FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviations
5 Types of tap-changer
5.1 General
5.2 On-load tap-changers
5.3 Off-circuit tap-changers
5.4 Liquid-immersed tap-changers
5.5 Dry-type tap-changers
5.6 Other types
5.7 Protective devices
6 Selection of tap-changers
6.1 General
6.2 On-load tap-changers
6.3 Off-circuit tap-changers
7 Location of liquid-immersed tap-changers
7.1 Tap selectors
7.2 Diverter and selector switches
8 Fittings
8.1 Valves, air-release vents and liquid sampling devices
8.2 Liquid level gauges
8.3 Low liquid level alarms
8.4 Nameplate and other plates
8.5 Devices to aid maintenance
8.6 Dehydrating breathers
9 Field service (operation, maintenance and monitoring)
9.1 Operation
9.2 Maintenance
9.3 Monitoring in service
10 Information to be provided by the transformer manufacturer
10.1 Information required at the enquiry or order stage for
an on-load tap-changer
10.2 Information required with enquiry or order for
off-circuit tap-changers
10.3 Documentation
11 Protection and safety
11.1 Protection
11.2 Safety aspects
11.3 Immersing medium