3 verified items below — verdict: this SOP applies to Sungrow SG125HT string inverters on Egypt (EG) grid code, paired with vertical-rack LFP cabinets; OEM manual revision UM-SG125HT Rev. D; horizon 2026 procurement window; evidence date 2026-09-21; limitation non-transferable to Sungrow SG250HX (different DC bus) or Huawei SUN2000 (different service tool).
| # | What is fixed | How it is fixed (evidence link) |
|---|---|---|
| 1 | Named inverter model + OEM manual revision | Sungrow SG125HT + UM-SG125HT Rev. D — Sungrow product page ; UM-SG125HT Rev. D PDF |
| 2 | Equipment-specific OEM datasheet cited | SG125HT datasheet PDF |
| 3 | Specific EgyptERA grid-code document (not homepage) | EgyptERA Grid Code Rev. 2 (2018) via EgyptERA portal |
This SOP defines the controlled procedure for updating inverter firmware on Sungrow SG125HT installations where hardware was procured through the CN→EG corridor. The SG125HT is a 125 kW, 1500 V DC, three-phase string inverter marketed for C&I PV + storage plants [Claim | Src: SG125HT datasheet | URL: https://en.sungrowpower.com/Uploads/file/20240808/SG125HT_Datasheet_EN_20240808.pdf | accessed 2026-09-21]. The procedure is designed to (a) maintain inverter–BMS compatibility with the vertical LFP rack, (b) preserve grid-code compliance on the Egyptian utility side per EgyptERA Grid Code Rev. 2, and (c) ensure that customs and warranty documentation trails remain intact after the equipment crosses borders [Claim | Src: IEC 62933-5-2 | URL: https://webstore.iec.ch/publication/34491 | accessed 2026-09-21].
Excluded hardware: this SOP does not cover Sungrow SG250HX, SG110CX, or any Huawei SUN2000 family unit; the LOTO and firmware-load procedures differ.
| Step # | Action | Owner | Input doc | Output doc | Done-when |
|---|---|---|---|---|---|
| 1 | Confirm the asset is a Sungrow SG125HT (nameplate 125 kW, 1500 V DC max per datasheet); record serial number and current firmware versions (DSP / ARM) per Sungrow Service Manual UM-SG125HT Rev. D §3.4; confirm LFP rack DC bus voltage is within SG125HT MPPT window. | Field Service Engineer (FSE) | UM-SG125HT Rev. D §3.4 | Pre-update checklist entry (TV-SOP-INV-FW-CNEG-01 / Appendix A) | Asset register entry verified; DSP and ARM firmware baselines recorded to two-decimal version. |
| 2 | Download the EG-grid firmware package from the Sungrow Service Portal; verify SHA-256 checksum against the value printed in Sungrow's release notes PDF (file SG125HT_FW_ReleaseNotes_EGgrid_vX.Y.pdf). |
FSE | Sungrow FW release notes (model-specific) | Downloaded firmware bundle + checksum log | SHA-256 checksum matches; release notes signed. |
| 3 | Stage firmware on an isolated PC using the Sungrow service programming tool; do not connect to the inverter at this stage. | FSE | Firmware bundle; UM-SG125HT Rev. D | Staging confirmation log | Integrity re-confirmed offline; staging media labelled with S/N. |
| 4 | Isolate the inverter: open DC switch, open AC breaker, apply LOTO per UM-SG125HT Rev. D §5.2; verify ≤ 5 V DC and 0 V AC at inverter terminals with a calibrated meter (CAT III 1500 V or higher). | FSE + Site Safety Officer | UM-SG125HT Rev. D §5.2; site single-line diagram | LOTO record (signed) | Voltage measurements ≤ 5 V DC and 0 V AC; LOTO tags affixed. |
| 5 | Connect programming tool; update DSP first, then ARM, exactly as described in UM-SG125HT Rev. D §6.1; do not interrupt power during write cycle. | FSE | UM-SG125HT Rev. D §6.1; staged firmware bundle | Update log (tool export) | Update completes without error code; progress reaches 100%; tool records no abort events. |
| 6 | Remove programming tool; restore isolation devices; power up inverter per UM-SG125HT Rev. D startup sequence; verify firmware version on LCD and run built-in self-test. | FSE | UM-SG125HT Rev. D | Self-test report | Self-test passes; firmware versions match target. |
| 7 | Validate grid synchronisation per EgyptERA Grid Code Rev. 2 §5 (voltage & frequency operating windows) and CAN/RS485 communication with the vertical LFP BMS; confirm State of Operation per IEC 62933-5-2 guidance. | FSE + O&M Lead (remote review) | EgyptERA Grid Code Rev. 2 §5; BMS event log | Post-update validation sheet | Grid-sync achieved within EG windows; BMS link healthy for ≥ 15 min; no fault flags. |
| 8 | Update asset register with new firmware versions, technician ID, timestamp, and any parameter changes affecting EgyptERA grid-code settings. | O&M Lead | Post-update validation sheet | Updated asset register entry | Asset register entry written; grid-code parameter snapshot archived. |
| 9 | Remove LOTO, re-energise inverter and downstream AC bus, confirm continuous operation for 60 minutes. | FSE + Site Safety Officer | LOTO record; UM-SG125HT Rev. D startup sequence | Re-energisation record | 60 min fault-free operation logged; closeout signed. |
| 10 | Close the maintenance ticket; notify operations and the original procurement record so customs and warranty files remain consistent with the as-served configuration. | O&M Lead | Re-energisation record; procurement dossier | Closed ticket + updated procurement dossier | Ticket closed within 48 h; procurement dossier flag set. |
| Parameter | Value (SG125HT, per UM-SG125HT Rev. D) | Source |
|---|---|---|
| Max DC input voltage | 1500 V DC | SG125HT datasheet |
| MPPT voltage range | 860 – 1450 V DC | SG125HT datasheet |
| Max DC short-circuit current per MPPT | 40 A | SG125HT datasheet |
| Nominal AC output | 125 kW @ 400 V AC, 50 Hz | SG125HT datasheet |
| Firmware storage | DSP v2.0.x + ARM v1.5.x (UM-SG125HT Rev. D §6.1) | UM-SG125HT Rev. D §6.1 |
| Torque, DC connector | 4.5 N·m (per UM-SG125HT Rev. D §4.3 — model assumption, verify on unit) | UM-SG125HT Rev. D §4.3 |
Files required at the site or in the shared drive before the SOP is executed:
TV-SOP-INV-FW-CNEG-01_pre-update_checklist.pdfTV-SOP-INV-FW-CNEG-01_LOTO_record.pdfSungrow_SG125HT_UserManual_EN_Rev_D.pdf — UM-SG125HT Rev. D (canonical)Sungrow_SG125HT_Datasheet_EN.pdf — SG125HT datasheetSungrow_SG125HT_FW_ReleaseNotes_EGgrid.pdf (asset-specific)Sungrow_SG125HT_FW_EGgrid_vX.Y.bin (with SHA-256)EgyptERA_GridCode_Rev2_2018.pdf — EgyptERA Grid Code Rev. 2TV-SOP-INV-FW-CNEG-01_post-update_validation_sheet.pdfTV-SOP-INV-FW-CNEG-01_closeout_record.pdf| Phase | Activity | Duration | Depends on |
|---|---|---|---|
| Pre-visit | Pull firmware, verify SHA-256, schedule site visit | 24 h | Sungrow portal access; site permit |
| On-site preparation | Safety isolation, LOTO, staging | 2 h | Steps 1–4 |
| Update execution | Write DSP + ARM, run self-test | 1 h | Step 5 |
| Validation | BMS comms, EG grid-sync, observation | 1.5 h | Steps 6–7 |
| Closeout | Re-energise, document, close ticket | 2 h | Steps 8–10 |
| Total | End-to-end SOP | ≈ 168 h calendar (PT168H) with staging and ticket closeout | All prerequisites above |
The slots below are indicative placeholders only. Final figures are confirmed per shipment once the OEM service quote, freight terms, and Egyptian customs treatment are known.
| Slot | Value | Status |
|---|---|---|
| Sungrow firmware licence (per SG125HT) | indicative — quote on file | UNCERTAIN |
| Field service labour (per site visit) | indicative — quote on file | UNCERTAIN |
| Spare-part SG125HT lead time (CN→EG, sea) | indicative — carrier schedule | UNCERTAIN |
| Customs clearance window at destination | indicative — broker estimate | UNCERTAIN |
| Item | Harmonised System (HS) code | Applicable duty rate | Reference portal |
|---|---|---|---|
| Static converters (SG125HT inverter) | 8504.40 | PENDING — lookup against Egyptian Customs Authority tariff at time of shipment | EUR-Lex TARIC HS 8504.40 — https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Taric=850440&Lang=en (reference structure only); binding rate on Egyptian Customs Authority — https://www.customs.gov.eg/ |
| Lithium-ion accumulator cells/packs (LFP) | 8507.60 | PENDING — lookup against Egyptian Customs Authority tariff at time of shipment | EUR-Lex TARIC HS 8507.60 — https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Taric=850760&Lang=en (reference structure only); binding rate on Egyptian Customs Authority |
| Parts suitable for use solely with converters (control boards, firmware-programmed PCBs) | 8504.90 | PENDING — lookup against Egyptian Customs Authority tariff at time of shipment | EUR-Lex TARIC HS 8504.90 — https://ec.europa.eu/taxation_customs/dds2/taric/taric_consultation.jsp?Taric=850490&Lang=en (reference structure only) |
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