FOREWORD
1 Scope
2 Normative references
3 Definitions
4 Service conditions
4.1 General
4.2 Normal service conditions
4.3 Electromagnetic compatibility (EMC)
4.4 Provision for unusual service conditions
4.5 Transport and storage conditions
5 Tappings
6 Connections
7 Ability to withstand short circuit
8 Rating
8.1 General
8.2 Rated power
8.3 Preferred values of rated power
8.4 Operation at higher than rated voltage
8.5 Operation with fan cooling
8.6 Operation in an enclosure
9 Rating plate
9.1 Rating plate fitted to the transformer
9.2 Rating plate fitted to the transformer enclosure
10 Identification according to cooling method
10.1 Identification symbols
10.2 Arrangement of symbols
11 Temperature-rise limits
11.1 Normal temperature-rise limits
11.2 Reduced temperature rises for transformers designed
for high cooling air temperatures or special air
cooling conditions
11.3 High altitude temperature rise correction
12 Insulation levels
12.1 General
12.2 Transformers for use at high altitudes
13 Climatic, environmental and fire behaviour classes
13.1 Climatic classes
13.2 Environmental classes
13.3 Fire behaviour classes
13.4 Test criteria for climatic, environmental and
fire behaviour classes
14 General requirements for tests
15 Measurement of winding resistance (routine test)
16 Measurement of voltage ratio and check of phase
displacement (routine test)
17 Measurement of short-circuit impedance and load loss
(routine test)
18 Measurement of no-load loss and current (routine
test)
19 Separate-source AC withstand voltage test (routine
test)
20 Induced AC withstand voltage test (routine test)
21 Lightning impulse test (type test)
22 Partial discharge measurement (routine and special
test)
22.1 General
22.2 Basic measuring circuit (typical only)
22.3 Calibration of the measuring circuit
22.4 Voltage application
22.5 Partial discharge acceptance levels
23 Temperature-rise test (type test)
23.1 General
23.2 Methods of loading
23.3 Winding temperature-rise correction for reduced
current
23.4 Determination of steady state conditions
24 Measurement of sound level (special test)
25 Short-circuit test (special test)
26 Environmental test (special test)
26.1 General
26.2 Validity of the test
26.3 Testing procedure
27 Climatic test (special test)
27.1 Thermal shock test (special test)
27.2 Validity of the test
27.3 Thermal shock test for C1 class transformers
27.4 Thermal shock test for C2 class transformers
28 Fire behaviour test (special test)
28.1 General
28.2 Checking of corrosive and harmful gases emission
28.3 Fire behaviour test for F1 class transformer
28.4 Quantities to be measured and measuring devices
28.5 Calibration of the test chamber without test
object
28.6 Test method
28.7 Test report
28.8 Criteria for evaluating the test results
29 Tolerances
30 Protection against direct contact
31 Degrees of protection provided by enclosures
32 Earthing terminal
33 Information required with enquiry and order
Annex A (informative) Installation and safety of dry-type
transformers