GUIDANCE CONCERNING THE PERMISSIBLE TEMPERATURE RISE FOR PARTS OF ELECTRICAL EQUIPMENT, IN PARTICULAR FOR TERMINALS
International Electrotechnical Committee
FOREWORD
INTRODUCTION
Section 1: General
1 General
1.1 Scope and object
1.2 Reference documents
1.3 Definitions
1.4 Symbols
Section 2: Theory
2 General considerations concerning the nature of
electric contact and the calculation and
measurement of the ohmic resistance of contacts
2.1 Electric contacts and connection terminals
2.2 Nature of electric contact
2.3 Calculation of contact resistance
3 Ageing mechanisms of contacts and connection terminals
3.1 General
3.2 Contacts of dissimilar metals
3.3 Oxidation ageing mechanisms
3.4 Results concerning ageing of copper contacts
3.5 Usage and precautions to be taken in the use of
contact materials
4 Calculation of temperature rise of conductors, contacts
and connection terminals
4.1 Symbolic representations
4.2 Temperature rise deltaT[s] of a conductor with respect
to the temperature T[e] of the surrounding medium
4.3 Temperature rise deltaT[o] o in the vicinity of the
contact: temperature rise of connection terminals
4.4 Temperature rise of the elementary contact points
Section 3: Application
5 Permissible temperature and temperature rise values
5.1 Ambient air temperature theta[a]
5.2 Temperature and temperature rise of various
equipment components
5.3 Temperature and temperature rise of conductors
connecting electrical equipment
5.4 Temperature and temperature rise of connection
terminals for electrical equipment - Influence
on connected conductors
6 General procedure to be followed for determining
permissible temperature and temperature rise
6.1 Basic parameters
6.2 Method to be followed for determining maximum
permissible temperature and temperature rise
Annex A - Numerical examples of the application of the
theory and other data
Annex B - Physical characteristics of selected metals
and alloys
Annex C - Physical characteristics of fluid dielectrics
Annex D - Information on the reaction of contact metals
with substances in the atmosphere
Annex E - Temperature rise of a conductor cooled by
radiation and convection in the vicinity
of a terminal
Annex F - List of symbols used in this report
Annex G - Bibliography
Provides guidance in estimating the permissible values for temperature and temperature rise of component parts of electrical equipment carrying current under steady state conditions.
| Document Type | Standard |
| Status | Current |
| Publisher | International Electrotechnical Committee |
| Committee | TC 32 |
| Supersedes |
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