Testing; Maintenance And Repair - ABB saco 64D4 User Manual

Testing

Maintenance
and repair
40
The alarm annunciator unit is provided with
an automatic self-supervision system which
monitors the internal system voltages as well as
the function of the microprocessor and the logi-
cal circuits.
If an internal fault situation is detected, the con-
tact of the output relay of the self-supervision
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 in-
clude no parts or components, which are sub-
ject to an abnormal physical or electrical wear
under normal operating conditions.
If the environmental conditions at the operat-
ing site differ from those specified, as to ambi-
ent 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plug-in modules are withdrawn from the case.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 test push-button on the module SWDM
3A1, located to the left in the rack (if present),
continuously for more than one second. Then
all LED indicators, except the FAULT indica-
tor, on the front panel are switched on. If the
push-button is depressed for more than 15 sec-
onds, 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
repaired by a competent specialist in an author-
ized repair shop.
Generally a fault can be eliminated by chang-
ing a plug-in module, please refer to the spare
part list. When a new alarm module SWPM
3A1B is inserted, the programmed parameter
memory of the old alarm module can be plugged
to the new module. Thus the new alarm mod-
ule is ready to work with the same operating
values as the old one without being separately
programmed. 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