User Manual

PSU 230 V Power Supply Unit
4.2 Handling Alarms
The following alarms are detected in the rectifier and are then forwarded to the
ECU and to an LED on the PSU front:
Table 3 Alarms
Type of alarm Type of failure
Overvoltage failure The output voltage of the rectifier has
excee
ded the alarm level.
High temperature The internal temperature of the
rectifier has exceeded the set value.
Rectifier not adjustable The rectifier output voltage cannot
be adjusted from a superior unit.
High output power The rectifier limits the power.
Main
sfailure
Inco
ming AC supply failure has been
detected.
Communication failure The PSU is not receiving signals
from the optical loop.
Rectifier failure Rectifier failures other than those
specified above have been detected.
4.3 Voltage Adjustment/Load Sharing
The desired value of the output voltage of the rectifier is set by the ECU. The
PSU has a default value of 27.2 V. The ECU adjusts the individual PSU voltage
to maintain the required system voltage.
Load sharing is achieved by the ECU when using more than 1 PSU, load
sharing of parallel PSUs is achieved by adjusting the individual voltages to
each PSU in the system.
Output voltage from the PSU is adjusted (by the ECU) to between 26.2 V and
28.5 V depending on battery temperature.
4.4 Output Overvoltage Protection
The PSU has two overvoltage monitors for the output voltage of the PSU. The
first overvoltage level is factory set at 29.0 V. The other overvoltage monitor
(30.0 V) is determined from active and passive components. When one of the
overvoltage monitors is activated, the PSU will be shut down and one attempt
to restart is performed.
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EN/LZT 720 0282 Uen R1A