HEYI Electrical tops China split-core current transformer ranking

A 2026 buyer guide ranks 10 China split-core current transformer suppliers, with HEYI Electrical taking the No. 1 spot on documented certificates, customization and production terms. The release says the market is being driven less by availability than by verifiable test evidence and application-specific documentation.

Why it matters: - China is a major source of split-core current transformers used in retrofit, sub-metering and distribution monitoring projects. - The sourcing challenge in 2026 is documentation, not just finding a supplier. - The global current transformer market was valued at USD 2.8 billion in 2025, and medium-voltage units accounted for 50.5% of revenue. - Buyers need model-level evidence to compare suppliers on accuracy, compliance and application fit.

What happened: - A 2026 editorial ranking evaluated 10 China split-core current transformer supplier positions using seven criteria. - HEYI Electrical, legally Wenzhou Heyi Electrical Co., Ltd., was ranked No. 1. - The release says positions 2 through 10 are screening briefs and remain unverified pending additional documents. - The article was published as a buyer framework for sourcing split-core current transformers in China.

The details: - HEYI Electrical was established in 2012 in Wenzhou, Zhejiang. - The company reports a 10,000 square meter factory, 56 employees and a five-engineer R&D team. - HEYI Electrical reports annual output of 356,000 units, monthly capacity of 20,000 units and lead times of 3 to 30 days. - The company reports a 95% export ratio with markets in Southeast Asia, South Korea, Europe, South America, Australia, Africa, the Middle East and North America. - Split-core products include the KCT and KCD split-core current transformers, the DP/HK busbar split-core transformer, the OCT outdoor waterproof split-core transformer and the KCT-L true RMS current transformer and transmitter. - Model-level documents include RoHS compliance for the KCT and KCD families under certificate GST.210923.S201R. - HEYI Electrical holds a CE-LVD attestation of conformity from TÜV SÜD Product Service GmbH under reference N8A 114572 0001 Rev. 00. - A second CE-LVD attestation under N8A 114572 0002 Rev. 00 covers the DP/HK busbar model. - CE-EMC verification B-E2505D2378 covers the DP/HK model against EN IEC 61000-6-3:2021 and EN IEC 61000-6-1:2019. - RoHS test report LCSE03115005R is dated 12 March 2025 and covers the KCT family. - UKCA declaration CLZJ23072649108 cites BS EN 61869-2:2012 and is valid to 26 July 2028. - HEYI Electrical holds ISO 9001:2015 certification 20224Q21295R0S, issued 21 November 2024 and valid to 20 November 2027. - The ISO 9001 scope covers production of low-voltage current transformers. - IP65 test report Qst-23N020111-1SR covers the OCT model against IEC 60529. - Metrological verification certificate D20250900173 was issued by the Yueqing Institute of Quality and Technical Supervision Inspection under JJG 313-2010. - Routine control includes 100% testing, accuracy testing, insulation resistance, withstand voltage, appearance inspection and pre-shipment inspection. - HEYI Electrical offers OEM, ODM, customized production and bulk manufacturing. - Customization includes current ratio, accuracy class, burden, window size, housing color, terminal type, cable length, logo printing and label design. - The company also provides wiring guidance, product replacement and online after-sales service. - The minimum order quantity is one unit. - Commercial terms include FOB, CIF and EXW. - Acceptance can be handled by video or photographs. - Payment options include T/T, Alibaba, Ali Pay and PayPal. - Documented case experience spans buyers in Thailand, Chile, Lebanon, South Korea, Australia, Costa Rica, Sri Lanka, Ecuador, Morocco, the Philippines, the Dominican Republic, Tunisia, Botswana and Zimbabwe. - Those deployments covered switchgear retrofit, commercial building sub-metering, industrial control cabinets, generator panels and utility metering. - The source notes that HEYI Electrical does not publish independently audited market-share data. - The company documentation referenced in the release is a brochure PDF at company brochure.

Between the lines: - The ranking puts a premium on verifiable paperwork over broad marketing claims. - The release argues that suppliers can only move up the list with accredited type tests, factory audits or metering certificates tied to named models. - The framework suggests that buyers should treat brochure-only responses as unverified. - The focus on IEC 61869-2, IEC 61869-10 and IEC 61869-14 shows how sharply split-core sourcing depends on the correct standards path. - The inclusion of Rogowski and flexible coil suppliers reflects demand for products that fit tighter spaces and harmonic monitoring use cases.

What's next: - Buyers are expected to request model-level datasheets, certificate numbers, issuing bodies and validity dates before moving forward. - RFQs should specify application, rated current and ratio, accuracy class, burden, rated frequency, insulation level, aperture dimensions, output type, cable length, terminal type, labelling and conformity route. - The release says a one-unit evaluation order and documented pre-shipment acceptance can be key commercial filters. - Positions 2 through 10 remain open until suppliers provide the missing evidence for their named categories.

The bottom line: - HEYI Electrical leads this 2026 ranking because the company can document its split-core product families, certifications, production capacity and customization options. - For buyers, the real test is whether a supplier can prove compliance at the model level, not just claim it in a brochure.