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EPS Stromversorgung GmbH
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Germany
Fon: +49 821 / 570451-0
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www.eps-germany.de
PSI 10000 4U Serie
3.11.1.7
Alarms and other problem situations
Master-slave operation, due to the connection of multiple units and their interaction, can cause additional problem
situations which do not occur when operating individual units. For such occurrences the following regulations have
been defined:
•
Generally, if the master loses connection to any slave, it will generate an MSP (master-slave protection) alarm,
pop up a message on the screen and switch off its DC output. The slaves will fall back to single operation mode,
but also switch off their DC output. The MSP alarm can be deleted by either initializing the master-slave system
again. This can be done either in the MSP alarm pop-up screen or in the MENU of the master or via remote
control. Alternatively, the alarm is also cleared by deactivating master-slave on the master unit
•
If one or more slave units are cut from AC supply (power switch, blackout, supply undervoltage) and come back
later, they’re not automatically initialized and included again in the MS system. Then the init has to be repeated.
•
If the master unit is cut from AC supply (power switch, blackout) and comes back later, the unit will automati
-
cally initialize the MS system again, finding and integrating all active slaves. In this case, MS can be restored
automatically.
•
If multiple units are defined as master the master-slave system can’t be initialized
In situations where one or multiple units generate a device alarm like OVP etc. following applies:
•
Any alarm of a slave is indicated on the slave’s display and on the master’s display
•
If multiple alarms happen simultaneously, the master only indicates the most recent one. In this case, the par-
ticular alarms can be read from the slave units displays or via digital interface during remote control or remote
supervision.
•
All units in the MS system supervise their own values regarding overvoltage, overcurrent and overpower and
in case of alarm they report the alarm to the master. In situations where the current is probably not balanced
between the units, it can occur that one unit generates an OCP alarm though the global OCP limit of the MS
system was not reached. The same can occur with the OPP alarm.
