Danfoss VLT AQUA Design Manual page 156

8. Troubleshooting
Alarm/warning limits:
Voltage Range
Undervoltage
Voltage warning low
Voltage warning high
(w/o brake - w/brake)
Overvoltage
The voltages stated are the intermediate circuit voltage of
the frequency converter with a tolerance of ± 5 %. The
corresponding mains voltage is the intermediate circuit
voltage (DC-link) divided by 1.35
WARNING/ALARM 8, DC under voltage:
If the intermediate circuit voltage (DC) drops below the "voltage warning
low" limit (see table above), the frequency converter checks if 24 V back-
up supply is connected.
If no 24 V backup supply is connected, the frequency converter trips after
a given time depending on the unit.
To check whether the supply voltage matches the frequency converter,
see 3.2 General Specifications
WARNING/ALARM 9, Inverter overloaded:
The frequency converter is about to cut out because of an overload (too
high current for too long). The counter for electronic, thermal inverter
8
protection gives a warning at 98% and trips at 100%, while giving an
alarm. You cannot reset the frequency converter until the counter is be-
low 90%.
The fault is that the frequency converter is overloaded by more than
nominal current for too long.
WARNING/ALARM 10, Motor ETR over temperature:
According to the electronic thermal protection (ETR), the motor is too hot.
You can choose if you want the frequency converter to give a warning or
an alarm when the counter reaches 100% in par. 1-90. The fault is that
the motor is overloaded by more than nominal current for too long. Check
that the motor par. 1-24 is set correctly.
WARNING/ALARM 11, Motor thermistor over temp:
The thermistor or the thermistor connection is disconnected. You can
choose if you want the frequency converter to give a warning or an alarm
in par. 1-90. Check that the thermistor is connected correctly between
terminal 53 or 54 (analog voltage input) and terminal 50 (+ 10 Volts
supply), or between terminal 18 or 19 (digital input PNP only) and ter-
minal 50. If a KTY sensor is used, check for correct connection between
terminal 54 and 55.
WARNING/ALARM 12, Torque limit:
The torque is higher than the value in par. 4-16 (in motor operation) or
the torque is higher than the value in par. 4-17 (in regenerative opera-
tion).
WARNING/ALARM 13, Over Current:
The inverter peak current limit (approx. 200% of the rated current) is
exceeded. The warning will last approx. 8-12 sec., then the frequency
converter trips and issues an alarm. Turn off the frequency converter and
check if the motor shaft can be turned and if the motor size matches the
frequency converter.
ALARM 14, Earth fault:
There is a discharge from the output phases to earth, either in the cable
between the frequency converter and the motor or in the motor itself.
Turn off the frequency converter and remove the earth fault.
156
3 x 200-240 V AC 3 x 380-500 V
AC
[VDC] [VDC]
185 373
205 410
390/405 810/840
410 855
.
MG.20.N3.02 - VLT
ALARM 15, In-complete hardware:
A fitted option is not handled by the present control board (hardware or
software).
ALARM 16, Short-circuit:
There is short-circuiting in the motor or on the motor terminals.
Turn off the frequency converter and remove the short-circuit.
WARNING/ALARM 17, Control word timeout:
There is no communication to the frequency converter.
The warning will only be active when par. 8-04 is NOT set to
If par. 8-04 is set to Stop and Trip
converter ramps down to zero speed, while giving an alarm.
Control Word Timeout Time
Par. 8-03
WARNING 23, Internal fans:
External fans have failed due to defect hardware or fans not mounted.
WARNING 24, External fan fault:
The fan warning function is an extra protection function that checks if the
fan is running / mounted. The fan warning can be disabled in
tor
, par. 14-53, [0] Disabled.
WARNING 25, Brake resistor short-circuited:
The brake resistor is monitored during operation. If it short-circuits, the
brake function is disconnected and the warning appears. The frequency
converter still works, but without the brake function. Turn off the fre-
quency converter and replace the brake resistor (see par. 2-15
Check ).
ALARM/WARNING 26, Brake resistor power limit:
The power transmitted to the brake resistor is calculated as a percentage,
as a mean value over the last 120 s, on the basis of the resistance value
of the brake resistor (par. 2-11) and the intermediate circuit voltage. The
warning is active when the dissipated braking power is higher than 90%.
Trip
If [2] has been selected in par. 2-13, the frequency converter cuts
out and issues this alarm, when the dissipated braking power is higher
than 100%.
WARNING/ALARM 27, Brake chopper fault:
The brake transistor is monitored during operation and if it short-circuits,
the brake function disconnects and the warning comes up. The frequency
converter is still able to run, but since the brake transistor has short-
circuited, substantial power is transmitted to the brake resistor, even if it
is inactive.
Turn off the frequency converter and remove the brake resistor.
Warning: There is a risk of substantial power being
transmitted to the brake resistor if the brake transistor
is short-circuited.
ALARM/WARNING 28, Brake check failed:
Brake resistor fault: the brake resistor is not connected/working.
WARNING/ALARM 29, Drive over temperature:
If the enclosure isIP00, IP20/Nema1 or IP21/TYPE 1, the cut-out tem-
perature of the heat-sink is 95
be reset, until the temperature of the heatsink is below 70
The fault could be:
- Ambient temperature too high
- Too long motor cable
®
is a registered Danfoss trademark
®
VLT AQUA Drive Design Guide
OFF .
, a warning appears and the frequency
could possibly be increased.
Fan Moni-
Brake
o o
C +5 C. The temperature fault cannot
o
C.