Reference Manual

Unit Description, PSU 1200 W
Control and Supervision Circuits
The control and supervision circuits support:
•
load sharing between parallel units
• remote on/off
• alarms
The output voltage can be adjusted between 22 V to 29 V DC. The
control and supervision is achieved through an optical signal interface
connector on the front of the PSU.
15.2.2 Functions
The PSU DC has the following functions:
• Communication
• Handling Alarms
• Voltage adjustment
•
Power Limitation
Communication
The PSU communicates with its superior unit (DXU) through an optical
interface. The PSU is controlled and supervised through this interface.
In the event of communication failure, the PSU continues working with
default values.
Alarms
The following alarms are detected in the converter and are then
forwarded to the DXU, and an indicator is illuminated on the PSU front:
• Converter failure
•
Input fault
•
Input undervoltage
•
Input overvoltage
• Output overvoltage hardware alarm
• Output overvoltage software alarm
• High internal temperature
• Power limit
• Short circuit/overload for more than one minute
Voltage Adjustment
The desired value of the output voltage of the rectifier is set by the
ECU function in the DXU. The PSU has a default value of 27.2 V. The
DXU adjusts the individual PSU voltage to maintain the required
system voltage.
EN/LZT 720 0008 P2A
2001-11-28
191 (485)
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Preliminary