ENI-SBT70 Power supply unit

PRODUCT DATA SHEET.pdf

APPLICATION

The ENI-SBT70 power supply unit with a rated output voltage of 600 V_DC is intended as a power supply to tram cars during testing of onboard electrical components. The power supply unit features a wheeled base for easy mobility.

SPECIFICATIONS

DESIGN

The power supply unit is built within a cabinet enclosure with the interior accessible from the front, beneath single doors. The transformer and the cabinet structure are mounted on a steel base plate suspended on two fixed wheels and two castors. This increases the mobility of the device. The bottom right-hand part of the cabinet enclosure features the terminal box. The front doors display the output current and voltage meters, and a basic suite of control and monitoring instruments:

• Main switch,
• ON button,
• OFF button,
• 400-600-750 VDC output voltage selector switch,
• Emergency stop device button,
• FAULT indicator lamp.

At the left-hand wall of the cabinet is a heat sink with bolt-on diode modules of a 6D rectifier, a main line contactor, and a transformer precharging relay. The back wall features a second heat sink with precharging resistors. The left-hand side wall of the cabinet carries an air vent grille for the device enclosure box. This vent ensures an efficient flow of air within the cabinet enclosure. The back wall carries an air exhaust fan. The ventilator is turned on when the rectifier heat sink temperature exceeds 70°C.

OPERATION

The power supply unit adjusts the 3 x 400 V_AC supply voltage to the preselected value (400 / 600 / 750 V) with the transformer taps, which are switched with the selector on the cabinet front. The transformer provides galvanic separation and adjustment of voltage. The transformer downstream voltage is rectified by the 6D rectifier.