50123p7s1 fm BRITISH STANDARD BS EN 50123 7 1 2003 Railway applications — Fixed installations — D C switchgear — Part 7 1 Measurement, control and protection devices for specific use in d c traction s[.]
BRITISH STANDARD Railway applications — Fixed installations — D.C switchgear — Part 7-1: Measurement, control and protection devices for specific use in d.c traction systems — Application guide The European Standard EN 50123-7-1:2003 has the status of a British Standard ICS 29.130.99; 29.280 12&23 return circuit I> insulating material earth Figure 4a – Frame connected to earth U> I> insulating material return circuit earth Figure 4b – Frame connected to the return circuit insulated floor ≥ 2m U> earth Figure 4c – High impedance system Figure – Frame fault protection systems