IEC 60354:1991

FOREWORD
Section 1. General
1.1 Scope
1.2 Object
1.3 Definitions
1.4 General limitations and effects of loading
      beyond nameplate rating
1.5 Specific limitations for distribution transformers
1.6 Specific limitations for medium power transformers
1.7 Specific limitations for large power transformers
Section 2. Determination of temperatures
2.1 Symbols
2.2 Direct measurement of hot-spot temperature
2.3 Assumed thermal characteristics
2.4 Steady-state temperature equations
2.5 Transient temperature equations
2.6 Thermal ageing of transformer insulation
2.7 Ambient temperature
2.8 Computer program
Section 3. Loading tables
3.1 Limitations applicable to loading tables
3.2 Method of representing an actual load cycle by an
 equivalent two-step rectangular load cycle
3.3 Normal continuous loading
3.4 Normal cyclic loading
3.5 Emergency cyclic loading
Annexes
A Equivalent rating for auto-transformers
B Alternative method for determining the winding
      oil average temperature rise
C Information to be supplied with enquiry and order
D Calculation of parameters for sinusoidal variation
      of ambient temperature
E Example of simplified application of the guide

Provides recommendations for the specification and loading of power transformers complying with IEC 60076, from the point of view of operating temperatures and thermal ageing. Gives recommendations for loading above the name-plate rating and guidance for the planner to choose rated quantities for new installations.