Danfoss VLT series, Руководство по обслуживанию

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3-1
VLT is a registered Danfoss trademark
SECTION 3
TROUBLESHOOTING
TROUBLESHOOTING TIPS
Before attempting to repair a drive, here are some tips to follow
to make the job easier and possibly prevent unnecessary
damage to functional components.
1. Note all warnings concerning voltages present in
the drive. Always verify the presence of AC input
voltage and DC bus voltage before working on
the unit. Some points in the drive are referenced
to the negative DC bus and are at bus potential
even though it may appear on diagrams to be a
neutral reference.
Remember that voltage may be present for
as long as 40 minutes on E-frame size
drives or 20 minutes on D-frame size drives
after removing power from the unit.
2. Never apply power to a unit that is suspected of
being faulty. Many faulty components within the
drive can cause damage to other components
when power is applied. Always perform the
procedure for testing the unit after repair as
described in Section 5,
Test Procedures .
3. Never attempt to defeat any fault protection
circuitry within the drive. That will result in
unnecessary component damage and may
cause personal injury.
4. Always use factory approved replacement parts.
The drive has been designed to operate within
certain specifications. Incorrect parts may affect
tolerances and result in further damage to the
unit.
5. Read the instruction and service manuals. A
thorough understanding of the unit is the best
approach. If ever in doubt, consult the factory or
authorized repair center for assistance.
Exterior Fault Troubleshooting
There may be slight differences of servicing a drive that has
been operational for some extended period of time compared
to a new installation. With good troubleshooting techniques,
however, it is not safe to make many assumptions. To assume
a motor is wired properly because the drive has been in service
for some time may overlook loose connections, improper
programming, or added equipment, for example. It is best to
develop a detailed approach, beginning with a physical
inspection of the system. See Table 3-1,
Visual Inspection , for
items to examine.
Fault Symptom Troubleshooting
This troubleshooting section is divided into sections based on
the symptom being experienced. To start Table 3-1 provides a
visual inspection check list. Many times the root cause of the
problem may be due to the way the drive has been installed or
wired. The check list provides guidance through a variety of
items to inspect during any drive service process.
Next, symptoms are approached as the technician most
commonly discovers them: reading an unrecognized drive
display, problems with motor operation, or a warning or alarm
displayed by the drive. Remember, the drive processor monitors
inputs and outputs as well as internal drive functions, so an
alarm or warning does not necessary indicate a problem within
the drive itself.
Each incident has further descriptions on how to troubleshoot
that particular symptom. When necessary, further referrals are
made to other parts of the manual for additional procedures.
Section 4,
Drive and Motor Applications , presents detailed
discussions on areas of drive and system troubleshooting that
an experienced repair technician should understand for effective
analysis.
Finally, a list of tests called After Repair Tests is provided. These
tests should always be performed when first starting a drive,
when approaching a drive that is suspected of being faulty, or
anytime following a repair to the drive.
3.0 Fault Symptoms
3.1 Display
3.1.1 No Display
3.1.2 Intermittent Display
3.1.3 Display Line 2 Flashing
3.1.4 WRONG Displayed
3.2 Motor
3.2.1 Motor Will Not Run
3.2.2 Incorrect Motor Operation
3.3 Warnings and Alarms
3.4 After Repair Tests