Torque Limit; Over Current; Earth Fault; Short Circuit - Danfoss VLT AutomationDrive FC 300 Design Manual

FC 300 Design Guide
Check that the thermistor is connected correctly
between terminal 53 or 54 (analog voltage input)
and terminal 50 (+ 10 V supply), or between ter-
minal 18 or 19 (digital input PNP only) and termi-
nal 50. If aKTY sensoris 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 operation).
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 con-
verter trips and issues an alarm. Turn off the fre-
quency converter and check if the motor shaft can
be turned and if the motor size matches the fre-
quency converter.
If extended mechanical brake control is selected,
trip can be reset externally.
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.
ALARM 15
In-complete hardware:
A fitted option is not handled by the present con-
trol 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 con-
verter.
The warning will only be active when par. 8-04 is
NOT set to OFF.
If par. 8-04 is set to Stop and Trip, a warning ap-
pears and the frequency converter ramps down
until it trips, while giving an alarm.
par. 8-03 Control word Timeout Time could pos-
sibly be increased.
154
Troubleshooting
WARNING 23

Internal fan fault:

The fan warning function is an extra protection
function that checks if the fan is running / moun-
ted. The fan warning can be disabled in Fan Mon-
itor, par. 14-53, (set to [0] Disabled).
WARNING 24

External fan fault:

The fan warning function is an extra protection
function that checks if the fan is running / moun-
ted. The fan warning can be disabled in Fan Mon-
itor, par. 14-53, (set to [0] Disabled).
WARNING 25

Brake resistor short-circuited:

The brake resistor is monitored during operation.
If it short-circuits, the brake function is discon-
nected and the warning appears. The frequency
converter still works, but without the brake func-
tion. Turn off the frequency converter and replace
the brake resistor (see par. 2-15 Brake Check).
ALARM/WARNING 26
Brake resistor power limit:
The power transmitted to the brake resistor is cal-
culated 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 intermedi-
ate circuit voltage. The warning is active when the
dissipated braking power is higher than 90%. If
Trip [2] has been selected in par. 2-13, the fre-
quency converter cuts out and issues this alarm,
when the dissipated braking power is higher than
100%.
WARNING 27
Brake chopper fault:
The brake transistor is monitored during opera-
tion and if it short-circuits, the brake function dis-
connects and the warning comes up. The frequen-
cy 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 in-
active.
Turn off the frequency converter and remove the
brake resistor.
MG.33.B8.02 - VLT ® is a registered Danfoss trademark
Warning: There is a risk of substantial
power being transmitted to the brake
resistor if the brake transistor is short-
circuited.