scope:

Foreword 

[This introduction is not part of IEEE Std 95-2002, IEEE Recommended Practice for Insulation Testing of AC Electric Machinery (2300 V and Above) With High Direct Voltage.]

Traditionally, the insulation of rotating machines has been tested for dielectric strength with alternating voltage. In 1952, attention was directed to testing with direct voltage. Since then, high direct voltage has been widely used. Many reports of procedure and results are found in the IEEE Transactions with expressions of widely differing opinion.

In 1957, the Insulation Subcommittee of the IEEE Rotating Machinery Committee appointed a working group to review the existing literature and to prepare a guide for the conduct and interpretation of high direct-voltage insulation tests. It was found that many methods of making the tests have been used and that there was no uniform opinion of their relative merits.

In 1971, the Insulation Subcommittee of the IEEE Rotating Machinery Committee appointed a working group to revise the existing guide to a recommended practice.

In 1996, the Materials Subcommittee of the IEEE Electric Machinery Committee appointed a working group to revise the existing recommended practice. The document has been updated in a number of respects and typical test results using the ramped voltage test method have been included.

At present there is wide usage of high direct voltage for insulation testing, but there are still areas of disagreement regarding the utility of such tests. In this recommended practice every effort has been made to state facts and to indicate what is not certain. This document gives the present opinion and evaluation of high direct-voltage insulation testing of a large number of investigators with experience in a wide area of test activities.

Many of those who have used the methods described in this recommended practice have found them to be satisfactory and a valuable addition to other test procedures. It is hoped that the use of this recommended practice will achieve more uniform results and a fuller understanding and appreciation for the benefits of the high direct-voltage dielectric test.

A general discussion of test procedures, a comparison between alternating and direct-voltage testing, and requirements for high voltage power supplies may be found in Annex A of this recommended practice. For background information on overvoltage testing, see Clause 8 of IEEE Std 56-1977 and see IEEE P62.2/ D23.^a

Participants

This document was originally developed by a working group of the Insulation Subcommittee of the IEEE Rotating Machinery Committee. The members of this working group were:

C. D. Sidway, Chair

B. R. Loxley, Secretary

^a Information on references can be found in Clause 2.

C. E. Asbury

J. S. Askey

B. M. Cain

A. W. W. Cameron

E. B. Curdts

J. L. Kuehlthau

H. M. Marsden

G. L. Moses

E. R. Scattergood

W. Schneider

H. R. Tomlinson

H. P. Walker

W. A. Weddendorf

E. S. Yates

The 1977 revision was prepared by a working group of the Insulation Subcommittee. The members were:

R. F. Sharrow, Chair

This revision was prepared by a working group of the Materials Subcommittee of the Electric Machinery Committee. The members were:

N. E. Nilsson, Chair

The following members of the balloting committee voted on this standard. Balloters may have voted for approval, disapproval, or abstention.

When the IEEE-SA Standards Board approved this standard on 20 March 2002, it had the following membership:

James T. Carlo, Chair

James H. Gurney, Vice Chair

Judith Gorman, Secretary

*Member Emeritus

J. M. Brown

A. W. W. Cameron

E. B. Curdts

R. J. Hillen

W. J. Sheets

G. Wolff

R. Bartnikas

K. Becker

J. Grant

V. Green

B. K. Gupta

M. Jacobs

W. McDermid

B. Nindra

L. Rodland

L. Rux

V. Warren

C. A. Wilson

Paul A. Anderson

William E. Anderson

Roy L. Balke

William H. Bartley

R. Bartnikas

K. Becker

Thomas H. Bishop

E. A. Boulter

Steven R. Brockschink

Stephen P. Conrad

Roger H. Daugherty

Guru Dutt Dhingra

James H. Dymond

James S. Edmonds

Franklin T. Emery

Jorge Fernandez-Daher

Nirmal K. Ghai

J. Grant

John Travis Griffith

Franklin H. Grooms

Thomas J. Hammons

Adrienne M. Hendrickson

Gary A. Heuston

Peter H. Landrieu

Antonio J. Marques-Cardoso

Walter J. Martiny

C. V. Maughan

W. McDermid Jeffrey

L. McElray Sr..

Donald G. McLaren

James R. Michalec

Gary L. Michel

Rihong Mo

Daleep C. Mohla

Glenn Mottershead

Arthur S. Neubauer

N. E. Nilsson

James A. Oliver

Madan Rana

R. V. Rebbapragada

Jesus Martinez

Rodriguez

Charles M. Rowe

James A. Ruggieri

L. Rux

Maurice A. Secrest

John Shea

Daniel Slomovitz

Greg C. Stone

Qi Su

James E. Timperley

Paul Dieter Wagner

V. Warren

Karim Younsi

H. Zhu

Sid Bennett

H. Stephen Berger

Clyde R. Camp

Richard DeBlasio

Harold E. Epstein

Julian Forster*

Howard M. Frazier

Toshio Fukuda

Arnold M. Greenspan

Raymond Hapeman

Donald M. Heirman

Richard H. Hulett

Lowell G. Johnson

Joseph L. Koepfinger*

Peter H. Lips

Nader Mehravari

Daleep C. Mohla

William J. Moylan

Malcolm V. Thaden

Geoffrey O. Thompson

Howard L. Wolfman

Don Wright

Also included is the following nonvoting IEEE-SA Standards Board liaison:

Alan Cookson, NIST Representative

Satish K. Aggarwal, NRC Representative

Andrew D. Ickowicz

IEEE Standards Project Editor

Scope

This recommended practice provides uniform methods for testing insulation with high direct voltage. It applies to stator (armature) windings of ac electric machines rated 2300 V or higher. It covers acceptance testing of new equipment in the factory or in the field after installation, and routine maintenance testing of machines that have been in service.