Man-1078_Sigma_CP_22
Page 19 of 24
Once the required configuration options have been set, the Write enable switch
must
be returned to its
normal position to the right. The General fault indicator will remain lit if the Write enable switch is not turned
off.
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18. Watchdog reset switch
If for any reason the microprocessor in the control panel fails to carry out its operation correctly it will
attempt to restart itself. This process is called a “watchdog” and the control panel must record and indicate
these events.
If a watchdog event occurs, the control panel will show the FAULT and SYSTEM FAULT LEDs on the front
panel, the CPU fault LED inside the panel.
This fault can only be cleared by pressing the WATCHDOG RESET button on the PCB inside the control
panel. The control panel buzzer can not be silenced and will continue to sound until the watchdog activation
is reset.
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19. Processor reset switch
Once started, the microprocessor controlling the panel should continue to run continuously without
interruption. If the microprocessor fails to run correctly it can be reset by pressing the PROCESSOR RESET
button on the PCB inside the control panel.
This should not normally be necessary but should be done as a matter of course if the system is behaving
abnormally. The system should resume normal operation within a couple of seconds of pressing the
processor reset button.
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20. Internal indications – troubleshooting
To assist in identifying fault conditions which are not detailed on the front of the control panel, a number of
internal indicators are visible with the front cover removed as follows:
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20.1 Mains fail
Indicates that the 230V AC supply is not present and the system is running on standby batteries.
If there is not a power cut, check the panels mains fuse.
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20.2 Batt fail
Indicates that the standby battery has become disconnected or that the charging circuit of the control panel
has a high resistance or has failed. Check that both batteries are connected and linked together. Test
battery. Disconnect battery and ensure that 28 Volts can be measured on battery charger leads.
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20.3 CPU fault
Indicates that the central processor unit has failed to correctly execute code and has been re-started by the
system watchdog. The watchdog reset switch must be pressed to clear the CPU fault condition.
Press watchdog reset. If system does not return to normal then the panel is probably damaged and needs
the circuit board replacing. (See maintenance section).
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20.4 Aux 24V fault
The Aux 24V and R0V terminals provide a 500 milliamp, 24V DC power supply for power fire alarm ancillary
equipment. This LED indicates that fuse protecting the R0V output has operated and the rating of this output
has been exceeded. The fuse is a self resetting type and the supply will resume when the fault condition is
removed.
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20.5 Batt low
Illuminates when the system is running on batteries and the battery voltage is lower than 21V +/-2% (the
minimum battery voltage).
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20.6 Earth fault
Indicates that part of the system wiring is connected to earth. Remove all system wiring and re-connect
cables one at a time until the earth fault returns. This will indicate which cable the earth fault is present on.
Summary of Contents for Sigma CP K Series
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