DD ENV 50123-7.1 : 1999

National Foreword
Introduction
1. Scope
2. References
3. Definitions
    3.1 d.c. sensor
    3.2 d.c. shunt
    3.3 isolation transducer
    3.4 Hall effect sensor
    3.5 divider
4. Measurement
    4.1 General
    4.2 Current
    4.3 Voltage dividers
5. Control systems
    5.1 General
    5.2 Anti-pumping
    5.3 Auto-reclose with variable reclose time and final
         lock out
    5.4 Line test device
    5.5 Under voltage close inhibit
6. Protection systems
    6.1 General
    6.2 Protection system for line circuit breakers (L)
    6.3 Protection system for rectifier circuit breaker (R)
    6.4 Direct acting (series trip)
    6.5 Indirect acting
Annex A (informative) Electronic protection relay features
Annex B (informative) Rate of rise and delta I relay - Examples
                        for fault characteristic and setting
                        parameter selection
Annex C (informative) Bibliography on relays in use

Gives help, guidance and requirements for the design of protection, control and measuring systems in d.c. installations that are meant to give a power supply to traction systems. Identifies the characteristics and parameters of equipment which is used in the measurement, control and protection of d.c. traction systems.