14
LH 5946 / 130910 / 363
maintenance and repairs
- The device contains no parts that require maintenance.
- In case of failure, do not open the device but send it to manufacturer
for repair.
Failure:
The unit enables the safety outputs while the motor is still turning (LED
„OUT“ lights green).
Solution:
Reduce setting of U
an
if necessary to minimum. If the outputs are still
enabled a wiring problem on the measuring wires could be the reason
(short circuit on terminals L2/L3 to L1) or the motor generates only a very
low remanence voltage. Please check connection of measuring inputs to
motor winding according to the connection examples.
Failure:
The output contacts are enabled to early (motor has not finally stopped):
Solution:
Adjust setting value U
an
to lower level. Additionally the delay time ts could
be increased.
Failure:
Output contacts remain disabled while the motor is already on standstill
Solution:
Observe status of indicator LEDs:
1. LED „UH“ lights green?
If
yes
, go to 2.
If
no
, U
H
has undervoltage or the unit has an internal device failure.
(Internal failures can occur in the case of undervoltage, welded safety
output contacts or seldom because of interference)
⇒
switch supply voltage off and on. If the failure still exists in spite
of correct auxiliary supply UH the unit could be defective and
has to be sent to manufacturer for test or repair.
2. LED „ERR“ (red) flashes with code 1?
If
no
, go to 3.
If
yes
, the unit has detected undervoltage
⇒
Apply correct auxiliary voltage
3. LED „OUT“ flashes green?
If
no
, go to 4.
If
yes
, standstill is detected, but the time ts till enabling of the outputs is
not elapsed.
⇒
wait till time ts is finished.
If after 6 s the outputs are not enabled, the measuring input L1-L2-L3
receives intermittent voltage peaks that are higher then U
an
.
This should normally be indicated by intermittent yellow flashes on the
LED).
⇒
Adjust U
an
to a higher value, clear interference on measuring
wires (use screened cables).
4. LED „OUT“ lights yellow?
If
yes
, the voltage on the measuring input is higher then the adjusted
value U
an
; go to 5.
If
no
, LED is off
Standstill is detected (voltage on measuring input is <U
an
) but the outputs
are not enabled because
a)
Feedback circuit X1-X2 is not closed or
b)
a simultaneity failure occurred (see failure monitoring) or
c)
a previous failure ( broken wire / offset, feedback circuit) is still
stored (terminals x2-x3 are not linked.
The type of failure is indicated by flash code on the red LED „ERR“:
a) flash code 4 (feedback circuit not closed)
b) flash code 5 (simultaneity fault of the measuring signals on L2 L3)
c) code 2, 3 or 4 depending on priority and failure.
⇒
- close feedback circuit
- Bridge terminals X2-X3 (manual reset)
If now still the simultaneity failure (flash code 5 on LED „ERR“) is
indicated it can be reset by switching the auxiliary supply off and
on. The reset also takes place, when both input signals rise above
Uan e.g. when starting the motor. If the simultaneity failure remains
active after start of the motor (e.g. because of short circuit between
L2-L1 or L3-L1) the wiring of the measuring circuit has to be checked
according to the connection example.
If the simultaneity failure occurs often e. g. on slow decease of the
motor speed, the problem can be solved by increasing the tripping
value U
an
or/and by making a single phase instead of a 3-phase
connection of the measuring circuit to the motor.
5. LED „OUT“ lights yellow while the motor is on standstill
If the yellow LED „OUT“ is on this indicates that the measuring inputs
still receive an input signal higher then the adjusted value U
an
Observe in addition the LED „ERR“:
a) if it stays off after a time of 8 s the problem could be a interference
or residual voltage (induced AC voltage) on the measuring inputs
⇒
Increase the setting of U
an
If this shows no result, or if an increase is not wished, the
interference to the measuring lines must be reduced e.g. by
screening, shortening or separating the wires, Test: Disconnect
motor and short circuit terminals L1-L2-L3 on the unit, the yellow
LED must change to green or green flashing.
b) if the red LED flashes code 2 the unit has detected broken wire or
DC voltage offset between the measuring inputs L1 and L2 (or
between L1 and L2 and L1 and L3).
c) if the red LED flashes code 3 the unit has detected broken wire or
DC voltage offset on measuring input L3
In the 2 last cases the wiring between LH 5946 terminals L1-L2-L3 and
the motor terminals has to be checked on interruption. Possibly the
interruption comes from disregarding the operating remarks for motors
with switchable windings (see remarks).
If failures by interruption of the input circuits can be excluded the failure can
result from a DC voltage offset > Uan. This can come from motor controllers
like inverters or DC brakes that are not completely switched off and supply
a DC-voltage to the measuring circuit (check with Voltmeter).
If the DC content is only minor, the failure can be removed by increasing
the setting value Uan The yellow LED „OUT“ must change to green or
green flashing. If not the motor controllers must be switched off in a way
that standstill can be detected correctly.
Failure:
While motor is on operation a failure is indicated.
If the LED „UH“ lights red, an internal failure occurred.
Solution:
Switch auxiliary supply off and on again (see 1.)
If the LED „ERR“ indicates a failure the flash code shows the type of fault
and how to remove it. Flash code 2 or 3 are normal during operation of
DC motors. If the terminals X2-X3 are bridged, The failure is reset auto-
matically at standstill and the output relays are enabled. The same is valid
for operation with electronic controllers, if these produce a DC voltage e.g.
during braking of a DC-brake.
Troubleshooting
Troubleshooting
