According to IEEE C57.12.00, a durable, metal, name plate shall be affixed to each transformer by the:

According to IEEE Std C57.12.00-2021, Section 5.12, "Nameplates," it is explicitly stated that the manufacturer is responsible for affixing a durable nameplate to each transformer. This nameplate serves as the primary source of essential technical information, including ratings, connections, and impedance, which is critical for the transformer's safe installation, operation, and maintenance throughout its service life. The standard mandates that this plate be made of a material suitable for the environment and be permanently attached to the equipment.

(Assuming other options were Owner, Installer, and Inspector)

Owner: The owner is the end-user or asset holder, responsible for operation and maintenance, not the initial manufacturing and labeling process.

Installer: The installer is responsible for the physical placement and connection of the transformer at the site, following the manufacturer's instructions on the nameplate.

Inspector: The inspector's role is to verify that the transformer and its installation, including the nameplate, comply with applicable standards and specifications.

1. IEEE Std C57.12.00-2021, IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers.

Section 5.12, Nameplates: "A durable nameplate, made of metal or other material suitable for the environment, shall be permanently affixed to each transformer by the manufacturer..." This clause directly assigns the responsibility to the manufacturer.

2. U.S. Department of the Interior, Bureau of Reclamation, Transformers: Basics, Maintenance, and Diagnostics, (2005).

Chapter 2, Transformer Basics, Section 2.10 Nameplate Data: "The transformer manufacturer provides a nameplate that is a summary of the transformer electrical characteristics." This government publication, which aligns with industry standards, confirms that the nameplate is a manufacturer-provided component.

3. Short, T. A., Electric Power Distribution Handbook, Second Edition, CRC Press, (2014).

Chapter 4, Distribution Transformers, Section 4.2.1 Nameplate: "All transformers have a nameplate that gives the ratings and other important information. IEEE Std C57.12.00-2010 specifies the information that must be on the nameplate." This peer-reviewed handbook reinforces that the nameplate is an integral part of the manufactured transformer as specified by the standard.