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Transformer Fire Protection

Bijan Ghayour, P.E.

Course Outline

This 6-hour course outlines basic considerations and requirements for fire protection of large, mineral-oil filled power transformers. This course also offers guidance for establishing the need for the fire protection systems for smaller transformers where the risk and/or consequences of fire to other equipment and structure are unacceptable.

In addition to the primary issues of fire protection other considerations such as effective oil and water containment systems and the environmental impacts of dealing with large amounts of contaminated water is discussed.

The course materials are based entirely on the Unified States Department of the Interior, Facilities Instructions, Standards, and Techniques Volume 3-32.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.

Learning Objective

The purpose of this course is to provide guidance for the operating and maintenance engineers in operation, maintenance, diagnostics, and testing of transformer fire protection systems and associated equipment.

At the conclusion of the course the student will be familiar with the:

Intended Audience

This course is intended for operating engineers and maintenance personnel involved in the service and maintenance of transformer fire protection systems and associated equipment.

Benefit to Attendees

The student will become familiar with transformer fire protection goals and the current transformer fire protection practices. Other associated topics such as containment of transformer oil, economical and environmental impacts of a transformer fire, and outage mitigation are discussed. The course also discusses the advantages and disadvantageous of different fire protection systems. Particular attention is given to the use of ester-based insulating fluids in lieu of traditional mineral-oils, because of their added fire fighting capability and lower environmental impacts.

Course Introduction

Transformer fires are rare but the impact is great. Even though a transformer involved in a fire likely will be destroyed almost immediately, the fire's effect on adjacent equipment and structure can be mitigated by a suitable fire protection system. The contents cover the principles of the water deluge (open nozzle) systems, along with practical information and recommended schedules on maintaining and testing of these systems. This course also offers guidelines in identifying the potential problems and recommends remedial actions to be taken.

This course also discusses the alternatives to the water deluge system for transformer fire protection such as foam, gas, dry chemical and water mist systems. In particular attention is given to the use of ester-based insulating liquids in lieu of traditional mineral-based oils. Recent developments and experience with ester-based insulating fluids show great promise for reducing the likelihood of transformer fires, and thus the need for suppression and containment while minimizing environmental effects from the insulating medium.


Course Content

This course contains specific examples, with practical emphasis on the inspection, testing, and maintenance of transformer fire protection systems.

You are required to study volume 3-32, Transformer Fire Protection, published by the Unites States Department of the Interior, Bureau of Reclamation.

FIST 3-32 Transformer Fire Protection (PDF File 300MB)

(For an electronic copy of FIST 3-32 go to and then click on volume 3-32)

Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.

The following contains the outline of the FIST 3-32 of Department of Interior, Bureau of reclamation:

FIST 3-30 Transformer Fire Protection (PDF File 300MB)

Table of Contents

1- Introduction
2- Scope
3- Background
4- Transformer Fire Protection Goals
5- Transformer Fire Protection Practices.
6- Responsibility
7- Applicable Codes and Standards
8- Risk and Consequences
9- Transformer Maintenance, Diagnostics, and Condition Assessment
10- Fire Suppression System Inspection, Testing, and Maintenance
11- Transformer and Fire Suppression System Operation
12- Design Considerations
13- Oil Spill Cleanup
14- Firefighting
15- Access and Proximity
16- Incident Investigation
17- Mitigation of Outages
18- Alternative Provisions to Fire Suppression and Containment
Appendix A- Transformer Fire protection Functional Diagram
Appendix B- Ester-Based Transformer Dielectric Fluids
Appendix C- Economic Analysis Example


Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.