DC systems (especially third-rail systems) are limited to relatively low voltages and this can limit the size and speed of trains and cannot use low-level platform and also limit the amount of air-conditioning that the trains can provide. This may be a factor favouring overhead wires and high-voltage AC, even for urban usage. In practice, the top speed of trains on third-rail systems is limited to 100 mph (160 km/h) because above that speed reliable contact between the shoe and the rail cannot be maintained.
DC systems ( especially third - rail systems ) are limited to relatively low voltages and this can limit the size and speed of trains and can not use low - level platform and also limit the amount of air - conditioning that the trains can provide . This may be a factor favouring overhead wires and high - voltage AC , even for urban usage . In practice , the top speed of trains on third - rail systems is limited to 100 mph ( 160 km / h ) because above that speed reliable contact between the shoe and the rail can not be maintained .
Besides speed and size what else the low voltage of DC system can effect?
Besides speed and size what else the low voltage of DC system can effect ?
air-conditioning
air-conditioning