Troubleshooting; Alarm, Warning And Extended Status Word - Danfoss Native BACnet VLT HVAC Drive Operating Instructions Manual

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Troubleshooting

VLT HVAC Drive Native BACnet Operating Instructions
7 Troubleshooting
7.1 Alarm, Warning and Extended Status
Word
7.1.1 Alarm and Warning Messages
General
There is a clear distinction between alarms and warnings. In
the event of an alarm, the frequency converter will enter a
fault condition. After the cause for the alarm has been
cleared, the master must acknowledge the alarm message in
order to start operation of the frequency converter again. A
warning, on the other hand, may appear when a warning
condition arises, then disappear when conditions return to
7 7
normal without interfering with the process.
Alarm Word and Warning Word are shown on the display in
Hex format. If there is more than one warning or alarm, a
sum of all warnings or alarms will be shown. Warning Word
and Alarm Word are displayed in par. 16-90 to 16-95. For
more information on the individual alarms and warnings,
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please refer to: VLT HVAC Drive Design Guide.
Warnings
All warnings within the frequency converter are represented
by a single bit within a Warning Word. A Warning Word is
always an action parameter. Bit status FALSE [0] means no
warning, while bit status TRUE [1] means warning. Each bit
status has a corresponding text string message. In addition
to the Warning Word message the master will also be
notified via a change to bit 7 in the status word.
Alarms
Following an alarm message the frequency converter will
enter a fault condition. Only after the fault has been rectified
and the master has acknowledged the alarm message by
setting bit 3 in the Control Word, can the FC resume
operation. All alarms within the FC are represented by a
single bit within an Alarm Word. An Alarm Word is always an
action parameter. Bit status FALSE [0] means no alarm, while
bit status TRUE [1] means alarm.
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