HTC 650 HDX Manual page 30

Electronic error codes cont.
Error code
SCF
tnF
OLF
OSF
USF
Cause
SCF = Short circuit on motor side.
Due to a short circuit either in the
motor or in the motor cable. May also
be an earth fault.
tnF = Autotuning fault.
May arise if the motor has replaced a
defective motor. The motor is outside
the norms for what a converter can
handle. Could also arise if the motor
is defective.
OLF = Overload motor.
Tripped motor protection. Arises
following long-term overload of the
motor. The motor protection in the
converter trips to protect the motor.
OSF = Overvoltage.
Mains voltage too high or
interference in the mains. May arise
if large motors/machines are started
or shut down in the vicinity. May arise
from non CE- marked equipment.
USF = Undervoltage
Mains voltage too low. Occurs when
the mains has too many users.
Temporary loss of voltage. Long and/
or weak cables may cause this error.

Action
Check the cabling and test the
insulation in the motor if necessary.
Test by loosening the motor cable
and starting the frequency converter
to see if the error code arises. If it
does, the error is in the frequency
converter. If not, the cable or the
motor is probably defective.
Check the motor. Exchange the
motor for an original motor.
Reduce the speed of the grinder.
The grinder runs too robustly. It takes
around  minutes before the grinder
can be started again. The motor
protection must cool down.
Measure the feed voltage. Change
the terminal. Max feed voltage is
240V + 10%.
Change terminal or remove users
from the mains. (Welds and such
cause these errors). Replace cable.