RE: The country of origin of Medium Voltage Substation

U.S. Department of Homeland Security U.S. Customs and Border Protection National Commodity Specialist Division One World Trade Center, Suite 51.201 New York, NY 10007 U.S. Customs and Border Protection N363926 August 21, 2026 OT:RR:NC:N2:207 CATEGORY: Origin Michael Roll Roll & Harris LLP 2121 Avenue of the Stars, Suite 800 Los Angeles, CA 90067 RE: The country of origin of Medium Voltage Substation Dear Mr. Roll: In your letter dated August 2, 2026, you requested a country of origin ruling on a Medium Voltage Substation on behalf of your client, Sungrow USA Corporation. The merchandise under consideration is described as Medium Voltage Substation (MVS) which is identified by model number MVS5140-LS-US. The MVS is mainly comprised of a Smart Control Cabinet (SCC) and an oil-immersed transformer housed in an open frame container. SCC is an enclosed cabinet that contains the electrical aggregation, protection, auxiliary power distribution, monitoring, and control system of the MVS. The transformer converts low-voltage AC into medium-voltage AC when discharging electricity to the grid and steps down medium-voltage AC into low-voltage AC when charging the compatible Battery Energy Storage System (BESS). The MVS is deployed in medium to large-scale energy storage power plants functioning as a bridge between the BESS and the grid to allow a bidirectional flow of electricity to either charge the BESS or discharge power back to the grid. The unit ensures the safe integration of the BESS by executing step-up or step-down voltage conversions required for seamless charging and discharging operations within the power plant. In your submission, you state that the entire manufacturing process takes place in Thailand. The manufacturing process begins with an empty cabinet of Thai origin. It is assembled using various components from Thailand, China, and other countries. An assortment of different electrical and auxiliary components are added to the cabinet, such as lighting, emergency stop switches, smoke detectors, limit switches, circuit breakers, and single and three-phase transformers. These transformers are not related to the oil-immersed transformers but dedicated solely to supplying power to the auxiliary equipment and control system within the SCC. The completed SCC is then lowered to the open frame container where an oil-immersed transformer from either Thailand or Malaysia is attached. The oil-immersed transformer from Thailand or Malaysia is a finished transformer and does not undergo any further manufacturing. The SCC and the oil-immersed transformer are then wired to connect to each other. The finished MVS is then tested and packaged, ready for shipment to the United States.
When determining the country of origin, the substantial transformation analysis is applicable. See, e.g., Headquarters Ruling Letter (“HQ”) H301619, dated November 6, 2018. The test for determining whether a substantial transformation will occur is whether an article emerges from a process with a new name, character, or use different from that possessed by the article prior to processing. See Texas Instruments Inc. v. United States, 681 F.2d 778 (C.C.P.A. 1982). This determination is based on the totality of the evidence. See National Hand Tool Corp. v. United States, 16 C.I.T. 308 (1992), aff’d, 989 F.2d 1201 (Fed. Cir. 1993). Regarding the country of origin of the MVS, it is the opinion of this office that the oil-immersed transformer from either Thailand or Malaysia is the dominant component that provides the character of the finished article as it is the component that steps voltage up or down between the BESS and the grid. Furthermore, the addition of SCC in Thailand does not substantially transform the oil-immersed transformer as it is an ancillary component that merely aids in distributing the converted voltage from the oil-immersed transformer. As such, we find that the country of origin of the MVS is the country where the oil-immersed transformer is manufactured, which in this case is either Thailand or Malaysia. The holding set forth above applies only to the specific factual situation and merchandise description as identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations (CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and complete in every material respect. In the event that the facts are modified in any way, or if the goods do not conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2. Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic verification by CBP. This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact National Import Specialist Howard Suh at [email protected]. Sincerely, (for) James P. Forkan Director National Commodity Specialist Division