Operating instructions
Technical Data
Feed/Feed-Back Units BUC 624, 625 9
Baumüller Nürnberg GmbH 5.96024.06a
2 TECHNICAL DATA
2.1 General
The Feed/Feed back Units designated BUC 624 and BUC 625 are supply converters for feeding the DC
links of BUS 62X power modules.
For control tasks there are the controller modules from Baumüller available. Thus the units can be adapt-
ed to a wide variety of requirements.
There are two types of controller.
y The BUS 6 V controller for almost all applications in constructional engineering.
y The BUS 6 T controller for highly demanding control tasks
With the digital drive controllers of the BUS 6 series, both asynchronous and synchronous motors with
different encoder systems can be driven by the same unit.
The Feed/Feed back Units are divided into two classes, 18 kW and 36 kW.
The Feed/Feed back Units are designed for wide range voltage connection between 400 V ± 10%. Start-
ing current load relief and DC link reactor are integrated into the unit.
24 VDC external (SELV with safe isolation) are necessary for operation.
2.1.1 Description of function
Inrush current limitation
If no measures are taken, the DC link capacitors lead to inadmissibly high levels of starting current inrush
when the mains is switched on. To avoid this, the starting current is limited by a charging circuit.
A current limitation device is integrated for this, which limits the charging current to approximately 2.5 A.
When an DC link voltage of 500 VDC is reached, the system deactivates the current limitation device
and generates mains contactor enable. Auxiliary contact X99:1,2 (BUC ready for use) is closed.
Feed / feed back unit
Feeding and feeding back of the DC link are implemented as a B6-IGBT circuit that is on the input side
of a line commutator. In this connection, the DC link voltage is 640 V
DC
. Due to the high dynamics, dis-
tortions in the network can occur. At each operating point, the effectivity is cos ϕ = 1.
Reset
Using X98:5,6, you can reset messages that the basic unit generated. A permanent reset (+24 V) may
not be connected. The reset signal must be pending for at least 50 ms.