EN 60726:2003

SECTION ONE - GENERAL
Clause
1 Scope
2 Service conditions
3 Definitions
4 Tappings
5 Connections
6 Ability to withstand short circuit
SECTION TWO - RATING
7 Rating
8 Rating plates
SECTION THREE - COOLING METHODS AND TEMPERATURE RISE
9 Identification according to cooling method
10 Temperature-rise limits
SECTION FOUR - INSULATION LEVELS
11 Insulation levels
SECTION FIVE - TESTS
12 General requirements for tests
13 Measurement of winding resistance
14 Measurement of voltage ratio and check of voltage
   vector relationship
15 Measurement of impedance voltage (principal tapping),
   short-circuit impedance and load loss
16 Measurement of no-load loss and current
17 Separate-source voltage withstand test
18 Induced overvoltage withstand test
19 Lightning impulse test
20 Partial discharge measurement
21 Temperature-rise test
22 Measurement of sound level
23 Short-circuit test
24 Tolerances
SECTION SIX - ENCLOSURES
25 Degrees of protection provided by enclosures
SECTION SEVEN - MISCELLANEOUS
APPENDIX A - Information required with enquiry and order
APPENDIX B - Climatic, environmental and fire behaviour classes
Annexes
Bibliography

Specifies requirements for dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 36 kV. The following small and special dry-type transformers are not covered by this standard: -instrument transformers (covered by EN 60185 and 60186); -transformers for static convertors (covered by EN 60084, 60119 and 60146). Where IEC standards do not exist for other special transformers, this standard may be applicable as a whole or in part.