These resistive load units make it possible to test auxiliary converters and DC battery-charging units in train carriages for correct function while under load. Since they often have to be used in large halls, the supplies can be carried by vehicles via a shaft to the train carriage to be tested. A 20-metre mains lead is supplyd with plug with earthing contact. The resistance steps are connected to safety laboratory sockets. The individual stages can be switched on and off while under load. Operation and display are on an inbuilt panel. This equipment can of course be designed with other technical parameters to suit a customer‘s wishes.