Manual

Table Of Contents

3.3 Alarm conditions

This section only gives an overview about device alarms. What to do in case your device indicates 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) and acoustically (if activated), as

well as status via digital interface. In addition, the alarms are reported as signals on the analog interface. For later acquisition,

an alarm counter can also be shown on display or read 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)

• One or multiple power stages in the device are faulty

As soon as a power fail occurs, the device will stop to supply or sink power and switch off the DC input. In case the power fail

was an undervoltage and is gone later on, the device can continue to work as before, but this depends on a parameter in the

settings menu called DC input -> State after PF alarm. The default setting would keep the DC input switched off, but leave

the alarm in the display for notication.

Powering the device down (power switch) can’t be distinguished from a supply blackout and thus the

device will signalize a PF alarm every time it’s switched off. This can be ignored.

3.3.2 Overtemperature

An overtemperature alarm 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 specied operating temperature range of the

device. After cooling down, the device can automatically switch the DC input back on, depending on the setting of parameter

DC input -> State after OT alarm. Also see section

3.4.3.1

for more information. The alarm will remain in the display as no-

tication and can be cleared anytime.

3.3.3 Overvoltage protection

An overvoltage alarm (OVP) will switch off the DC power stage and can occur if:

• the connected voltage source provides a higher voltage to the DC input than set in the overvoltage alarm thresholds (OVP,

0...110% UNOM)

This function serves to warn the user acoustically or optically that the device probably has experienced an excessive voltage

which could damage it.

The device isn’t tted with protection from external overvoltage and could even be damaged when not

powered

3.3.4 Overcurrent protection

An overcurrent alarm (OCP) will switch off the DC power stage and can occur if:

• the current in the DC input reaches the adjusted OCP limit.

This function serves to protect the connected external source so it’s not overloaded and possibly damaged due to an exces-

sive current.

3.3.5 Overpower protection

An overpower alarm (OPP) will switch off the DC input and can occur if:

• the product of the voltage and current in the DC input reaches the adjusted OPP limit.

This function serves to protect the connected external source so it’s not overloaded and possibly damaged due to an exces-

sive power.