scope:

Introduction

This standard has been revised to change text, tables and figures concerning the TRV descriptions to be consistent with IEEE Std C37.04b-2008 (Amendment to IEEE Std C37.04™-1999) Entitled "IEEE Standard for Rating Structure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis" - Amendment 2: To Change the Description of Transient Recovery Voltage for Harmonization with IEC 62271-100.

The major changes implemented in this revision of the standard are listed as follows:

- The TRV capability of circuit breakers according to this amendment to IEEE Std C37.09-1999 is described by 2 or 4 parameter envelopes in place of 1-cosine and exponential-cosine envelopes.

- Everywhere the words "1-cosine" appear, they are replaced by"2-parameter."

- Everywhere the words "exponential-cosine" appear, they are replaced by"4-parameter."

- Figure 6 is redrawn to replace the exponential-cosine wave forms with 4-parameter wave forms.

- Figure 8 and Figure 9 have a label changed from "exponential-cosine" to "4-parameter."

- Test Duties 1, 2, 3, 4 and 5 are changed to T10, T30, T60, T100s and T100a respectively.

- Test Duties 4a and 4b are changed to T100s a and T100s b.

- Test Duties 6 and 7 are changed to T100s 1Ph and T100a 1Ph.

- Test Duties 8 and 9 are L75 and L90 (Short Line Faults at 75% and 90% respectively).

- Test Duty 10 is changed to STC (Short Time Current).