CROSS-STANDARD public interest · Grid-tied PV inverter (storage excluded)

China-to-US Solar Inverter Compliance Gap Matrix

AI-compiled from official public sources — cross-checked by multiple AI models, not human-verified. Informational only; see disclaimer. Public-interest, source-linked comparison of common China grid-tied PV inverter documentation against US UL, FCC, IEEE 1547, and utility interconnection expectations.

Dataset 2026-06-11 Last verified 2026-06-11 20 rows

GAP MATRIX

Compliance Gap Matrix

Gap matrix
Compliance item Common China baseline United States (UL/FCC) Gap / action Source + verification date
Smart Inverter Communication Interoperability (IEEE 1547 / SunSpec Modbus) Chinese grid-tied PV inverters are typically certified to NB/T 32004 (technical requirements for PV inverters) and GB/T 19964 (PV power station grid connection). Communication interfaces commonly use Modbus RTU/TCP per manufacturer convention, but standardised smart-inverter interoperability protocols equivalent to SunSpec or IEEE 2030.5 are not broadly mandated for export products. GB/T 22239 (classified protection of cybersecurity) addresses information-system security tiering domestically but does not prescribe inverter-level communication protocols.NB/T 32004-2018 (光伏逆变器技术规范)
GB/T 19964-2012 (光伏发电站接入电网技术规定)
GB/T 22239-2019 (信息安全技术 网络安全等级保护基本要求)		 IEEE 1547-2018 requires distributed energy resources (DERs) to support communication interfaces enabling monitoring and control of grid support functions (voltage/frequency ride-through, reactive power, volt-var, etc.). California Rule 21 Phase 2/3 mandates smart-inverter advanced functions using SunSpec Modbus or IEEE 2030.5 (SEP 2) as the communication protocol for utility-interactive inverters interconnected to California distribution grids. No single federal mandate applies nationally; requirements are largely utility-tariff and state-rule driven.IEEE 1547-2018 (Interconnection and Interoperability of Distributed Energy Resources)
California CPUC Rule 21 Phase 2 / Phase 3 (Smart Inverter Requirements)
IEEE 2030.5 / SEP 2 (Smart Energy Profile 2)
SunSpec Modbus Communication Interface Specification		 Chinese-manufactured inverters commonly lack factory-enabled SunSpec Modbus register maps or IEEE 2030.5 / SEP 2 stacks required by California Rule 21 Phase 2/3 and expected under IEEE 1547-2018. Technical documentation (register maps, protocol compliance statements) is frequently absent or only available in Chinese. Retrofitting or firmware-enabling these protocols post-manufacture is possible but adds cost and re-certification risk. GB/T 22239 cybersecurity tiering applies domestically to information systems and does not align with US utility-interconnection cyber expectations.Informational only. Chinese-export grid-tied PV inverters typically require firmware/protocol updates and supplementary English documentation to meet California Rule 21 Phase 2/3 and IEEE 1547-2018 communication requirements before US interconnection approval. Consult the applicable utility tariff and a qualified interconnection engineer for project-specific obligations. IEEE2026-06-11 · unverified
Inverter Cybersecurity (UL 2900 / NIST Guidance) GB/T 22239-2019 (Classified Protection of Cybersecurity, 等级保护 2.0) is the primary domestic cybersecurity framework applied to information systems in China, covering network infrastructure, data security, and access control across five tiers. It is applied to operators of critical information infrastructure (CII) within China. Chinese inverter manufacturers may hold GB/T 22239 compliance for their internal systems but this does not equate to product-level cybersecurity certification equivalent to UL 2900 for exported devices. GB/T 37078 (cybersecurity for industrial control systems) provides additional domestic ICS guidance.GB/T 22239-2019 (信息安全技术 网络安全等级保护基本要求)
GB/T 37078-2019 (工业控制系统信息安全 第1部分：通则)		 The UL 2900 series (UL 2900-1 general, UL 2900-2-3 industrial/energy) provides a voluntary but market-recognised cybersecurity testing framework for network-connectable products including grid-tied inverters. NIST IR 8259 and NIST SP 800-82 provide guidance on IoT device cybersecurity and industrial control system security respectively. The US has no single federal law mandating inverter-specific cybersecurity certification as of the access date; however, utilities and project developers increasingly require evidence of cybersecurity controls (patch management, authentication, encrypted communications) in procurement and interconnection agreements. Executive Order 14028 (2021) and CISA advisories have raised awareness of supply-chain cyber risk for grid equipment from foreign manufacturers.UL 2900-1 (Standard for Software Cybersecurity for Network-Connectable Products)
UL 2900-2-3 (Particular Requirements for Industrial Control Systems)
NIST IR 8259 (IoT Device Cybersecurity Capability Core Baseline)
NIST SP 800-82 Rev. 3 (Guide to OT Security)
Executive Order 14028 (Improving the Nation's Cybersecurity, 2021)
CISA ICS-CERT Advisories (grid equipment supply-chain risk)		 GB/T 22239 is an operator/system-level framework applied within China and does not translate into product-level cybersecurity certification for exported inverters. UL 2900 certification (voluntary but increasingly requested) requires independent third-party penetration testing and vulnerability disclosure processes that Chinese manufacturers rarely complete for export models. US utilities and federal procurement channels (post-EO 14028) are scrutinising foreign-manufactured grid equipment for undisclosed remote-access capabilities, lack of patch lifecycles, and supply-chain transparency — areas where Chinese inverter documentation is frequently deficient. No direct Chinese equivalent to UL 2900-2-3 product certification exists for inverter exports.Informational only. Chinese-export inverters generally lack UL 2900-series cybersecurity certification and associated documentation (vulnerability disclosure policy, patch lifecycle, penetration test reports). This gap is increasingly material in US utility procurement and may affect project financing or interconnection approval in markets with heightened supply-chain scrutiny. Verify current federal and state requirements with qualified legal and engineering counsel before procurement. UL Standards & Engagement2026-06-11 · unverified
Unintentional Radiated & Conducted Emissions — FCC Part 15 Chinese manufacturers typically hold CE EMC test reports to EN 55032 (emissions) and EN 61000-3-2/3-3 (harmonics/flicker), plus GB/T 17799 series test reports. Some also test to GB 4343.1 (household/similar appliance emissions). These EN/GB test reports are NOT directly accepted by the FCC — US requires FCC-framework test reports (ANSI C63.4). For SDoC (the applicable authorization path for PV inverters), the FCC does NOT mandate use of an FCC-recognized accredited testing laboratory; however, the test must meet 47 CFR §2.948 facility requirements and the manufacturer must retain records per §2.938. An accredited lab (A2LA, NVLAP, ANAB, or PJLA) is best practice and may be required by downstream customers. Note: As of September 2025, the FCC has denied recognition of multiple China-government-controlled test labs and is actively restricting use of labs in countries without US MRAs — Chinese manufacturers should use labs in MRA-partner countries or US-based labs.GB/T 17799.4 (EMC — generic emission standard, industrial environment)
GB/T 17799.3 (EMC — generic emission standard, residential/light industrial)
EN 55032 / CISPR 32 (multimedia equipment emissions — commonly used in CE scope)
GB 4343.1 (household/similar appliance EMC emissions — not applicable to grid-tied string inverters; applicable only to household appliances per CISPR 14 scope; typically not cited for commercial/industrial PV inverters)		 Grid-tied PV inverters operating as digital devices must comply with FCC Part 15 Subpart B limits for unintentional radiators. Residential installations require Class B limits; commercial/industrial installations may qualify for Class A. Compliance is demonstrated via a Supplier's Declaration of Conformity (SDoC) supported by accredited test reports to ANSI C63.4 (radiated) and ANSI C63.4 or FCC-accepted methods (conducted). No FCC registration or pre-market approval is required, but the SDoC and test data must be retained and made available to the FCC on request.47 CFR Part 15, Subpart B (FCC Rules — Unintentional Radiators)
ANSI C63.4 (measurement methods for radiated/conducted emissions)
FCC KDB 784748 (SDoC guidance)		 Core gap: FCC Part 15 requires US-specific SDoC documentation and test reports conducted under ANSI C63.4. CE EMC reports and GB test data cannot be substituted. Class A vs. Class B classification must be determined per FCC rules (not EN 55032 category), which may require re-classification and re-testing. The SDoC label, user manual FCC notice, and responsible party (US contact) requirements are unique to FCC and have no direct analog in CN certification. On mutual recognition: the FCC has no MRA with China for equipment EMC authorization. As of September 2025, the FCC has revoked recognition of multiple Chinese-government-controlled labs and is actively moving to restrict use of labs in countries without US MRAs — Chinese manufacturers should ensure their EMC tests are performed at labs in APEC TEL MRA or EFTA MRA countries, or in the US.Gap requires action: Chinese PV inverter manufacturers must obtain new FCC-framework EMC test reports (ANSI C63.4) from an FCC-recognized accredited laboratory and prepare a US-format SDoC with a US responsible party. Existing CE or GB EMC reports are not substitutable. This is a mandatory pre-market requirement for US import/sale. FCC / US Government Publishing Office (eCFR Title 47)2026-06-11 · unverified
Industrial, Scientific & Medical (ISM) Equipment — FCC Part 18 CN manufacturers typically address ISM-band emissions through GB/T 17799.4 (generic industrial EMC emissions) and, where applicable, GB 4343 series for household/similar appliances. There is no direct CN ISM equipment regulatory category equivalent to FCC Part 18. CE-based compliance may reference EN 55011 (ISM equipment emissions), but this standard and its test reports are not accepted by the FCC. SAMR and MIIT have not issued a China-domestic ISM equipment EMC standard that maps directly to the FCC Part 18 scope; GB/T 17799 series is the closest domestic framework but addresses generic industrial emissions, not intentional ISM RF generation specifically.GB/T 17799.4 (EMC — generic emission, industrial environment)
EN 55011 / CISPR 11 (ISM equipment emissions — used in CE scope, not FCC-accepted)
GB 4343.1 (household/similar appliance EMC — not applicable to grid-tied industrial string inverters; limited to household appliances per CISPR 14 scope)		 FCC Part 18 applies to ISM equipment that intentionally generates and uses RF energy for industrial, scientific, medical, domestic or similar purposes (other than communications). PV inverters with switching frequencies or harmonics falling within ISM frequency bands (e.g., 6.78 MHz, 13.56 MHz, 27.12 MHz, 40.68 MHz) may be subject to Part 18 conducted and radiated emission limits in addition to Part 15. Part 18 sets field-strength limits at specified distances. Compliance path: verification by manufacturer; no FCC registration required for most Part 18 devices. In practice, mainstream grid-tied string inverters switch at 16–200 kHz — fundamental frequencies that are below the lowest designated ISM band (6.78 MHz). Part 18 therefore does not apply to most standard PV inverters unless high-order switching harmonics or an intentional RF-generating subsystem (e.g., a PLC communicator) creates energy within an ISM band. Manufacturers should verify harmonic profiles with an FCC-recognized lab during initial FCC compliance assessment.47 CFR Part 18 (FCC Rules — Industrial, Scientific, and Medical Equipment)
47 CFR Part 18, Subpart D (emission limits)
47 CFR §18.107 (relationship to Part 15)		 Applicability gap: Whether a specific PV inverter model falls under Part 18 (in addition to Part 15) depends on its switching frequency and harmonic spectrum — this must be determined on a model-by-model basis with an FCC-recognized lab. If Part 18 applies, CN manufacturers have no existing equivalent certification pathway; a new US-specific emissions test and manufacturer verification record is required. CE ISM reports (EN 55011) are not substitutable. In practice, most standard CN grid-tied string inverters (16–200 kHz fundamental switching frequency) do not fall within Part 18 ISM bands; Part 18 risk arises mainly if the inverter includes a PLC-based communication module or AFCI function that intentionally generates energy at ISM-band frequencies.Conditional gap: Manufacturers must confirm with an FCC-recognized lab whether Part 18 applies to their specific inverter model based on switching frequency and harmonic profile. If applicable, new US-specific testing and a manufacturer verification record are required; existing CN/CE ISM test data cannot be reused. FCC / US Government Publishing Office (eCFR Title 47)2026-06-11 · unverified
FCC Supplier's Declaration of Conformity (SDoC) — Documentation & Labeling CN manufacturers exporting under CE marking issue a EU Declaration of Conformity (DoC) referencing EN standards, with CE mark affixed to the product. For domestic China market, CCC (China Compulsory Certification) or SRRC (radio) certificates are issued by designated certification bodies; manufacturers do not self-declare in the same way. The CE DoC format, responsible party structure, and label requirements are materially different from FCC SDoC — no direct reuse is possible. There is no CN domestic equivalent to the FCC 'responsible party in the US' requirement.EU Declaration of Conformity (CE marking — EU framework, not FCC-accepted)
GB/T 30250 (product EMC marking — domestic China voluntary marking standard; not applicable to US FCC SDoC requirements; cited for completeness only)
CCC certification scheme (CNCA — compulsory, domestic China only)		 Devices subject to FCC Part 15 Subpart B (and Part 18 where applicable) must be accompanied by a Supplier's Declaration of Conformity (SDoC). The SDoC must: (1) identify the responsible party (must be located in the US or have a designated US agent); (2) reference the applicable FCC rules; (3) be supported by test records retained for 2 years after the last date of manufacture. The device must bear an FCC compliance label per 47 CFR §15.19; for devices where labeling is impractical, FCC KDB 784748 D01 (General Labeling and Notification, v09r02) and D02 (e-Labeling, v02r01) provide alternative label placement and electronic label guidance. For inverters with remote/app-based interfaces, KDB 784748 D02 electronic labeling provisions may apply — the label may be displayed on the management interface or in the companion app. The user manual must include FCC Part 15 interference notice language per §15.105. No FCC filing or pre-approval is required for SDoC devices.47 CFR §15.19 (labeling requirements)
47 CFR §15.105 (information to user)
47 CFR §2.1077 (SDoC content requirements)
47 CFR §2.1074 (responsible party for SDoC)
FCC KDB 784748 D01 (General Labeling and Notification, v09r02) — confirmed active on FCC KDB portal
FCC KDB 784748 D02 (Electronic Labeling, v02r01) — confirmed active on FCC KDB portal
FCC KDB 896810 (Supplier's Declaration of Conformity — SDoC guidance) — confirmed active on FCC KDB portal		 Documentation gap: The FCC SDoC is a US-specific self-declaration with unique format, content, responsible-party, and labeling requirements. CN manufacturers must: (a) appoint a US responsible party (importer, US subsidiary, or authorized representative); (b) create a US-format SDoC referencing 47 CFR Part 15; (c) update product labels and user manuals with FCC-specific language; (d) retain test records for 2 years. No element of the CE DoC, CCC certificate, or GB test report fulfills these requirements. This is an administrative gap that adds time and cost independent of the underlying EMC test results.Gap requires action: CN manufacturers must create a new FCC SDoC, appoint a US responsible party, and update product labeling and user manuals before US market entry. This is a mandatory administrative requirement independent of EMC test results; no existing CN or CE documentation satisfies it. FCC / US Government Publishing Office (eCFR Title 47, Part 2 Subpart J — Equipment Authorization)2026-06-11 · unverified
Grid Interconnection Framework & Primary Standard In China, PV power station grid connection is governed primarily by GB/T 19964-2024 (Technical Requirements for Connecting Photovoltaic Power Station to Power System), which sets system-level technical requirements. Inverter-level specifications are covered by NB/T 32004-2018 (Technical Specification of PV Grid-Connected Inverter). These standards are administered by the National Energy Administration (NEA) and State Administration for Market Regulation (SAMR) and are referenced in grid interconnection agreements issued by State Grid Corporation of China and China Southern Power Grid.GB/T 19964-2024
NB/T 32004-2018		 Grid-tied PV inverters interconnecting with US electric power systems must comply with IEEE 1547-2018 (Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces). IEEE 1547-2018 superseded the 2003 edition and introduced mandatory voltage and frequency ride-through categories (Category I/II/III), reactive power capability, voltage regulation participation, and enhanced anti-islanding requirements. Conformance testing is specified in IEEE 1547.1-2020. Utilities and state/AHJ authorities layer additional interconnection agreement requirements on top of IEEE 1547; UL 1741 (Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources) and its Supplement B (UL 1741 SB) provide the product-level certification pathway for grid-support functions in states such as California (Rule 21) and Hawaii.IEEE 1547-2018
IEEE 1547.1-2020
UL 1741 (including UL 1741 SB)
California Rule 21 (CPUC D.14-12-035 Phase 1; D.16-06-052 Phase 2/3; Resolution E-4898)
Utility Interconnection Agreement (utility-specific)		 IEEE 1547-2018 mandates specific ride-through categories (I/II/III) and reactive power curves that differ substantially from GB/T 19964 grid-code requirements. A product certified under Chinese standards must undergo new conformance testing per IEEE 1547.1-2020 at a NRTL-accredited laboratory to demonstrate compliance. Additionally, UL 1741 SB certification (for advanced grid-support / smart inverter functions) is separately required in California and Hawaii; no direct Chinese equivalent certification is recognised by US utilities.Chinese-certified PV inverters require full re-testing and certification to IEEE 1547-2018 / IEEE 1547.1-2020 and UL 1741 (SB where applicable) before US grid connection is permitted. Existing GB/T / NB/T certifications are not transferable to the US market. A utility interconnection agreement must also be executed with the local utility prior to connection. IEEE2026-06-11 · unverified
Voltage & Frequency Ride-Through Requirements GB/T 19964-2024 (published March 15, 2024, replacing GB/T 19964-2012) specifies low-voltage ride-through (LVRT) and high-voltage ride-through (HVRT) requirements for PV power stations on the 50 Hz Chinese grid. Under GB/T 19964-2024, PV plants must operate stably when voltage rises to 110%–135% of nominal value for defined durations. The ride-through voltage-time profile and reactive current injection requirements during faults differ from IEEE 1547 Category definitions. NB/T 32004-2018 specifies inverter-level LVRT capability. The Chinese grid operates at 50 Hz with voltage levels and fault profiles distinct from the North American 60 Hz system, making direct parameter transfer impossible without re-testing. Exact per-threshold duration tables require the full GB/T 19964-2024 standard document for confirmation.GB/T 19964-2024
NB/T 32004-2018		 IEEE 1547-2018 Section 6 defines mandatory voltage ride-through (VRT) and frequency ride-through (FRT) performance categories. Category I (default) requires the inverter to remain connected and continue operating during specified over/under-voltage and over/under-frequency events with defined clearing time windows. Category II (more stringent, for critical infrastructure or utility-specified) and Category III (most stringent) require longer ride-through durations and tighter operating bands. The standard also mandates momentary cessation and trip settings, and prohibits unintentional islanding. Specific trip settings (e.g., voltage ±10–20%, frequency 57–60.5 Hz nominal for 60 Hz grid) and clearing times are tabulated in the standard.IEEE 1547-2018, Section 6
IEEE 1547.1-2020 (conformance test procedures for VRT/FRT)		 The ride-through category structure (I/II/III) and associated voltage/frequency bands in IEEE 1547-2018 have no direct equivalent in the Chinese grid codes. The Chinese 50 Hz grid system parameters (voltage levels, fault current profiles, reactive injection curves) differ from the US 60 Hz system, meaning all VRT/FRT parameters must be re-verified via IEEE 1547.1-2020 tests. Software/firmware updates to trip settings are typically required; hardware modifications may also be needed if the inverter's grid-forming control loop was tuned for 50 Hz operation.Ride-through parameters certified under Chinese grid codes are not accepted for US interconnection. Full VRT/FRT conformance testing per IEEE 1547.1-2020 is required, and inverter firmware/hardware may need modification to meet 60 Hz US grid ride-through profiles. This is typically one of the most significant technical gaps for Chinese-made inverters entering the US market. IEEE2026-06-11 · unverified
Anti-Islanding Protection NB/T 32004-2018 Section 5 specifies anti-islanding requirements for PV grid-connected inverters in China, including passive detection (over/under-voltage and frequency relays) and active detection methods (e.g., active frequency drift). The detection time requirement under Chinese standards is generally 2 seconds for passive methods, consistent with IEEE 1547 in principle, but the specific test circuit, load conditions, and pass/fail criteria differ from IEEE 1547.1-2020. Chinese certification is conducted by accredited domestic labs; results are not mutually recognised by US NRTLs. NB/T 32004-2018 does not prescribe the specific resonant RLC load test circuit defined in IEEE 1547.1-2020; Chinese anti-islanding tests use passive over/under-voltage and frequency relay detection with active frequency drift as the primary method — the test circuit and pass/fail criteria differ from IEEE 1547.1-2020 Clause 5.7.NB/T 32004-2018, Section 5
GB/T 19964-2024		 IEEE 1547-2018 Section 8.7 requires all grid-tied inverters to detect and cease energising an unintentional island within 2 seconds of island formation. The standard mandates both passive and, where required by the utility, active anti-islanding detection methods. IEEE 1547.1-2020 specifies the conformance test procedure, including the loss-of-mains (LOM) test using a resonant RLC load. UL 1741 certifies anti-islanding performance at the product level. Intentional islanding (microgrid operation) is addressed separately and requires explicit utility agreement.IEEE 1547-2018, Section 8.7
IEEE 1547.1-2020 (anti-islanding test procedure)
UL 1741		 Although both systems require anti-islanding within ~2 seconds, the test methodologies differ. IEEE 1547.1-2020 prescribes a specific resonant RLC load test circuit that must be passed at an NRTL-accredited US lab; Chinese lab test results under NB/T 32004 are not recognised. Active anti-islanding algorithms validated for the Chinese 50 Hz grid may also behave differently on the US 60 Hz grid, requiring re-validation. UL 1741 listing is a separate product safety certification step that has no Chinese equivalent accepted by US utilities.Chinese anti-islanding certification does not satisfy US requirements. Re-testing per IEEE 1547.1-2020 at a US NRTL lab and UL 1741 listing are required. Algorithm re-validation for 60 Hz operation is advisable even if the 2-second target is nominally met under Chinese testing. IEEE2026-06-11 · unverified
Utility Interconnection Agreement & State/AHJ Approval In China, grid interconnection for PV projects requires submission of a grid connection application to the provincial grid company (State Grid or Southern Power Grid), followed by a grid access study, signing of a Power Purchase Agreement (PPA) and Grid Connection Agreement, and final acceptance inspection. The process is governed by State Grid's enterprise standards and NEA administrative procedures. There is no independent public utility commission equivalent; the grid company controls both the technical standard and the commercial approval process.NEA Management Measures for Distributed PV Power Generation Development and Construction (分布式光伏发电开发建设管理办法) — issued January 2025, replacing 2013 guidelines; administered by National Energy Administration
State Grid Corporation Enterprise Standard Q/GDW 1480-2015 (Technical Code for Connecting Distributed Resources to Distribution Networks) and Q/GDW 11784-2017 (PV inverter grid connection technical requirements) — specific numbers confirmed via State Grid enterprise standards catalogue		 Beyond equipment certification, connecting a PV system to the US grid requires execution of a formal Interconnection Agreement with the local utility (distribution-level) or ISO/RTO (transmission-level). FERC's Small Generator Interconnection Procedures (SGIP) and Large Generator Interconnection Procedures (LGIP) provide federal templates; states adopt their own rules (e.g., California's Rule 21 administered by CPUC, which also mandates UL 1741 SB for smart-inverter functions). Hawaii's Rule 14H remains Hawaiian Electric's current interconnection rule and similarly mandates IEEE 1547-2018 and UL 1741 SB. The interconnection process typically includes an application, technical review, interconnection study (for larger systems), and approval before energisation. Time to approval varies from weeks (small residential) to years (large utility-scale).FERC Order 2003 / SGIP — pro forma procedures codified at 18 CFR Part 35, Appendix G (Small Generator Interconnection Procedures, ≤20 MW); Order No. 2006 (68 FR 49845, 2003) and subsequent Orders 2003-A/B/C
FERC Order 828 (IEEE 1547 adoption mandate)
California Rule 21 (CPUC)
Hawaii Rule 14H (Hawaiian Electric / HECO) — current interconnection rule; IEEE 1547-2018 compliance required per Hawaii PUC Order Nos. 38062, 38070, 38294, 38651
Utility Interconnection Agreement (utility-specific)		 The US requires a utility-specific interconnection agreement executed before energisation, with technical requirements that vary by state and utility. Chinese grid connection approvals and agreements have no standing in the US regulatory process. For utility-scale projects, FERC-jurisdictional interconnection studies (queue position, network upgrade costs) represent a significant additional regulatory burden with no Chinese equivalent. State-specific mandates such as California Rule 21 add further requirements (UL 1741 SB) beyond the base IEEE 1547 standard.Chinese grid connection approvals and agreements provide no regulatory standing in the US. Manufacturers and project developers must independently navigate the US utility interconnection process at the federal (FERC), state (PUC/PSC), and utility level. Equipment must carry valid IEEE 1547-2018 / UL 1741 certification before a utility will accept an interconnection application in most jurisdictions. FERC (Federal Energy Regulatory Commission)2026-06-11 · unverified
NRTL Product Listing (Safety Certification) China uses a mandatory CCC (China Compulsory Certification) mark administered by CNCA/CQC for many electrical products; however, grid-tied PV inverters are not currently in the CCC compulsory catalogue. Chinese inverters typically hold GB/T 37408 or GB/T 19964 type-test reports issued by CESI or similar accredited labs, plus a China Quality Certification Centre (CQC) voluntary mark. These are not recognised by US NRTLs.GB/T 37408-2019
GB/T 19964-2012
CQC voluntary certification		 Grid-tied PV inverters sold in the US must be listed by an OSHA-recognized Nationally Recognized Testing Laboratory (NRTL) to UL 1741 (Standard for Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources). There is no single federal mark equivalent to CE; NRTL listing (e.g. UL, ETL/Intertek, CSA) is the de-facto safety gateway required by the National Electrical Code (NEC) Article 690 and enforced by AHJs.UL 1741 (Ed. 3)
NFPA 70 / NEC Article 690
29 CFR 1910.7 (OSHA NRTL recognition rule)		 CN lab reports (GB/T, CQC) carry zero mutual recognition with US NRTLs. A full UL 1741 / UL 1741 SA test campaign at an OSHA-recognised NRTL is required from scratch. Typical timeline: 4–6 months for a well-prepared product with complete documentation; 9–18 months if significant non-conformance issues are found or if the IEEE 1547.1-2020 conformance test (UL 1741 SB) is required, which alone can take 3+ months. Chinese manufacturers who hold existing IEC 62109 CB test reports may be able to use data-bridging at Intertek (ETL) or CSA Group to reduce re-testing scope, potentially shortening timelines.Chinese inverters with only GB/T / CQC certification cannot legally be installed in US projects. An NRTL listing to UL 1741 (and UL 1741 SA where grid-support functions are required) is the non-negotiable first step for US market access. U.S. Occupational Safety and Health Administration (OSHA)2026-06-11 · unverified
Utility Interconnection Approval (IEEE 1547 / UL 1741 SA) China uses GB/T 37408-2019 (Technical requirements for grid connection of photovoltaic inverters) and NB/T 32004 as the grid-interconnection technical standard, administered through the local grid company (State Grid / Southern Grid) connection agreement process. Anti-islanding and grid-support requirements differ materially from IEEE 1547-2018 Category B/C thresholds.GB/T 37408-2019
NB/T 32004-2018		 Beyond NRTL listing, the inverter must meet IEEE 1547-2018 (Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces). Most US utilities require proof of IEEE 1547-2018 compliance, typically demonstrated via UL 1741 SA (Supplement A) type-testing which covers advanced grid-support functions (volt-var, freq-watt, ride-through). Some states mandate additional utility-specific interconnection screens.IEEE 1547-2018
UL 1741 SA (Supplement A)
FERC Order 2222 (aggregated DER)
State utility interconnection tariffs (varies by state)		 GB/T 37408 anti-islanding trip thresholds and ride-through curves differ from IEEE 1547-2018 Category B requirements. A separate UL 1741 SA test is needed; GB/T reports are not accepted by US utilities. The key parameter delta: GB/T 37408 is designed for a 50 Hz / 380 V system; IEEE 1547-2018 targets a 60 Hz / 120–240 V system — frequency operating ranges and voltage trip bands are fundamentally incompatible, requiring firmware/hardware reconfiguration in addition to re-testing. This conclusion is confirmed; full table-level threshold comparison requires access to both complete standard documents.Inverters shipped with only GB/T 37408 compliance will be rejected by US utilities at the interconnection study stage. UL 1741 SA testing demonstrating IEEE 1547-2018 conformance is required before utility approval can be obtained. IEEE Standards Association2026-06-11 · unverified
California Energy Commission (CEC) Eligible Equipment Listing China has no direct equivalent state-by-state approved equipment list for inverters. The National Energy Administration (NEA) publishes recommended catalogues for photovoltaic products (目录 / 推荐目录), but these are advisory and do not gate market access the way CEC listing gates California interconnection approval.NEA photovoltaic recommended catalogues (advisory only) California requires PV inverters to appear on the CEC's Eligible Inverters List (published at GoSolarCalifornia / energy.ca.gov) to qualify for the California Solar Initiative (CSI) incentives and, more broadly, to be used in permitted PV installations that receive utility interconnection in California. CEC listing requires submission of UL 1741 (and UL 1741 SA where applicable) test data plus manufacturer declarations. Several other states reference similar approved-equipment lists administered by state energy offices or utilities.California Public Resources Code §25700 et seq.
CEC Eligible Inverters List (GoSolarCalifornia)
UL 1741 / UL 1741 SA (prerequisite for CEC submission)		 CEC listing is a separate administrative step on top of NRTL certification; a product can hold UL 1741 listing yet still not appear on the CEC list until the manufacturer submits the required application and data package to CEC. No CN equivalent process provides any shortcut.For California (and states that reference CEC lists), a separate CEC application filing is required after UL 1741 listing. Chinese manufacturers without a CEC listing cannot have their inverters installed in California PV projects even if NRTL-listed. California Energy Commission (CEC)2026-06-11 · unverified
Authority Having Jurisdiction (AHJ) Electrical Inspection & Permit China's grid-tied PV installation is regulated at the provincial / grid-company level. Projects go through a grid-company acceptance inspection (并网验收) rather than a separate municipal building inspection. Safety supervision is handled by local market regulation bureaus (质量技术监督局) for special equipment, but the AHJ multi-layer approval concept does not exist.National Grid / Southern Grid grid-connection acceptance procedures
GB 50794 (PV power station construction and acceptance)		 In the US, there is no single federal installation permit for PV systems. Every installation must obtain a building/electrical permit from the local Authority Having Jurisdiction (AHJ) — typically a city or county building department. The AHJ enforces the National Electrical Code (NEC, NFPA 70) Article 690 and requires that inverters be NRTL-listed; the AHJ may also impose additional local requirements. Final energisation requires both AHJ sign-off and utility Permission to Operate (PTO). This distributed approval layer has no CN equivalent.NFPA 70 / NEC Article 690 (adopted by most US jurisdictions)
Local building / electrical codes (varies by AHJ)
Utility interconnection agreement (PTO)		 The US system requires approval from three independent gatekeepers (NRTL, AHJ, utility) for any single installation, none of which recognise CN certifications or CN inspection records. Importers must budget time and cost for AHJ engagement on a project-by-project basis in addition to the upfront NRTL and CEC certification steps. AHJ permit review timelines vary from 24 hours to 12 weeks depending on jurisdiction; fast-track states (Florida, Texas, Arizona) using SolarAPP+ automated permitting can issue permits in 1–3 business days, while larger commercial or utility-scale projects in manual-review jurisdictions can take 4–12 weeks. Interconnection study timelines for utility-scale projects can extend to years.US market access for grid-tied PV inverters is not a single certification but a layered system: (1) NRTL listing to UL 1741/1741 SA, (2) CEC or equivalent state list where applicable, (3) AHJ permit per installation, (4) utility interconnection/PTO. All four gates must be passed; no CN certification substitutes for any of them. National Fire Protection Association (NFPA)2026-06-11 · unverified
NEC Article 690 — PV Systems (General Installation Requirements) China uses GB/T 29319 (grid-connected technical requirements for PV systems) and GB 50797 (design code for PV power stations) as the primary installation standards. These address grid interconnection parameters and general electrical safety but do not replicate the detailed prescriptive wiring methods or AHJ permit process of NEC Article 690. Inverters certified under Chinese standards (e.g., CGC/GF 004) meet CN grid requirements but carry no presumption of NEC compliance.GB/T 29319-2012
GB 50797-2012
CGC/GF 004:2020		 NFPA 70 (National Electrical Code) Article 690 governs the installation of photovoltaic systems in the United States. It covers wiring methods, disconnecting means, overcurrent protection, grounding, and system labelling for grid-tied and off-grid PV installations. Compliance is enforced at the local Authority Having Jurisdiction (AHJ) level and is effectively mandatory for any permitted residential or commercial installation.NFPA 70 (NEC) Article 690
NFPA 70 Article 690.4 — General Requirements
NFPA 70 Article 690.7 — Maximum Voltage
NFPA 70 Article 690.13 — Disconnecting Means		 NEC Article 690 is a comprehensive prescriptive code enforced by AHJ permit inspection — a regulatory mechanism absent in Chinese residential/C&I PV practice. Chinese-market inverters are not designed or labelled to satisfy NEC wiring method requirements, disconnecting means placement rules, or marking/labelling mandates. Passing a US permit inspection requires product documentation, labelling, and installation designs that conform to NEC 690, which most Chinese inverter OEMs do not provide as standard.[INFORMATIONAL] Chinese-market grid-tied PV inverters certified only to GB/T standards are not presumed to comply with NEC Article 690. US market entry requires either AHJ-accepted product documentation demonstrating NEC 690 conformance, or third-party listing to an applicable UL standard (e.g., UL 1741) which provides a pathway to NEC compliance. NFPA (National Fire Protection Association)2026-06-11 · unverified
NEC 690.12 — Rapid Shutdown of PV Systems on Buildings China has no equivalent mandatory rapid-shutdown requirement for building-integrated or rooftop PV systems. GB/T 29319, GB 50797, and the related safety standard GB 4943.1 do not mandate module-level de-energisation or firefighter rapid-shutdown control within defined voltage and time limits. Some premium Chinese inverter brands (e.g., Huawei, SolarEdge OEM) include optional rapid-shutdown features, but this is market-driven rather than regulatory. Standard Chinese residential/C&I inverter designs do not include NEC 690.12-compliant hardware or communication interfaces.GB/T 29319-2012
GB 50797-2012
GB 4943.1-2022		 NEC 690.12 (introduced 2014, significantly strengthened in 2017 and 2020 editions) requires that PV systems installed on or in buildings include a rapid shutdown function to reduce electrical hazards for firefighters and emergency responders. For rooftop arrays, conductors inside the building must de-energize to ≤30 V within 30 seconds of rapid-shutdown initiation. The 2020 NEC further requires module-level rapid shutdown: PV module output must be reduced to ≤80 V within 30 seconds within the array boundary (≤1 foot from module edges). This effectively mandates module-level power electronics (MLPE) — such as microinverters, DC optimisers, or module-level rapid-shutdown devices — or an inverter with a compliant Photovoltaic Hazard Control (PHC) system certified to UL 3741.NFPA 70 (NEC) 2020 — Article 690.12
NFPA 70 (NEC) 2017 — Article 690.12
UL 3741 — Photovoltaic Hazard Control
UL 1741 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources		 This is a hard US-market blocker. NEC 690.12 rapid-shutdown is mandatory for all building-mounted PV systems in jurisdictions that have adopted NEC 2017 or 2020 (the majority of US states). Chinese inverter designs that lack a rapid-shutdown initiator input, module-level power electronics, or a UL 3741-listed PHC system cannot pass AHJ inspection for rooftop installations without hardware redesign or the addition of third-party rapid-shutdown devices. The requirement has no analogue in Chinese regulations, so it is systematically absent from standard Chinese inverter product lines unless specifically designed for the US export market.[INFORMATIONAL] Standard Chinese-market grid-tied string inverters almost universally lack NEC 690.12-compliant rapid-shutdown capability. This is a critical gap for US rooftop PV market entry. Compliance requires either (a) inverter-integrated rapid shutdown with a listed initiator and module-level hardware meeting the ≤80 V / 30-second array-boundary requirement, or (b) a system-level UL 3741 Photovoltaic Hazard Control listing. Confirm specific product compliance with the manufacturer and the applicable AHJ before installation. NFPA (National Fire Protection Association)2026-06-11 · unverified
UL 3741 — Photovoltaic Hazard Control (PHC) System Listing There is no Chinese standard equivalent to UL 3741. China does not have a system-level photovoltaic hazard control certification framework. NB/T 32004 (technical requirements for PV grid-connected inverters) covers inverter electrical performance but does not address firefighter rapid-shutdown or PHC system certification. Chinese inverter safety certifications (CQC, TÜV CN) do not map to UL 3741 listing status.NB/T 32004-2018
CQC 3315-2016
GB 4943.1-2022		 UL 3741 (published 2021) is a UL standard for Photovoltaic Hazard Control Systems. It provides a system-level compliance pathway for NEC 690.12 rapid shutdown, allowing inverter manufacturers to obtain a listed PHC system certification that covers the entire array-to-shutdown chain. A UL 3741-listed system can satisfy NEC 690.12 without requiring individual module-level devices on every panel, provided the system is designed and installed as listed. This standard is increasingly required or preferred by AHJs as a clear evidence of NEC 690.12 compliance.UL 3741 — Photovoltaic Hazard Control (2021)
NFPA 70 (NEC) 2020 — Article 690.12
UL 1741 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources		 UL 3741 listing is a US-only certification with no Chinese counterpart. Chinese inverter manufacturers exporting to the US must independently pursue UL 3741 listing through a NRTL (Nationally Recognized Testing Laboratory) — a process that requires hardware design changes, firmware updates for rapid-shutdown communication protocols (e.g., SunSpec Rapid Shutdown), and system-level testing. Most standard Chinese inverter product lines do not carry UL 3741 listing. Without it (or an alternative NEC 690.12 compliance path via MLPE), the inverter cannot be legally installed in a permitted rooftop PV system in NEC 2017/2020 jurisdictions.[INFORMATIONAL] UL 3741 listing is absent from virtually all standard Chinese-market inverter product lines. For US rooftop PV market entry, Chinese inverter OEMs must either obtain UL 3741 PHC system listing or design systems around compliant MLPE. Confirm current UL listing status directly with the manufacturer via the UL Product iQ database (iq.ul.com) before specifying any product for a US permitted installation. UL Standards & Engagement2026-06-11 · unverified
Electrical Safety — NRTL Listing Requirement (UL 1741) for Grid-Tied PV Inverters In China, the primary national standard for grid-tied PV inverters is GB/T 37408-2019 (recommended, voluntary), which specifies technical requirements including safety, electrical performance, and EMC for grid-connected photovoltaic inverters. Voluntary third-party certification is available via CQC (China Quality Certification Centre) or CGC (China General Certification Centre). Both CQC and CGC are accredited IECEE National Certification Bodies and CB Testing Laboratories, enabling them to issue CB Scheme certificates against IEC 62109 (IEC 62109-1:2010 and IEC 62109-2:2011), the international safety standard for PV power converters. CB Scheme certificates issued by CQC or CGC are recognised in approximately 54 countries but are not accepted in the US as an alternative to NRTL listing.GB/T 37408-2019 — Technical Requirements for Photovoltaic Grid-Connected Inverters (recommended national standard)
IEC 62109-1:2010 — Safety of Power Converters for Use in Photovoltaic Power Systems — Part 1: General Requirements (via CB Scheme)
IEC 62109-2:2011 — Safety of Power Converters for Use in Photovoltaic Power Systems — Part 2: Particular Requirements for Inverters (via CB Scheme)		 In the United States, grid-tied PV inverters intended for use in workplaces or commercial installations must carry a certification mark from an OSHA-recognized Nationally Recognized Testing Laboratory (NRTL) before they may be legally installed. The governing standard is UL 1741 Ed. 3-2021, titled 'Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources'. UL 1741 incorporates anti-islanding and IEEE 1547-2018 interconnection performance requirements. Supplements UL 1741 SA (California Rule 21 grid-support functions) and UL 1741 SB (IEEE 1547-2018 conformance testing) extend these requirements for smart inverter functions. NRTLs recognized for UL 1741 include UL, Intertek (ETL), and CSA Group, among others. The NRTL program is established under 29 CFR Part 1910.7. CE marking and IEC CB Scheme certificates are NOT accepted as substitutes for NRTL listing.UL 1741 Ed. 3-2021 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources
UL 1741 SA — Supplement for Smart Inverter Functions (California Rule 21)
UL 1741 SB — Supplement for IEEE 1547-2018 Conformance Testing
29 CFR Part 1910.7 — Definition and Requirements for a Nationally Recognized Testing Laboratory
IEEE 1547-2018 — Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces		 The US requires NRTL listing to UL 1741 (tested by an OSHA-recognised laboratory under 29 CFR 1910.7). CE marking (EU self-declaration) and CB Scheme certificates (IEC 62109, issued by CQC/CGC) are NOT accepted as substitutes. Chinese manufacturers holding only GB/T 37408-2019 test reports or IEC 62109 CB certificates must additionally engage a US-recognised NRTL (e.g. UL, ETL/Intertek, CSA) to test and certify to UL 1741 before the product may be offered for sale or installation in the US.A Chinese-manufactured grid-tied PV inverter bearing only GB/T 37408-2019 test reports or a CB Scheme certificate (IEC 62109) would not satisfy the US NRTL listing requirement. NRTL listing to UL 1741 (and UL 1741 SA/SB as applicable to the target market state) is a distinct, mandatory step for the US market that has no direct equivalence pathway from existing Chinese or international certifications. [INFORMATIONAL ONLY — not a certification determination] U.S. Occupational Safety and Health Administration (OSHA)2026-06-11 · unverified
Electrical Safety — Constructional Safety Standard UL 62109-1 (Power Converter Hardware Safety) IEC 62109-1:2010 and IEC 62109-2:2011 are the international base documents for UL 62109-1. Chinese manufacturers commonly obtain CB Scheme certificates to IEC 62109-1/-2 through IECEE-accredited bodies such as CQC or CGC. The CB Scheme provides mutual recognition in approximately 54 IECEE member countries; however, it does not constitute NRTL listing and is not accepted by US authorities having jurisdiction (AHJs) or utilities in lieu of NRTL certification. GB/T 37408-2019 addresses overlapping safety topics within a broader technical requirements framework but is not harmonised to IEC 62109.IEC 62109-1:2010 — Safety of Power Converters for Use in PV Power Systems — Part 1: General Requirements (CB Scheme, via CQC/CGC)
IEC 62109-2:2011 — Safety of Power Converters for Use in PV Power Systems — Part 2: Particular Requirements for Inverters (CB Scheme)
GB/T 37408-2019 — Technical Requirements for Photovoltaic Grid-Connected Inverters (partially overlapping, voluntary)		 UL 62109-1 (2014 edition), titled 'Safety of Power Converters for Use in Photovoltaic Power Systems — Part 1: General Requirements', is a US adoption of IEC 62109-1:2010. It establishes minimum constructional and electrical safety requirements for PV power conversion equipment (PCE) operating at up to 1,500 V DC / 1,000 V AC, covering protection against electric shock, energy, fire, and mechanical hazards. In practice, NRTL testing to UL 1741 for grid-tied inverters typically incorporates or references UL 62109-1 safety criteria alongside the interconnection requirements of UL 1741. Both standards are within scope of NRTL recognition (e.g. UL, ETL). Testing to UL 62109-1 alone does not satisfy the NRTL listing requirement for grid-interactive inverters — UL 1741 listing is additionally required.UL 62109-1 Ed. 1-2014 — Safety of Power Converters for Use in Photovoltaic Power Systems — Part 1: General Requirements
IEC 62109-1:2010 (basis standard, international)		 UL 62109-1 is the US national adoption of IEC 62109-1, so the technical content is substantially aligned. However, a CB Scheme certificate to IEC 62109-1 issued by a Chinese IECEE body does NOT constitute US NRTL listing under 29 CFR 1910.7. The product must be re-tested or evaluated by an OSHA-recognised NRTL against UL 62109-1 (and UL 1741) to obtain a valid US certification mark. Intertek (ETL) and CSA Group explicitly accept existing CB test reports (no more than 3 years old) as part of NRTL listing applications — upon satisfactory review of the CB test report, certificate, and product sample, they will draft a listing report without full re-testing, at their discretion. UL LLC's policy is similar but handled case-by-case. This data-bridging reduces cost and time but does not eliminate NRTL evaluation; it is not automatic acceptance.A CB Scheme certificate to IEC 62109-1 held by a Chinese manufacturer does not replace or satisfy the US NRTL listing requirement. Re-engagement with an OSHA-recognised NRTL for UL 62109-1 (and UL 1741) evaluation is required before the product may carry a US NRTL mark. Technical content alignment between IEC 62109-1 and UL 62109-1 may reduce testing burden at the NRTL's discretion, but provides no automatic acceptance. [INFORMATIONAL ONLY — not a certification determination] UL Standards & Engagement2026-06-11 · unverified
Grid Interconnection Safety — Anti-Islanding and IEEE 1547-2018 Performance Requirements GB/T 37408-2019 includes grid interconnection performance requirements for Chinese grid-tied PV inverters, covering active/reactive power control, voltage and frequency operating ranges, and low/high voltage ride-through (LVRT/HVRT) for inverters above certain power thresholds. Anti-islanding (防孤岛) is addressed within GB/T 37408-2019 as a required protection function. The specific voltage and frequency thresholds, ride-through curves, and response time requirements in GB/T 37408-2019 are calibrated to the Chinese grid (380 V / 50 Hz) and differ materially from IEEE 1547-2018 values applicable to the US grid (120/240 V / 60 Hz): under GB/T 37408, frequency operating range is 49.5–50.2 Hz (normal) versus 57–60.5 Hz (Category I trip band, 60 Hz base) in IEEE 1547-2018; anti-islanding detection time is ≤2 s in both regimes but the test circuit and power quality pass criteria differ. Full numerical threshold comparison requires access to both complete standard documents; the directional conclusion (not interchangeable without re-testing) is confirmed.GB/T 37408-2019 — Technical Requirements for Photovoltaic Grid-Connected Inverters (voluntary; Chinese grid 50 Hz basis) IEEE 1547-2018 ('Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces') defines performance requirements for grid-tied inverters including anti-islanding protection (mandatory trip within 2 seconds of islanding), voltage and frequency ride-through, reactive power support, and abnormal voltage/frequency response. UL 1741 SB is the conformance test supplement that verifies a product meets IEEE 1547-2018 requirements; many US states (including those adopting ANSI C84.1 voltage ranges) now require UL 1741 SB listing for new grid interconnection applications. Anti-islanding detection is a mandatory safety function: a grid-tied inverter must cease energising the grid within 2 seconds when the utility supply is interrupted, to protect utility workers.IEEE 1547-2018 — Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces
UL 1741 SB — Supplement for Inverter Testing to IEEE 1547-2018
UL 1741 SA — Supplement for Smart Inverter Functions (California Rule 21, partially aligned with IEEE 1547-2018)		 GB/T 37408-2019 addresses anti-islanding and ride-through but is calibrated to the Chinese 50 Hz / 380 V grid. US utilities and AHJs require compliance with IEEE 1547-2018 (60 Hz / 120–240 V grid), verified via UL 1741 SB (or UL 1741 SA for California). Chinese inverters must be re-configured and re-tested for 60 Hz operation and US grid voltage ranges before UL 1741 SB listing can be obtained. The functional concept of anti-islanding is present in both regimes, but the specific trip thresholds, timing, and ride-through profiles are not interchangeable.An inverter compliant with GB/T 37408-2019 anti-islanding and ride-through provisions has addressed the functional concept but does not satisfy US IEEE 1547-2018 / UL 1741 SB requirements, due to differing grid frequency (50 vs 60 Hz), voltage levels, and specific trip thresholds. Hardware and firmware adaptation for the US 60 Hz grid, followed by NRTL testing to UL 1741 SB, is required. [INFORMATIONAL ONLY — not a certification determination] IEEE Standards Association2026-06-11 · unverified
Market Access — CE / CB Certificate Equivalence and NRTL Acceptance Gap Chinese manufacturers of grid-tied PV inverters typically hold combinations of: (1) GB/T 37408-2019 test reports from accredited Chinese labs, (2) IEC 62109-1/-2 CB certificates from CQC or CGC (IECEE-recognised NCBs/CBTLs), and (3) CE Declaration of Conformity for the EU market. Some also hold voluntary CQC or CGC product certifications. None of these certifications are accepted by US AHJs or utilities in lieu of NRTL listing. The CB Scheme, while internationally recognised in approximately 54 countries, explicitly excludes the United States from its mutual-recognition scope for NRTL-type listing purposes.IEC 62109-1:2010 / IEC 62109-2:2011 (CB Scheme, CQC/CGC)
GB/T 37408-2019 (voluntary Chinese national standard)
Directive 2014/35/EU LVD + CE Declaration of Conformity (EU only, not accepted in US)		 The United States has no mutual recognition agreement (MRA) with the EU or China that allows CE marking or IEC CB Scheme certificates to substitute for NRTL listing under 29 CFR 1910.7. OSHA's NRTL program requires that the specific testing laboratory performing the evaluation hold OSHA recognition for the applicable standard(s) (e.g. UL 1741, UL 62109-1). Products bearing a CE mark or a CB certificate issued outside the US by a non-NRTL body do not satisfy the NEC (NFPA 70) and OSHA requirements that authorities having jurisdiction (AHJs) and utilities enforce as conditions of installation and interconnection approval. No bilateral recognition or equivalence framework between the US and China (or the US and EU for NRTL purposes) has been established as of the access date; US-China trade relations have moved in the opposite direction under Section 301 tariffs and NDAA supply-chain restrictions, making any near-term MRA for this purpose highly unlikely.29 CFR Part 1910.7 — Definition and Requirements for a Nationally Recognized Testing Laboratory
NFPA 70 (NEC) — National Electrical Code (requires listed equipment)
UL 1741 Ed. 3-2021 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources		 The core market-access gap: CE marking (EU self-declaration) and IEC CB certificates are not accepted by US AHJs or OSHA as substitutes for NRTL listing. Chinese manufacturers entering the US market must engage an OSHA-recognised NRTL (UL, ETL/Intertek, CSA Group, TÜV Rheinland US, or others on the OSHA NRTL list) to test and certify against UL 1741 (and UL 62109-1 as applicable). This is a separate, additional certification step with no automatic equivalence or fast-track pathway from existing Chinese or international certificates. Lead times and costs should be independently verified with the chosen NRTL.CE marking and IEC CB Scheme certificates held by Chinese manufacturers do not satisfy US NRTL listing requirements. NRTL listing to UL 1741 (and UL 62109-1 where applicable) from an OSHA-recognised laboratory is a distinct mandatory requirement for the US market. There is no bilateral recognition framework between the US and China (or the EU) that provides equivalence for this purpose. [INFORMATIONAL ONLY — not a certification determination] U.S. Occupational Safety and Health Administration (OSHA)2026-06-11 · unverified

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