Winley Electric has obtained UL/cUL certification documentation under E536138 for single-phase liquid-filled pad-mounted transformers. The certified scope covers 10 to 250 kVA single-phase pad-mounted distribution transformers, with applicable standards including IEEE C57.12.00, IEEE C57.12.28 and CSA C227.3-06. This article explains the certification scope, applicable standards, key UL/cUL test items, the correspondence between certified samples and product nameplates, and the practical value of the certification for North American technical review and supplier qualification.

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Scope note: This article is based on the available UL/cUL certificates, report references and current test-item list. It does not add conclusions beyond the certificate/report information provided by UL.

1. Certificate Overview

Single-phase pad-mounted transformers are commonly used in residential distribution, light commercial loads and single-phase end-of-line distribution. For North American projects, UL/cUL certification can support compliance pre-review, technical submittals and supplier qualification.

2. Certified Scope Details

The certified model format is ZGD-B-XXX/YYY/ZZZ. The certificate defines key parameters such as rated power, high-voltage system voltage and feed type, helping customers verify model coverage during inquiry, bidding and technical review.

3. Standards Interpretation

4. UL/cUL Test Items

5. Winley Certification Case: Test Items, Certified Sample and Nameplate Correspondence

In Winley Electric’s E536138 single-phase pad-mounted transformer certification case, the documentation is organized around traceability. The UL/cUL certificates define the certified product category, applicable standards and model range. The listed test items show the key verification areas, including electrical performance, insulation, temperature rise, sealing, mechanical structure and related safety checks. The certified sample or same-series product photos help illustrate the transformer structure, while the nameplate photo supports cross-checking of the model, rated capacity, voltage, phase, frequency and serial number against the certified scope.

6. Certificate Numbers and Issue Information

7. Substantive Value: Production Consistency and Factory Surveillance

• The value of UL certification is not limited to a certificate. After certification, the manufacturing location and certified product are typically covered by UL Follow-Up Services, which are intended to confirm that UL Certified products continue to comply with the original certification requirements.

• This drives consistency control over component selection, nameplate management, assembly process, tank sealing, connection structure, factory testing and record traceability. For batch delivery, customers care not only about the tested sample but also whether subsequent shipments remain consistent with the certified sample.

8. Customer Procurement Value

9. Official Verification Links and About Winley Electric