Guide for using fundamental definitions for ~--r-7slons like 're itl'g'rated' etc® on the field of

EEC-TC34 'Lart.i:,^- . u related -ik _ .s^'.

Introduction

IEC standards and specifications on the field of TC34- have been drafted and published over the past decades, some of

them are more than 50 years old.

They have been changed in lay-out and technical contents due to the different state of technical airs over the time being the

reasons for many amendments, supplements and -in most s- new editions (up to 6 editions).

During the long time of existence of these publications, definitions for technical characteristics have been changed and new

definitions have becfor newly introduced characteristics, The definitions are based on the experience and

habits of the expem who considered and introduced them to their best knowledge and understanding and are influenced by

the technical 'genius of their period' in which they were created. Thus it is not surprising that some of them deviate from the

definitions in the International Electrotechnical Vocabulary (1EV), the official vocabulary of the IEC.

Such deviations have been considered by various TC34 committees over the past years with the result that the definitions

given in the 1EV (slightly amended in one case) are sufficient for the work within TC34 and no nfor additional definitions (e.g. 'objective') exists. A Co ttee Draft -34(Secretariat)30- emerged from these considerations and has been positively voted by a t majority of the National Committees.

Consequently, TC34 'Chairmen and Secretaries, at their meeting in October 1992 at Bregenz, Austria, concluded that four

fundamental definitions should strictly be followed in all future standards of this Technical Committee.

2 Fundamental definitions

2.1 Nominal Value (IEV-151-04-01)

A suitable approximate quantity value used to designate or identify a component, device or equipment.

2.2 Limiting value (IEV-151.04-02)

In a specification the greatest or smallest admissible value of one of the quantities.

2.3 Rated value (IEV-151-04.03)1

A quantity value for specifi ed operating conditions of a component , device or equipment. The value and conditions are

specified in the relevant standard or assigned by the manufacturer or responsible vendor.

2.4 Rating (1EV-151-04-04)

The set of rated values and operating conditions.

3 Application

3.1 The fundamental definitions specified above shall be applied in all future Committee Drafts, Draft International Standards and publications on the field of TC34.

3.2 The expression 'objective' value (current, voltage, ....) shall no longer be applied.

3.3 The relevant Sub Committees / Working Groups shall decide when and at which ooaasion existing publications and

documents will be aligned to the ental definitions.

3.4 In order to avoid confusion, only total all ent of publications shall be made. Partial alignment at the occasion of

amendments and supplements shall not be made.

3.5 The fundamental definitions n- A not be always verbatim and Sub Committees / Working Groups may decide on

editorial deviations if felt However, such deviations shall not change the sense of the fundamental

definitions.

3.6 In addition to the fundamental definitions other expressions may be used on the d ision of the relevant Sub Committee / Working Group if the application and/or testing practice require this. Such expressions shall be unambiguously

defined in the relevant specification.

Chairman of TC34

A slight amendment of the original definltion 'A quan&y value asslQned nerdy by a man cturer, for a app d operating Condon of a

component, device or equl nr is felt nooessary and will be proposed to the relevant TC/SC.

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