Alarm Conditions; Power Fail; Overtemperature; Overvoltage - Elektro-Automatik EL 9000 B Slave serie Betriebsanleitung

3.3

Alarm conditions

This section only gives an overview about device alarms. What to do in case your device in-
dicates an alarm condition is described in section „3.6 Alarms and monitoring" on page 32.
As a basic principle, all alarm conditions are signalled optically (by LED "Error" on the front) and via the digital
interface ports. For later acquisition, an alarm counter can be read via digital interface.
Some alarms require acknowledgement before the DC input can be switched on again, in those cases where the
alarm caused to switch it off. Acknowledgement in normal master-slave operation is done on the master unit. In
other situations, like during manual operation it can be done with the pushbutton "On / Off" on the front or else by
sending a specific command via digital interface.
3.3.1

Power Fail

Power Fail (PF) indicates an alarm condition which may have various causes:
• AC input voltage too low (mains undervoltage, mains failure)
As soon as a power fail occurs, the device will stop to sink power and switch off the DC input. In case the power
fail was an undervoltage and is gone later on, the alarm will vanish from and doesn't require to be acknowledged.
Switching off the device with the power switch can not be distinguished from a mains blackout
and thus the device will signalise a PF alarm every time it is switched off. This can be ignored.
The condition of the DC input after a PF alarm during operation when the device remains pow-
ered, i.e. like after a temporary blackout, can be set up via a specific command.
3.3.2

Overtemperature

An overtemperature alarm (OT) can occur due to an excess temperature inside the device and causes it to stop
sinking power temporarily. After cooling down, the device will automatically continue to supply power, while the
condition of the DC input remains and the alarm doesn't require to be acknowledged.
3.3.3

Overvoltage

An overvoltage alarm (OVP) will switch off the DC input and can occur if:
• the connected voltage source provides a higher voltage to the DC input than set in the overvoltage alarm thresh-
old (OVP, 0...103% U
NOM
This function serves to warn the user of the electronic load optically that the connected voltage source has gener-
ated an excessive voltage and thereby could damage or even destroy the input circuit and other parts of the device.
The device is not fitted with protection from external overvoltage and may even be damaged
when not powered.
3.3.4

Overcurrent

An overcurrent alarm (OCP) will switch off the DC input and can occur if:
• The input current in the DC input exceeds the adjusted OCP limit.
This function serves to protect the voltage and current source so that this is not overloaded and possibly damaged,
rather than offering protection to the electronic load.
3.3.5

Overpower

An overpower alarm (OPP) will switch off the DC input and can occur if:
• the product of the input voltage and input current in the DC input exceeds the adjusted OPP limit.
This function serves to protect the voltage and current source so that this is not overloaded and possibly damaged,
rather than offering protection to the electronic load.
EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
)
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
EL 9000 B Slave Series
www.elektroautomatik.de
ea1974@elektroautomatik.de
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