| Part 2 | D.C. circuit breakers, |
| Part 3 | Indoor d.c. disconnectors, switch-disconnectors and earthing switches, |
| Part 4 | Outdoor d.c. disconnectors, switch-disconnectors and earthing switches, |
| Part 5 | Surge arresters and low voltage limiters for specific use in d.c. systems, |
| Part 6 | D.C. switchgear assemblies, |
| Part 7-1 | Measurement, control and protection devices for specific use in d.c. traction systems – Application guide, |
| Part 7-2 | Measurement, control and protection devices for specific use in d.c. traction systems – Isolating current transducers and other current measuring devices, |
| Part 7-3 | Measurement, control and protection devices for specific use in d.c. traction systems – Isolating voltage transducers and other voltage measuring devices |
EN 50123-1:2003