Danfoss Compressor Drives Troubleshooting Check List
Compressor Drives
Troubleshooting Check List
CDS 302/CDS 303
http://cc.danfoss.com
Check List
Content
Introduction ......................................................................................................................................... 4
For Your Safety ..................................................................................................................................... 5
Diagnostics...........................................................................................................................................6
Initial Trouble Shooting (visual inspection of the installation) ....................................................... 7
Input power wiring ................................................................................................................................................................................... 7
Output to motor ........................................................................................................................................................................................ 7
Grounding .................................................................................................................................................................................................... 7
Control wiring ............................................................................................................................................................................................. 7
Programming .............................................................................................................................................................................................. 7
Compressor Motor .................................................................................................................................................................................... 7
Cable routing .............................................................................................................................................................................................. 7
Peripheral equipment (sensors, contactors, etc) ............................................................................................................................7
Trip on over Temperature ....................................................................................................................................................................... 7
Drive interior ............................................................................................................................................................................................... 7
EMC Precautions ........................................................................................................................................................................................ 7
Vibration ....................................................................................................................................................................................................... 7
Environmental conditions ...................................................................................................................................................................... 7
Proper clearance ........................................................................................................................................................................................ 7
Trouble shooting ................................................................................................................................8
Fault Symptoms - Display of the drive .............................................................................................................................................. 8
No display (blank display) ...................................................................................................................................................................... 8
Intermittent display .................................................................................................................................................................................. 8
Fault Symptoms in the compressor (motor) ....................................................................................................................................9
Common drives and motor problems ..............................................................................................11
Control logic problems ..........................................................................................................................................................................11
Programming problems ........................................................................................................................................................................11
IGBT, Motor or load problems ............................................................................................................................................................12
Procedure to conduct the dynamic test to check the IGBT .....................................................................................................12
Faults in the drive ....................................................................................................................................................................................12
EMC - Electro Magnetic Compatibility .............................................................................................................................................13
Static test procedures .......................................................................................................................14
Rectier test (static) ................................................................................................................................................................................14
IGBT static test ..........................................................................................................................................................................................15
3FRCC.PC.036.A2.02
Check List
Introduction
Many frequency converters that are sent back
to Danfoss every year for factory analysis
are diagnosed with No Fault Found (NFF).
Establishing whether a frequency converter is
faulty or not prior returning it to the factory can
increase the uptime of the compressor solution,
reduce the unnecessary use of resources and
limit the number of NFF.
The purpose of this check list is to facilitate
users, eld technicians, engineers and service
personnel working with Danfoss frequency
converters to identify faults and perform a
rst diagnosis on the drive before sending it to
inspection and analysis.
PERFORM THE FOLLOWING FAULT DIAGNOSIS
BEFORE RETURNING A FREQUENCY CONVERTER FOR
FACTORY INSPECTION.
CHECK ALL POSSIBILITIES.
IN CASE OF DOUBT, PLEASE SEEK DANFOSS SUPPORT.
4 FRCC.PC.036.A2.02
Check List
For Your Safety
Figure 1: Drive must be
turned OFF for 20min before
repair can start
Frequency Converters (FC) contain dangerous
voltages when connected to the line voltage.
Only a competent technician should carry out
the service.
Some instructions should be compulsorily
followed to ensure safety while working with the
FC.
• Do not touch electrical parts of the FC when the
AC line is connected.
• Frequency converters contain DC-link capacitors
that can remain charged even when the
frequency converter is not powered. To avoid
electrical hazards, disconnect AC mains, any
permanent magnet type motors, and any
remote DC-link power supplies, including
battery backups, UPS and DC-link connections
to other frequency converters.
• Wait for at least 20 minutes before touching any
of the components.
• When repair or inspection is done, the AC line
must be disconnected.
• The STOP key on the control panel does not
disconnect the AC line.
• During operation and programming of the
parameters, the motor may start without
warning. So you have to activate the STOP key
when changing data.
5FRCC.PC.036.A2.02
Check List
Diagnostics
WARNINGS and ALARM
Fault detection via LCP: messages are displayed
when the frequency converter fault circuit
detects a faulty condition or an unresolved fault.
A warning light ashing display indicates
potential problems.
There are two levels of alarms; Reset Alarms and
Trip-lock Alarms.
Alarm Log Check the content of the alarm log.
5 latest alarms are available through the “Alarm
Log” button key on the LCP.
Check the alarm code and refer to the
troubleshooting session of the Operating
Instructions VLT® CDS 302 and CDS 303 on page
135. It contains guidance for the complete list
of alarms and warnings.
Figure 2: WARNINGS
and ALARM messages
are displayed when the
frequency converter fault
detects a faulty condition
a) In case of reset alarm: you can stop and then
start the unit.
b) In case of trip-lock alarm, you have to
disconnect the mains, wait for dark display,
then stop and start.
If the troubleshooting suggested does not
resolve the problem, please contact Danfoss for
support.
Do not exchange the drive before contacting
Danfoss support.
6 FRCC.PC.036.A2.02
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