scope:

Foreword 

(This Foreword is not a part of ANSI/IEEE C57.94-1982, IEEE Recommended Practice for Installation, Application, Operation, and Maintenance of Dry-Type General Purpose Distribution and Power Transformers.)

This recommended practice is a revision of ANSI C57.94-1956, Guide for Installation and Maintenance of Dry-Type Transformers and incorporates an expansion of the subjects of installation, application, testing and operation of dry-type transformers. Nonventilated units are specifically covered and new considerations addressed include maintenance accessibility, room requirements, audible sound control and the effect of internal pressure on sealed units.

Scope

Transformers Covered

This recommended practice covers general recommendations for the application, installation, operation and maintenance of single and polyphase dry-type general purpose, distribution, power, and auto-transformers of the following types:

1) Ventilated, indoor and outdoor, self-cooled cooled or forced air cooled

2) Nonventilated, indoor and outdoor, self-cooled or forced air cooled

3) Sealed, indoor and outdoor, self-cooled

Transformers Not Covered

This recommended practice does not apply to the following:

1) Instrument transformers

2) Step voltage and induction voltage regulators

3) Arc furnace transformers

4) Rectifier transformers

5) Specialty transformers

NOTE - Both ventilated and nonventilated transformers may be furnished with windings utilizing materials such as solid insulating material which allow or require different practices from those required in this recommended practice. In such equipment the recommendations in this recommended practice may be modified by specific manufacturer's recommendations.