Maintenance and fault tracing7SV512
V1
107C53000---G1176---C91
7.2 Replacing the clock module
Ifthe device is equipped with theclock option (mod-
el 7SV512K---KKKK1---KK, refer Section 2.3 Ordering
data), the device annunciations are stored in NV---
RAMs. The clock module contains also the back-up
battery so that the annunciations are retained even
with a longer failure of the d.c. supply voltage.
The clock module should be replaced at the latest
after 10 years of operation.
Recommended clock module:
--- DALLAS
DS 1386 --- 32 K
RAMified TIMEKEEPER
The module is located on the CPU cart. The com-
plete draw-out module must be removed from the
housing in order to replace the clock module.
The procedure when replacing the clock module is
described below.
--- Prepare area ofwork: provide conductive surface
for the basic module.
--- Open housing cover.
--- Read out device annunciations, i.e. all addresses
which commence with 5 (5000 onwards). This is
carried out most convenient using the front oper-
ating interface and a personal computer with the
DIGSIr protection data processing program; the
information is thus stored in the PC.
Note:All configuration data and settings of the de-
vice are stored in EEPROMs protected against
switching offofthe power supply.They arestored
independent of the back-up battery. They are,
therefore, neither lost when the battery is re-
placed nor when the device is operated without a
battery.
--- Prepare the battery as in Figure 7.1:
Hazardous voltages can be present in
the device even after disconnection of
the supply voltage orafter removal ofthe
modules from the housing (storage ca-
pacitors)!
!
Warning
--- Loosen the draw-out module using the pulling
aids provided at the top and bottom. (Figure 7.3).
Electrostatic discharges via the compo-
nent connections, the PCB tracks or the
connecting pins of the modules must be
avoided under all circumstances by pre-
viously touching an earthed metal sur-
face.
!
Caution!
--- Pulloutthemodule and place ontotheconductive
surface.
--- Get access to the CPU board.
--- Pull out used clock module from the socket ac-
cording to Figure 7.1; do not place on the con-
ductive surface!
--- Insert the prepared new clock module into the
socket; observe correct mounting position.
--- Remount PCB board to the draw-out module.
--- Insert draw-out module into the housing; ensure
that the releasing lever is pushed fully to the right
before the module is pressed in.
--- Firmly push in the module using the releasing le-
ver. (Figure 7.3).
The discharged battery contains Lithium.
It must onlybedisposed off in line with the
applicable regulations!
Do not reverse polarities! Do not re-
charge! Do not throw into fire! Danger
of explosion!
!
Warning
--- Providedthe internal system clockis notautomat-
ically synchronized via the LSA interface, it can
now be set or synchronized as described in Sec-
tion 6.5.1
--- Close housing cover.
The replacement of the clock module has thus been
completed.
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