Danfoss VLT Inverter Scroll CDS 801 Operating Instructions Manual page 48

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Fault Conditions, Messages ... VLT Inverter Scroll CDS 801 Operating Instructions
This alarm indicated that the system has encountered a
loss of charge. If this alarm is subsequently reported 10
times the drive goes into a trip lock condition.
Bit 14, Alarm - Defrosting Timeout
If the system has operated in system Defrost mode for
more than 1800 s, the system stops. The drive enters a trip
lock condition.
Bit 15, Alarm - Restart too frequently
The amount of times that the compressor speed has been
0 Hz within 600 s is counted. When the counter reaches
the count of 6, the drive enters a trip lock condition.
Bit 31, Alarm – Internal Error
The drive has encountered an internal error, e.g. missing
communication between the microprocessors. The drive
goes immediately into a trip lock condition. It is likely that
the drive will not recover from this condition!
NOTE
7 7
When operation the system in an open loop configuration
(by means sending a speed reference to the Performer VSD
application controller) the temperature controller in the
Modbus Master (thermostat) controller should feature an
Anti-Wind-up function that is activated whenever the drive
is in derating mode! In derating mode, the system cannot
satisfy the requested compressor speed and the integrator
of the PID-controller should be stopped until the system
has returned to normal operation.
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46 MG10V402 - VLT is a registered Danfoss trademark