VLT® 5000 Crane
All About VLT 5000
Crane
■
Warnings and Alarms, 7-16
Warn-
ing/Alarm
number
Display
Description
How to Handle
7
DC Link Overvolt
If the intermediate circuit voltage (DC) exceeds the
inverter overvoltage limit, the frequency converter
will trip.
Furthermore, the voltage will be stated in the
display.
The fault can be eliminated by connecting a
brake resistor (if the frequency converter has
an integral brake chopper, EB or SB)
8
DC Link
Undervolt
If the intermediate circuit voltage (DC) drops below
the inverter lower voltage limit (see table, previous
page), it will be checked whether 24 V power
supply is connected. If no 24 V power supply is
connected, the frequency converter will trip after a
given time depending on the unit. Furthermore, the
voltage will be stated in the display.
Check whether the supply voltage matcehs
the frequency converter, see Technical Data
9
Inverter Time
The electronic, thermal inverter protection reports
that the frequency converter is about to cut out
because of an overload (too high current for too
long). The counter for electronic, thermal inverter
protection gives a waring at 98% and trips at 100%,
while giving an alarm. The frequency converter
cannot be reset until the counter is below 90%..
The problem is avoided by ensuring that the
frequency converter will not be overloaded by
more than 100% for too long
10
Motor Time
According to the electronic thermal protection
(ETR), the motor is too hot. Parameter 128 allows a
choice of whether the frequency converter is to give
a warning or an alarm when the counter reaches
100%. The fault is that the motor is overloaded by
more than 100% for too long.
Check the load and that motor parameters
102-106 have been set correctly
11
Motor Thermistor
The motor is too hot and the thermistor connection
has been disconnected. Parameter 128 allows a
choice of whether the frequency converter is to
give a warning or an alarm.
Check the load and that the thermistor has
been correctly connected between terminal
53 or 54 (analogue voltage input) and terminal
50 (+ 10 Volts supply)
12
Torque Limit
The torque is higher than the value in parameter
221 (in motor operation) or the torque is higher
than the value in parameter 222 (in regenerative
operation)
Check load, acceleration and decelaration
ramps. Furthermore, check that motor
parameters 221-222 have been set correctly
13
Overcurrent
The inverter peak current limit (approx. 200% of
the rated curent) has been exceeded. The warning
will last approx. 1-2 seconds, following which the
frequency converter will trip, while giving an alarm
Turn off the frequency converter and check
whether the motor shaft can be turned
and whether the motor size mathces the
frequency converter
14 (a)
Earth Fault
There is a discharge from the output phases to
earth, either in a cable between the frequency
converter and the motor or in the motor itself
Turn off the frequency converter and remove
the earth fault
15 (a)
Switch Mode
Fault
Fault in the switch mode power supply (in/-
15 V supply)
Contact your Danfoss supplier
16 (a)
Curr. Short
circuit
There is a short-circuiting on the motor terminals or
in the motor itself
Turn off the frequency converter and remove
the short-circuit
MG.50.N4.02 - VLT is a registered Danfoss trademark
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