Some notes on transformer practice with reference to standardization

This paper forms one of a series of papers on standardization initiated by The Institution. The objects of standardization and its resulting benefits have been frequently stated and reviewed in recent years, but still form the subject of debate. They comprise improved manufacturing efficiency, shorter delivery times, more economic production, the reduction of design and drafting work with conservation of technical man-power, and the stocking, interchangeability and reduction of spares. The main factors as affecting both user and manufacturer are reviewed in order to ascertain their ideas of what should and can be done. The problem and possibilities are closely related to the organization of the transformer manufacturing industry. Schemes for the standardization of electrical machinery involve three main factors: supply-system requirements, fundamental dimensions and constructional features, and detailed design. The transformer problem does not differ in kind from that relating to other classes of electrical apparatus, and the present analysis of the transformer problem follows broadly similar lines. Standardization of supply-system requirements, including ratings and electrical performance, is a natural precursor to dimensional and design standardization. Although the subject of ratings and performance is already covered by the relevant B.S. specifications, certain matters, mentioned in the paper, require reconsideration and amplification when those specifications associated with transformer practice come up for revision. The problem of dimensional standardization is examined, and suggestions are made for the standardization of fundamental dimensions to effect interchangeability of different makes of transformers and fittings, without individual manufacturers having to forgo their own detailed designs and manufacturing techniques. Some examples are given illustrating dimensional standardization already accomplished. Detailed design standardization would only be feas- ible or necessary under a scheme of manufacture involving allocation of work or centralization of manufacture. It is suggested that efforts should be made towards achieving effective standardization of supply-system requirements to suit operating conditions, and that schemes should be considered and planned jointly by the interests concerned, to secure some measure of dimensional standardization of distribution transformers and medium-size power transformers and their principal accessories.