Railway vehicle main circuit device

A main circuit device is arranged in a railway vehicle and includes a unit frame 15 which houses a unit switch 4a, 4b and at least one resistor 13. The unit switch and the resistor(s) are disposed in a vertical position, with the unit switch located towards the side of the vehicle and the resistor(s) located towards the centre of the vehicle. The main circuit device may be suspended across an underfloor portion of the vehicle and may include a plurality of unit frames, each housing a unit switch and a resistor. A low voltage interface side of the switch may be located towards the side of the vehicle and a high voltage interface side of the switch may be located towards the centre of the vehicle. A conductive bar may be connected to the high voltage interface of the switch and the high voltage interface may be set at a position above the charging resistor via the conductive bar. The unit frame may be disposed within, and detachably fixed to, a housing of a line breaker box or a housing of an inverter device. By installing the unit switch and resistor(s) in a unit frame, assembly and connection work can be carried out and size reduction can be achieved.