ENA TS 41-10 : ISSUE 4

1 Scope
2 References
3 Equipment design
3.1 General
3.2 Metal-enclosed equipments
3.3 Interlocking
4 Service conditions
5 Ratings
5.1 General
5.2 Operational times required for 7.2 kV and 145 kV
    switchgear
5.3 Voltage transformers
5.4 Capacitors, surge arrestors, line traps and
    coupling devices
5.5 Solid and hollow insulators
6 Design and operational requirements
6.1 Operational mechanisms, ancillary equipment and
    their enclosures
6.1.1 Position indicating
6.1.2 Locak control and monitoring
6.1.3 Hydraulic and pneumatic stored energy mechanisms
6.1.4 Charged-spring stored energy mechanisms
6.1.5 Maintenance and emergency operation
6.1.6 Other mechanism requirements
6.2 Circuit-breakers and switch-disconnectors
6.2.1 Operation
6.2.2 Mechanism and control scheme
6.2.3 System lock-outs
6.3 Disconnectors and earthing switches
6.4 Portable earthing devices
6.5 Voltage transformers
6.5.1 General
6.5.2 Secondary connections
6.5.3 Capacitor voltage transformers
6.6 Current transformer and neutral equipment bushings
6.6.1 Current transformers, generally in accordance
      with BS 3938
6.6.2 Protection current transformers
6.6.3 Accommodation of current transformers in
      circuit-breakers
6.6.4 Thermal equipment
6.6.5 Neutral equipment
6.7 Pressurised air systems for operation of equipment
6.7.1 Central storage systems
6.7.2 Unit system
6.8 Finish
7 Type Test
7.1 Radio interference test
7.2 Partial discharge test
7.3 Synchronizing duty test for switch disconnectors
7.4 Noise test
Tables
1 Rated values for 7.5 kV equipment
2 Rated values for 145 kV equipment
3 Low power factor switching ratings
4.1 Circuit TRV values for 72.5 kV, 25 kA
4.2 Circuit TRV values for 145 kV, 20 kA
4.3 Circuit TRV values for 145 kV, 25 kA
4.4 Circuit TRV values for 145 kV, 31.5 kA
5 Timing requirements
6 Voltage transformer ratings at 72.5 and 145 kV
7 Characteristics of support insulators
8 Design and operational requirements
9 Current transformer characteristics
Figures
1 Relationship between DC component at contact
    separation and the time from fault interception to
    contact separation (X/R ratio = 18.85)
2 Post insulator fixings
3 145 kV disconnector and switch-disconnector fixings
4 145 kV separately mounted earth switch fixings

Establishes the required characteristics and ratings for all types of switchgear for use on 66 kV and 132 kV 50 Hz systems.