8
6.
MAINTENANCE AND
REPAIR
The safety relay ND1/2-D is main-
tenance-free.
In event of failure, it is possible to
change the defective device with a
new one following the steps
described below:
√
Switch off the relay and remove
the wiring from the device.
√
Take off the defective device
from the DIN-Rail.
√
Mount the new device on the
DIN-Rail.
√
Insert and fix the cables on the
new device.
7.
FAULT DIAGNOSIS
Earth Fault
(AC/DC version with
electronic fuse protection).
An electronic fuse forces the out-
put contacts to open. As soon as
the fault cause is removed, and the
rated power supply is applied, the
device is ready for new operations.
Faulty contact condition
In the event of welded contacts,
further activation is not possible
following the opening of the input
circuit.
Only one or no LED illuminates
External wiring or internal fault is
present.
Check the external wiring and
restart the safety relay.
If the fault is still present, contact
Carlo Gavazzi.
8.
WIRING HINTS FOR
OUTPUT TERMINALS
The positive power supply voltage
(for example L or 24 VDC, but not
GND) should be routed via the out-
put terminals. This will help to rec-
ognize shorts to GND or Earth.
Using R-C combination in parallel
with inductive loads (for example
coils of the external contactors)
can reduce the wearing out of the
output contacts.
