User manual

Page 78
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
• If the master unit is switched off on the AC side (power switch, supply undervoltage) and comes back later, it
willautomaticallyinitialisetheMSsystemagain,ndingandintegratingallactiveslaves.Inthiscase,MScan
be restored automatically.
• Ifaccidentallymultipleornounitsaredenedasmasterthemaster-slavesystemcannotbeinitialised.
In situations where one or multiple units generate a device alarm like OV, PF or OT 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 particu-
lar alarms can be read from the slave units displays. This also applies for remote control or remote supervision,
because the master can only report the most recent alarm.
• 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 OC alarm though the global OC limit of the MS system
was not reached. The same can occur with the OP alarm.
3.11.2.7 Important to know
In case one or several units of a parallel system are not going to be used and remain switched
off, depending on the number of active units and the dynamics of the operation it may become
necessary to disconnect the inactive units from the Share bus, because even when not powered
the units can have a negative impact on the Share bus due to their impedance.