Inspect For
Description
Vibration
Look for any unusual amount of vibration around the adjustable frequency drive. The unit should be
mounted solidly or the use of shock mounts employed.
Table 4.1 Visual Inspection
4.5 Fault Symptoms
4.5.1 No Display
The LCP display provides two display indications. One with
the backlit LCD alphanumeric display. The other is three
LED indicator lights near the bottom of the LCP. If the
green power-on LED is illuminated but the backlit display
is dark, it indicates that the LCP is defective and must be
replaced.
On
Warn.
Alarm
130BP044.10
Figure 4.1
If neither indication is available, then the source of the
problem is elsewhere. Proceed to
to carry out further troubleshooting steps.
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. Improper control
wiring, overload of the 24 V output, or a fault within the
adjustable frequency drive itself could cause this overload.
The first step is to rule out a problem in the control wiring.
Disconnect all control wiring from the control terminal
blocks from the control card. If the display stays lit, then
the problem is in the control wiring (external to the
adjustable frequency drive). Check all control wiring 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
When this symptom occurs, 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 is either incorrect control logic or an incorrectly
programmed adjustable frequency drive. Such occurrences
result in one or more of the following status messages
being displayed.
LCP Stop
Action: 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.
Action: Ensure that a start command is present at terminal
18. Refer to
chapter 6.4.14 Input Terminal Signal Tests
.
Unit ready
Terminal 27 is low (no signal).
Action: Ensure that terminal 27 is logic “1”. Refer to
chapter 6.4.14 Input Terminal Signal Tests
.
Run OK, 0 Hz
This indicates that a run command has been given to the
adjustable frequency drive but the reference (speed
command) is zero or missing.
Check the control wiring for the proper reference signal at
the adjustable frequency drive input terminals and to
ensure that the unit is properly programmed to accept the
signal provided. Refer to
Off 1 (2 or 3)
This display indicates that bit #1 (or #2, or #3) in the
control word is logic “0” and only occurs when the
adjustable frequency drive is being controlled via the serial
communication bus.
A correct control word must be transmitted to the
adjustable frequency drive over the communication bus.
STOP
One of the digital input terminals 18, 19, 27, 29, 32, or 33
(parameter group
5–1* Digital Inputs
) is programmed for
[6]
Stop Inverse
and the corresponding terminal is low
(logic “0”).
Troubleshooting
Service Manual
48
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
MG94A222
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