BS 7806:1995

National foreword
Foreword
SECTION ONE - GENERAL
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 Rating
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 (principle 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 Low temperature test
25 Thermal shock test
26 Tolerances
SECTION SIX - ENCLOSURES AND SAFETY REQUIREMENTS
27 Degrees of protection provided by enclosures
28 Protection against direct contact
29 Earthing terminal
SECTION SEVEN - MISCELLANEOUS
30 Electromagnetic compatibility (EMC)
Appendix A Information required with enquiry and order
Appendix B Environmental, climatic and fire behaviour classes
Annex ZA (normative) Trial use guide for special tests to
         prove suitability to environmental classes
Annex ZB (normative) Trial use guide for special tests to
         prove suitability to climatic classes
Annex ZC (normative) Trial use guide for special tests to
         prove suitability to fire behaviour classes
Annex ZD (informative) Installation and safety of a dry-type
         transformer
Figures
Tables

Specifies cooling methods, temperature rise limits, insulation limits, test methods and degrees of protection by enclosures.