scope:

Foreword 

(This introduction is not a part of IEEE Std 1-2000, IEEE Recommended Practice-General Principles for Temperature Limits in the Rating of Electrical Equipment and for the Evaluation of Electrical Insulation.)

There is general agreement from experience that a number of service stresses influence the service life of electrical insulation in electric equipment. The purpose of IEEE Std 1-2000 is to provide guidance for the preparation of thermal-aging test procedures to determine the temperature index (TI) of electrical insulating materials (EIM) and the thermal class of electrical insulation systems (EIS).

The main changes from IEEE Std 1-1986 are as follows:

a) The title was changed from a "Standard" to a "Recommended Practice" to be consistent with the predominant verb used in the text, "should."

b) The table of thermal classification, now Table 3, was modified to include both numerical and letter designations and all currently recognized temperature classes.

c) The multifactor testing portion of Clause 8 has been deleted because it is beyond the scope of this recommended practice, which covers temperature limits.

This revision has been made with the intent of harmonization with IEC 60085-1984, Thermal evaluation and classification of electrical insulation, and IEC 60505-1999, Evaluation and qualification of electrical insulation systems. This work was done by a working group of IEEE Standards Coordinating Committee 4 (SCC4), Insulation Systems. The members of the SCC4 working group are also technical experts of IEC TC 98, Electrical Insulation Systems. TC 98 plans to draft a revision to IEC 60085-1984.

At the time this revision was completed, the SCC4 working group had the following membership:

Paulette A. Payne, Chairperson

Robert J. Mayschak

Stephen J. Watson

Richard F. Weddleton

At the time this document was approved, the IEEE SCC4 had the following membership:

Paulette A. Payne, Chairperson

R. J. Mayschak, Secretary

E. A. Boulter

George I. Duncan

S. L. Dyrnes

A. Iversen

K. N. Mathes

E. J. Vanvooren

Loren B. Wagenaar

Stephen J. Watson

Richard F. Weddleton

M. Winkeler

The following members of the balloting committee voted on this standard:

E. A. Boulter

Jerry L. Corkran

George I. Duncan

Alan M. Iversen

Tim D. Lewis

T. V. Oommen

Paulette A. Payne

William R. Simpson

Loren B. Wagenaar

Richard F. Weddleton

When the IEEE-SA Standards Board approved this recommended practice on 7 December 2000, it had the following membership:

Donald N. Heirman, Chair

James T. Carlo, Vice Chair

Judith Gorman, Secretary

Satish K. Aggarwal

Mark D. Bowman

Gary R. Engmann

Harold E. Epstein

H. Landis Floyd

Jay Forster*

Howard M. Frazier

Ruben D. Garzon

James H. Gurney

Richard J. Holleman

Lowell G. Johnson

Robert J. Kennelly

Joseph L. Koepfinger*

Peter H. Lips

L. Bruce McClung

Daleep C. Mohla

James W. Moore

Robert F. Munzner

Ronald C. Petersen

Gerald H. Peterson

John B. Posey

Gary S. Robinson

Akio Tojo

Donald W. Zipse

*Member Emeritus

Also included are the following nonvoting IEEE-SA Standards Board liaisons:

Alan Cookson, NIST Representative

Donald R. Volzka, TAB Representative

Catherine Berger

IEEE Standards Project Editor

Scope 

Guiding principles are included for the development of test procedures for

- Thermal evaluation of electrical insulating materials (EIM)

- Thermal evaluation of electrical insulation systems (EIS) .

- Thermal classification¹ of EIS for rating electric equipment

The principles are presented in the following order:

- Clause 4, General concepts

- Clause 6, Evaluation of the thermal capability of EIM

- Clause 7, Limiting temperatures and their measurement for EIS

- Clause 8, Thermal evaluation of EIS

In the application of these principles, variations are necessary to suit the widely different types of equipment and service conditions that are considered in equipment standards. When specific equipment, IEEE, or other recognized standards based on these principles are available, they should take precedence over this recommended practice.