Train preheating system
An electrical train preheating system is a device that is used to supply parked trains or wagons with electricity at the voltage of the train busbar (in Germany , Austria and Switzerland : 1000 V 16.7 Hz alternating current , single-phase) without the need for a locomotive is.
This device is mainly used to preheat or air-condition the parked cars so that they are available at the correct temperature the next time they are used. If trains are parked for longer in winter, such as over the weekend, the control of the train preheating system ensures that the temperature in the wagons does not drop below freezing point and keeps it constant at around 5 ° C. If frost-free conditions could not be guaranteed, the vehicles would have to be drained and refilled before the next use.
In modern cars, the vehicle batteries are no longer charged by an axle generator, but by a charger from the train busbar. Because of the effective supply in the state, such vehicles only have about half the battery capacity of comparable vehicles with generator supply. These wagons must be connected to the train preheating system if they are parked for a longer period, otherwise permanent consumers will discharge the battery.
technical realization
The electrical energy is obtained either from the catenary (contact wire) (15 kV , 16.7 Hz ) or from the power supply network (10, 15, 20 or 25 kV, 50 Hz). A transformer supplies all outputs of the switchgear with a voltage of 1000 V. The power per branch is up to 800 kVA in common systems . Both devices procured specifically for this purpose and decommissioned electric locomotives, so-called heating locomotives , are used as transformers.
Each exit leads from the switchgear house to a so-called heating stick. This usually consists of three units: the control column, a predetermined breaking point and a blind socket stand.
The predetermined breaking point prevents major damage to the system if the train is accidentally moved despite the cable being connected. It is designed in such a way that the heating cable can be torn off by the moving train without causing damage to the stationary system that is difficult to repair. It usually works in such a way that the cable end of the flexible heating cable is pulled straight out of the connection point through guides. In Switzerland, particularly narrow control columns with an integrated predetermined breaking point are used. These have not yet been approved by DB Energie in Germany .
If the system is switched on and under voltage, caution is required, as the plug, as soon as it is removed from the dummy socket, has no direct contact protection.
In the past, cables with control or pilot contacts were used (it is only switched on when the plug is in the vehicle socket). These control lines were unable to cope with the high mechanical loads, so that only a live cable is used again. There are only a few companies that build train preheating systems; Goth Elektrotechnik in Berlin and AST from Bavaria join z. Z. as a system supplier. Within the DB Group , the DB Energie subsidiary is responsible for operating train preheating systems.
