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EPS Stromversorgung GmbH
Alter Postweg 101 • 86159 Augsburg
Germany
Fon: +49 821 / 570451-0
Fax: +49 821 / 570451-25
www.eps-germany.de
PSI 10000 4U Serie
3.3
Alarm conditions
This section only gives an overview about device alarms. What to do in case your device indi-
cates an alarm condition is described in section “3.6. Alarms and monitoring“.
As a basic principle, all alarm conditions are signaled optically (text + message in the display), acoustically (if
activated) and as a readable status and alarm counter via the digital interface. In addition, the alarms OT and
OVP are reported as signals on the analogue interface. For later acquisition, an alarm counter can be read from
the display or 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)
•
Defect in the input circuit (PFC)
As soon as a power fail occurs, the device will stop to supply power and switch off the DC output.
The device can’t distinguish between intended (power switch) and unintended (blackout) dis-
connection from AC and thus will also signalize a PF alarm every time the device is switched
off. It has to be ignored in this moment.
The condition of the DC output after a PF alarm during normal operation (here: AC undervoltage)
can be set up. See
“3.4.3. Configuration via the menu“
3.3.2
Overtemperature
An overtemperature alarm (OT) can occur from an excess temperature inside the device and temporarily causes it
to switch of the power stage(s). This is usually due to the ambient temperature exceeding the specified operating
temperature range of the device. After cooling down, the device can automatically switch the DC terminal back on,
depending on the setting of parameter “DC Terminal -> State after OT alarm”. Also see section
for more
information. The alarm will remain in the display as notification and can be cleared anytime.
3.3.3
Overvoltage protection
An overvoltage alarm (OVP) will switch off the DC output and can occur if:
•
the power supply itself, as a voltage source, generates an output voltage higher than set for the overvoltage
alarm threshold (OVP, 0...110% U
Nom
) or the connected load somehow returns voltage higher than this threshold
•
the OVP threshold has been adjusted too close above the output voltage. If the device is in CC mode and if it
then experiences a negative load step, it will make the voltage rise quickly, resulting in an voltage overshoot for
a short moment which can already trigger the OVP
This function serves to warn the user of the power supply acoustically or optically that the device probably has
generated an excessive voltage which could damage the connected load application.
•
The device isn’t fitted with protection from external overvoltage
•
The changeover from operation modes CC -> CV can generate voltage overshoots
3.3.4
Overcurrent protection
An overcurrent alarm (OCP) will switch off the DC output and can occur if:
•
the output current in the DC output reaches the adjusted OCP limit.
This function serves to protect the connected load application so that this isn’t overloaded and possibly damaged
due to an excessive current.
3.3.5
Overpower protection
An overpower alarm (OPP) will switch off the DC output and can occur if:
•
the product of the output voltage and output current in the DC output reaches the adjusted OPP limit.
This function serves to protect the connected load application so that this isn’t overloaded and possibly damaged
due to an excessive power consumption.