IEEE 638:1992 (R2006)

New IEEE Standard - Superseded.
Procedures for demonstrating the adequacy of new Class 1E transformers, located in a mild environment of a nuclear power generating station, to perform their required safety functions under postulated service conditions are presented. Single- and three-phase transformers rated 601 V to 15,000 V for the highest voltage winding and up to 2500 kVA (self-cooled rating) are covered. Because of the conservative approach used in the development of this standard for new transformers, the end-point criteria cannot be used for in-service transformers.

This standard provides requirements to demonstrate the adequacy of new Class IE transformers, located in a mild environment of a nuclear power generating station as defined in IEEE Std 323-1983 [16]1, to perform their required safety functions under postulated service conditions. This standard applies to single and three phase transformers rated 601 V to 15 000 V for the highest voltage winding and up to 2500 kVA (self-cooled rating).
The purpose of this standard is to provide specific qualification procedures for Class lE transformers to demonstrate their capability to meet the requirements of IEEE Std 323-1983 [16]. The transformer must perform its intended function under all specified service conditions.