IEC 60076-12:2008
Current
The latest, up-to-date edition.
Power transformers - Part 12: Loading guide for dry-type power transformers
Hardcopy , PDF 1 User , PDF 3 Users , PDF 5 Users , PDF 9 Users
English - French
05-11-2008
FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Effect of loading beyond nameplate rating
4.1 General
4.2 General consequences
4.3 Effects and hazards of short-time emergency loading
4.4 Effects of long-time emergency loading
5 Ageing and transformer insulation lifetime
5.1 General
5.2 Lifetime
5.3 Relation between constant continuous load and
temperature
5.4 Ageing rate
5.5 Lifetime consumption
5.6 Hot-spot temperature in steady state
5.7 Assumed hot-spot factor
5.8 Hot-spot temperature rises at varying ambient
temperature and load conditions
5.9 Loading equations
5.9.1 Continuous loading
5.9.2 Transient loading
5.10 Determination of winding time constant
5.10.1 General
5.10.2 Time constant calculation method
5.10.3 Time constant test method
5.11 Determination of winding time constant according
to empirical constant
5.12 Calculation of loading capability
6 Limitations
6.1 Current and temperature limitations
6.2 Other limitations
6.2.1 Magnetic leakage field in structural metallic
parts
6.2.2 Accessories and other considerations
6.2.3 Transformers in an enclosure
6.2.4 Outdoor ambient conditions
Annex A (informative) Ageing rate
Annex B (informative) Examples of lifetime consumptions
for 3 load regimes
Annex C (informative) List of symbols
Bibliography
IEC 60076-12:2008 is applicable to dry-type transformers according to the scope of IEC 60076-11. It provides the means to estimate ageing rate and consumption of lifetime of the transformer insulation as a function of the operating temperature, time and the loading of the transformer.
| Committee |
TC 14
|
| DevelopmentNote |
Supersedes IEC 60905. (11/2008) Stability Date: 2018. (07/2015)
|
| DocumentType |
Standard
|
| Pages |
70
|
| PublisherName |
International Electrotechnical Committee
|
| Status |
Current
|
| SupersededBy | |
| Supersedes |
| Standards | Relationship |
| IS 2026 : Part 12 : 2018 | Identical |
| NF EN 60076-12 : 2007 PR | Identical |
| NEN IEC 60076-12 : 2009 | Identical |
| CEI 14-47 : 2012 | Identical |
| UNE-IEC 60076-12:2010 | Identical |