User manual

Page 77
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
EL 9000 B HP Series
3.11.2.5 Operating the master-slave system
Aftersuccessfulcongurationandinitialisationofthemasterandslaveunits,thesewillshowtheirstatusinthe
displays. While the master merely shows “Master” in the status area, the slave(s) will continuously show like this,
as long they are in remote control by the master:
It means, as long as a slave unit is in control by the master, it won’t display
any set values, but actual values, and it will show the DC input status and
possible alarms.
The slaves can no longer be controlled manually or remotely, neither via the analog nor via digital interfaces. They
can, if needed, be monitored by reading actual values and status.
The display on the master unit changes after initialisation and all set values are reset. The master now displays
the set and actual values of the total system. Depending on the number of units, the total current and power will
multiply. The following applies:
• The master can be treated as a standalone unit
• The master shares the set values across the slaves and controls them
• The master is remotely controllable via the analog or digital interfaces
• All settings for the set values U,I and P (monitoring, settings limits etc.) will be adapted to the new total values
• All initialised slaves will reset any limits (U
Min
, I
Max
etc.), supervision thresholds (OVP, OPP etc.) and event settings
(UCD, OVD etc.) to default values, so these don’t interfere the control by the master. As soon as these values
aremodiedonthemaster,theyaretransferred1:1totheslaves.Later,duringoperation,itmightoccurthat
a slave causes an alarm or event rather than the master, due to imbalanced current or slightly faster reaction.
In order to easily restore all these settings after leaving MS operation, it is recommended to
make use of the user proles (see „3.9. Loading and saving a user prole“)
• If one or more slaves report an device alarm, this will be displayed on the master and must be acknowledged
there so that the slave(s) can continue operation. If the alarm had caused the DC input to be switched off then
this will be reinstated automatically by the master unit once the alarm has been acknowledged
• Loss of connection to any slave will result in shutdown of all DC inputs, as a safety measure, and the master
will report this situation in the display with a pop-up “Master-slave safety mode”. Then the MS system has to be
re-initialised, either with or without re-establishing connection to the disconnected unit(s) before.
• All units, even the slaves, can be externally shut down on the DC inputs using the pin REM-SB of the analog
interface. This can be used as some kind of emergency off, where usually a contact (maker or breaker) is wired
to this pin on all units in parallel.
3.11.2.6 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dened:
• 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 input. The slaves will fall back to single operation mode,
but also switch off their DC input. The MSP alarm can be deleted by either initialising 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 the DC part of one or more slave units is switched off due to defect, overheating etc., the whole MS system
shuts down the power consumption and human interaction is required.
• If one or more slave units are cut from AC supply (power switch, blackout, supply undervoltage) while the master
is still running and they come back later, they’re not automatically initialised and included again in the MS system.
Then the initialisation has to be repeated.
• If the DC input of the master unit is switched off due to a defect or overheating, then the total master-slave system
can take no input power and the DC input of all slaves is automatically switched off, too.