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Troubleshooting
4.5 Fault Symptoms
4.5.1 No Display
To troubleshoot no display:
Check that power is supplied.
Cycle power to the unit.
Reinitialise the drive. (See 2.2.8 Tips and Tricks.)
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4
4.5.2 Intermittent Display
Cutting out or flashing of the entire display and power
LED indicates that the power supply (SMPS) is shutting
down as a result of being overloaded. This may be due to
improper control wiring or a fault within the frequency
converter itself.
The first step is to rule out a problem in the control wiring.
To do this, disconnect all control wiring by unplugging the
control terminal blocks from the control card.
If the display stays lit, then the problem is in the control
wiring (external to the frequency converter). All control
wiring should be checked for shorts or incorrect
connections.
If the display continues to cut out, follow the procedure
for No Display as though the display were not lit at all.
4.5.3 Motor Will not Run
In the event that this symptom is detected, first verify that
the unit is properly powered up (display is lit) and that
there are no warning or alarm messages displayed. The
most common cause of this is either incorrect control logic
or an incorrectly programmed frequency converter. Such
occurrences will result in one or more of the following
status messages being displayed.
LCP Stop
The [Off] key has been pressed.
Press the [Auto on] or [Hand on] key.
Standby
This indicates that there is no start signal at terminal 18.
Ensure that a start command is present at terminal 18.
Refer to the Input Terminal Signal Test.
Unit ready
Terminal 27 is low (no signal).
Ensure that terminal 27 is logic "1". Refer to the Input
Terminal Signal Test.
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High Power Service Manual for Modular F Frame Drives
Run OK, 0 Hz
This indicates that a run command has been given to the
frequency converter but the reference (speed command) is
zero or missing.
Check the control wiring to ensure that the proper
reference signal is present at the frequency converter input
terminals and that the unit is properly programmed to
accept the signal provided. Refer to the Input Terminal
Signal Test.
Off 1 (2 or 3)
This indicates that bit #1 (or #2, or #3) in the control word
is logic "0". This will only occur when the frequency
converter is being controlled via the fieldbus.
A correct control word must be transmitted to the
frequency converter over the communication bus to
correct this.
STOP
One of the digital input terminals 18, 19, 27, 29, 32, or 33
(parameter 5-1*) is programmed for Stop Inverse and the
corresponding terminal is low (logic "0").
Ensure that the above parameters are programmed
correctly and that any digital input programmed for Stop
Inverse is high (logic "1").
Display Indication That the Unit is Functioning, but No
Output
Make sure that 14-22 Operation Mode is not set to Run With
Inverter Disabled.
If the unit is equipped with an external 24 VDC option,
check that main power is applied to the frequency
converter.
Note: In this case, the display will alternately flash Warning
8.
4.5.4 Incorrect Motor Operation
Occasionally, a fault can occur where the motor will
continue to run, but not in the correct manner. The
symptoms and causes may vary considerably. Many of the
possible problems are listed below by symptom along with
recommended procedures for determining their causes.
Wrong speed/unit will not respond to command
Possible incorrect reference (speed command).
Ensure that the unit is programmed correctly according to
the reference signal being used, and that all reference
limits are set correctly as well.
Motor speed unstable
Possible incorrect parameter settings, faulty current
feedback circuit, loss of motor (output) phase.
Check the settings of all motor parameters, including all
motor compensation settings (Slip Compensation, Load
Compensation, etc.) For Closed Loop operation, check PID
settings.
®
MG90K202 - VLT
is a registered Danfoss trademark
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