BSMI requirements for USB power supplies with EPR specifications
The maximum output of an EPR (Extended Power Range) power supply can reach 240W, falling under the PS3 rating specified in Chapter 6 of CNS 15598-1. Therefore, products connected to this power supply must have a fire-resistant casing. According to the resolution of Item 2 of the October 2025 Information and Audio-Visual Product Testing Technology Consistency Seminar minutes: "If a product's nominal output power is greater than 100W with EPR, it belongs to the PS3 rating. Taking USB output interfaces as an example, manufacturers should still provide a dedicated output cable to consumers, and the product test report should control the brand and type of this output cable, and the user manual should specify the name/brand/model of the restricted terminal equipment."
Regarding dedicated output cables, the guidelines presented at the Information and Audio-Visual Product Testing Technology Consistency Seminar in March 2026 mentioned that if a vendor does not provide a dedicated output cable to consumers, the following documents must be submitted:
(I) A designated safety laboratory should confirm and detail in its safety report whether there is a special agreement mechanism between the power supply and the dedicated output cable. Only with this special agreement mechanism can the output power exceed 100W; otherwise, it cannot exceed 100W. This is to prevent consumers from mistakenly using cables without this special agreement, yet the power supply output still exceeds 100W. Furthermore, the brand and type of the dedicated output cable should still be controlled in the product test report, and it can be listed as an optional accessory.
(II) The certificate holder of the power supply should provide a business-to-business (B to B) declaration of sale to the exclusive channel or end-system vendor. Any subsequent additions or deletions should be approved.
(III) The certificate holder for the power supply should provide guidance to consumers on how to purchase the corresponding dedicated output cable for the power supply, both in the product manual and on the websites of distributors or end-system providers.
BTL is currently a BSMI-accredited laboratory, providing comprehensive testing services to manufacturers and issuing relevant accredited test reports to facilitate product market entry. Please contact BTL's Safety Division for inquiries.
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