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Testing
Maintenance
and repair
44
The alarm annunciator unit is provided with an
automatic self-supervision system which moni-
tors the internal system voltages as well as the
function of the microprocessor and the logical
circuits.
If an internal fault situation is detected, the
contact of the output relay of the self-supervi-
sion system drops off and the FAULT LED is
switched on.
When the annunciator unit is operating under
normal service conditions as specified in the
section "Technical data", the annunciator unit
is practically maintenance free. The modules
include no parts or components, which are
subject to an abnormal physical or electrical
wear under normal operating conditions.
If the environmental conditions at the operating
site differ from those specified, as to ambient
temperature, humidity or if the atmosphere
around the annunciator unit holds chemically
active gases or dust, the modules ought to be
visually inspected in association with the sec-
ondary testing being performed or whenever the
plug-in modules are withdrawn from the case.
At the visual inspection the following things
should be noted:
- possible mechanical damage of the mounting
case, mounting brackets or frame, plastic lid or
its rubber gasket, plug-in units or their con-
nection sockets
- signs of oxidation on the PCBs, component
legs and cups, screws and other metallic parts
- traces of dust and dirt accumulating inside the
plastic lid, on the PCB or inside the case.
Check the condition of the rubber gasket of
the lid.
The LED indicators can be tested by pressing the
acknowledge/reset push-button continuously for
more than one second. Then all LED indicators,
except the FAULT indicator, on the front panel
are switched on together with all the segments of
the digital display. If the push-button is depressed
for more than 15 seconds, the FAULT indicator
also turns on and the output relay of the self
supervision system drops off.
It is recommended that the function of the field
contact circuits are tested by performing pri-
mary tests to the field contacts.
If the annunciator unit fails in operation or if the
operating values differ from those specified, the
annunciator unit should be checked and re-
paired by a competent specialist in an author-
ized repair shop.
Generally a fault can be eliminated by changing
a plug-in module, please refer to the spare part
list. When a new alarm module SWPA 3A1 is
inserted, the programmed parameter memory
of the old alarm module can be plugged to the
new module. Thus the new alarm module is
ready to work with the same operating values as
the old one without being separately pro-
grammed. The parameter memory is marked
D17.
IMPORTANT!
When the memory circuit is plugged in, the slot
on the circuit should point towards the front
panel of the module. In this way possible dam-
age of the memory circuit can be avoided. Please
always use EDS protection when handling the
electronic circuit
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