scope:

This Defence Standard (DEF STAN) and related documents apply to particular requirements for the design, performance, construction, marking and testing of dry-type double-wound, naturally air cooled power transformers for HM Surface Ships and Submarines.

The term 'transformer' is used in this DEF STAN to refer to inductors and induction regulators, as relevant, where these equipments are not directly mentioned. The System Requirement Document (SRD) is to specify the type of equipment required.

A number of transformers designed in accordance with this DEF STAN are already in service. Before designing a new transformer, advice is to be sought from Marine Electrical Systems (MLS) 2 on the suitability of an existing design.