Bus duct classification turned on the product's true nature as an insulated electrical conductor under Heading 85.44.

Bus ducts were treated as insulated electrical conductors because their true nature and function, not the bare character of the bus bars alone, determined classification. A bus duct comprises bus bars housed in an insulated box-like enclosure for carrying electrical current between generating and distribution equipment, which brought it within Tariff Heading 85.44 rather than Heading 85.37. The Revenue's classification view succeeded, the impugned classification was set aside, and the Revenue's appeals were allowed.

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Issues: Whether bus ducts are classifiable under Tariff Heading 85.44 as insulated electrical conductors, or under Tariff Heading 85.37 as classified by the lower authorities.

Analysis: The product in dispute was bus duct and not bus bar. A bus duct consists of bus bars placed in an insulated box-like arrangement and is used for carrying electrical current between generating and distribution equipment. The reasoning that bus bars themselves were not insulated did not address the true nature of the product. The electrical conductor may take the form of bars, and the insulated enclosure and functional character brought the product within the scope of other insulated electrical conductors.

Conclusion: Bus ducts were held classifiable under Tariff Heading 85.44 and not under Tariff Heading 85.37; the Revenue's contention succeeded.

Final Conclusion: The impugned classification was set aside and the Revenue's appeals were allowed.

Ratio Decidendi: For tariff classification, the true nature and function of the composite product must be considered; a bus duct comprising bus bars in an insulated enclosure is an insulated electrical conductor classifiable under Heading 85.44.

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