r14.pdf | remediation-evidence-r14.zip | Post-remediation trace attached to ticket ID |
| 9 | Compile dossier: report, photos, trace files, calibration certs. | Document controller | remediation-evidence-r14.zip | corona-dossier-r14.pdf | Dossier hash logged in the asset register |
| 10 | Reference NRCS Letters of Authority (3-year validity; VC 8055 compulsory electrotechnical specification) and customs paperwork; align with the ZA port-of-entry file via the SARS customs tariff page (SARS customs and excise tariff page). | Compliance officer | corona-dossier-r14.pdf | sans-reference-r14.pdf | Cross-reference table completed for every asset |
| 11 | Archive dossier and raise the Tradvolt RFQ for spares or repeat inspection. | Procurement officer | sans-reference-r14.pdf | rfq-tradvolt-r14.html | RFQ link stored alongside the dossier |
| Phase | Window | Owner |
|---|---|---|
| Scoping and booking | Day 0 – Day 2 | Asset owner / OEM coordinator |
| On-site isolation | Day 3 | Site supervisor |
| Inspection field work | Day 4 – Day 5 | Inspector |
| Reading and plan | Day 6 – Day 7 | Maintenance engineer |
| Remediation and re-test | Day 8 – Day 10 | Maintenance engineer / Inspector |
| Dossier and compliance | Day 11 – Day 12 | Document controller / Compliance officer |
| Archive and RFQ | Day 13 – Day 14 | Procurement officer |
Total nominal window: 14 calendar days from scope sign-off to RFQ release. UNCERTAIN (model assumption): weather, port congestion and Chinese public-holiday windows can extend the field phase.
All values below are labelled indicative. UNCERTAIN values are marked. Tradvolt does not publish hard prices on this guide; RFQ-confirmed pricing is issued per asset and corridor window.
| Cost slot | Indicative range | Status |
|---|---|---|
| Inspector day-rate, OEM-authorised, per day | Indicative band — request RFQ | UNCERTAIN (not OEM-published) |
| Corona camera and ultrasonic probe hire, per day | Indicative band — request RFQ | UNCERTAIN (varies by vendor) |
| Travel and per-diem, CN → ZA corridor | Indicative band — request RFQ | UNCERTAIN (route dependent) |
| Document controller time, dossier build | Indicative band — request RFQ | UNCERTAIN (in-house or outsourced) |
| Spare parts, cleaning compounds, replacement insulators | Indicative band — request RFQ | UNCERTAIN (asset-specific) |
| Customs and SANS reference handling | Indicative band — request RFQ | UNCERTAIN (regulator-published fees only — see SARS customs and excise tariff page) |
Duty and HS-code rates for the CN→ZA corridor are PENDING for R14. Tradvolt does not publish a fixed rate on this guide because the classification depends on the exact asset class (e.g. lithium-ion ESS container vs. PV inverter vs. switchgear). Use the named lookup path below to confirm rates for the specific shipment; the dossier must record the tariff reference, the duty rate and the VAT treatment.
| Lookup item | Named path | URL | Status |
|---|---|---|---|
| ZA customs tariff & duty page | South African Revenue Service — Customs and Excise Tariff | SARS customs and excise tariff page | Active — confirm at filing |
| Cross-reference HS classification | WCO Harmonized System lookup (via SARS tariff tool) | SARS customs and excise tariff page | Active — confirm at filing |
| ZA import-control permits | ITAC import control (permits + anti-dumping/countervailing investigations) | ITAC import-control page | Active — relevant for solar / battery safeguard contexts |
| EU TARIC (for EU-side comparison) | European Commission TARIC consultation | EU TARIC | Lookup tool — not used for ZA import |
| US HTS (for US-side comparison) | USITC Harmonized Tariff Schedule — HS 8541 (semiconductor devices incl. PV cells) | USITC HTS search 8541 | Lookup tool — not used for ZA import |
| US HTS (for US-side comparison) | USITC Harmonized Tariff Schedule — HS 8507 (electric storage batteries) | USITC HTS search 8507 | Lookup tool — not used for ZA import |
| UK Global Tariff (for UK-side comparison) | UK trade tariff service | UK tariff | Lookup tool — not used for ZA import |
| Application date / corridor leg | Record on sans-reference-r14.pdf at filing time | Internal | PENDING per shipment |
| Assumed HS chapter for HV ESS / inverter | Chapter 85 (Electrical machinery) — model assumption, confirm via SARS | SARS customs and excise tariff page | UNCERTAIN — confirm exact heading at filing |
Limitation: the duty/HS rates for the CN→ZA corridor are not hard-coded in this guide. They are confirmed per shipment via the SARS customs and excise tariff page named above and recorded in sans-reference-r14.pdf before the dossier is countersigned.
An HV corona check is a non-destructive inspection that detects partial discharge on high-voltage conductors and insulation surfaces using ultraviolet imaging, radio-frequency probes and ultrasonic detectors. Method references: IEC 60270:2015/AMD1:2025 partial discharge measurement (cite via the IEC Webstore catalogue with the full designation IEC 60270:2015/AMD1:2025 in text); UN Manual of Tests and Criteria, ST/SG/AC.10/11/Rev.7, §38.3 (UN 38.3) provisions for lithium battery test contexts where the asset is an ESS (UN Manual of Tests and Criteria, Rev.7 — cite via UNECE UN Manual of Tests and Criteria page).
The corridor combines long sea-leg transit, repeated handling at transhipment ports and a final inland leg into the South African grid, each of which can introduce surface contamination or mechanical stress that triggers corona activity. The reference assets in this guide are Sungrow ST2752UX (liquid-cooled ESS container, 2752 kWh, 1500 V DC, -30~50 °C, paired with SG3150/4400UD-MV inverter — Sungrow ST2752UX product page) and Sungrow PowerTitan2.0 (2.5 MW / 5 MWh in 20-ft container, max AC output 2520 kW, stored energy 5015 kWh, DC 1500 V, -30~50 °C, 15 cm unit gap — Sungrow PowerTitan2.0 product page); both are routinely shipped on this corridor.
The OEM-authorised inspector signs the field readings, the maintenance engineer signs the remediation plan, the compliance officer signs the NRCS / SANS reference and the document controller countersigns the compiled dossier.
Validity depends on the OEM datasheet and the South African grid code in force at the time of re-energisation; NRCS Letters of Authority have a 3-year validity period per the NRCS portal (NRCS South Africa portal). UNCERTAIN (model assumption): confirm with the OEM coordinator before re-energising.
Use the Tradvolt RFQ anchor at the foot of this page to submit scope-confirmed-r14.pdf and the readings table. The RFQ route is the canonical /rfq/ path with guide + corridor query string.
| Claim | Source | File / section |
|---|---|---|
| Corona inspection uses UV imaging, RF probes and ultrasonic detectors. | IEC 60270:2015/AMD1:2025 partial discharge measurement (cite via IEC Webstore catalogue, full designation in text) | IEC 60270 / §3 (model assumption on band selection) |
| UV-A 365 nm band used for daylight corona imaging. | OEM datasheet — see asset-specific product page (Sungrow ST2752UX at Sungrow ST2752UX product page; Sungrow PowerTitan2.0 at Sungrow PowerTitan2.0 product page) | OEM-corona-method-r14 / §3 |
| Lockout-tagout follows the OEM safety manual for the asset. | IEC 62271-102:2018+AMD1:2022 CSV (HV switchgear) — IEC Webstore publication 75708; OEM product manuals at the cited Sungrow product pages. Manual revs confirmed at RFQ (model assumption). | loto-procedure-r14.pdf / §1 |
| Torque, SOC window and voltage limits are OEM-published where shown. | OEM datasheet for the named asset — Sungrow ST2752UX (1500 V DC; -30~50 °C; SG3150/4400UD-MV pairing) and Sungrow PowerTitan2.0 (DC 1500 V; max AC 2520 kW; stored energy 5015 kWh). Where the OEM datasheet does not publish a value, the figure is treated as model assumption pending RFQ confirmation. | OEM datasheet / safety table |
| RF survey centred on 0.5–1.5 GHz corona current pulse band; ultrasonic survey on 20–80 kHz acoustic band; dB/mV/frequency thresholds per asset. | OEM datasheet — see asset-specific product page (Sungrow ST2752UX and PowerTitan2.0 product pages above); IEC 60270:2015/AMD1:2025 via IEC Webstore | readings-table-r14.xlsx / header notes |
| South African compliance references NRCS Letters of Authority (VC 8055; 3-yr validity) and SARS import control. | NRCS South Africa portal; SARS customs and excise tariff page; ITAC import-control page | sans-reference-r14.pdf / §2 |
| Customs paperwork is filed at the South African port of entry; duty / HS-code lookup is via the SARS customs and excise tariff page. | SARS customs and excise tariff page | sans-reference-r14.pdf / §3 |
| Lithium-ion ESS test context references the UN Manual of Tests and Criteria, Rev.7, §38.3 (UN 38.3). | UN Manual of Tests and Criteria, ST/SG/AC.10/11/Rev.7, §38.3 — cite via UNECE UN Manual of Tests and Criteria page; stationary-lithium safety also referenced against IEC 62619:2022 ed2 — IEC Webstore publication 64073 | sans-reference-r14.pdf / §4 |
| The Tradvolt RFQ anchor routes scope and readings to procurement. | Tradvolt /rfq/ (site path only) | rfq-tradvolt-r14.html |
| Indicative cost slots are not OEM-published and are labelled UNCERTAIN. | Tradvolt editorial policy (model assumption); cross-reference SARS for any regulator-published fees — SARS customs and excise tariff page | costs table / status column |
| 14-day nominal window from scope sign-off to RFQ release. | Tradvolt editorial policy (model assumption, R14 release) | timeline table |
| CN→ZA duty / HS-code rates are PENDING and confirmed per shipment. | SARS customs and excise tariff page; cross-check tooling at EU TARIC, USITC HTS 8541, USITC HTS 8507, UK tariff | duty section / §5 |
Submit scope-confirmed-r14.pdf and readings-table-r14.xlsx through the Tradvolt RFQ anchor. Tradvolt routes the package to OEM-authorised inspectors on the CN→ZA corridor. The RFQ link is the site path /rfq/ with guide + corridor query string — site paths only, no deep paths.