Chapter 2: Fault finding – communication
ZP3-ECU Extinguishing Control Unit Maintenance Manual
11
Device unaccepted
During initialisation on power up the panel checks all devices, noting the device
type at each address. This process can also be initiated through the Setup menu
(see the fire alarm control panel installation manual). A device Unaccepted fault
is raised when a device cannot be accepted.
Indications
• The yellow Fault LED is lit.
• The fault buzzer sounds.
• The event is shown on the display, for example:
UNACCEPTED Zone 001 Dev 001 Event 001
Second Floor, Laundry Room
• The event is printed (if a printer is configured).
Possible causes
If the unaccepted devices refer to an ECU, the possible causes are:
• Open circuit, short circuit, or missing end-of-line (EOL) resistors on field
wiring.
• Loop wiring out of specification (resistance/capacitance).
• Loose or high resistance connection on the field wiring terminals.
• An ECU that is out of calibration or is faulty.
• Interference on the loop to which the device is attached.
Corrective actions
1. Press the Accept/Panel Silence button to silence the buzzer and to
acknowledge the fault. If this fault has been raised for a number of devices on
the same loop then there may be interference on the loop. If this does not
apply then proceed to the next point.
2. Note the ECU in need of attention, and then show the analogues for the two
addresses applicable to that device on the display by using the maintenance
menu report analogue facility.
3. Check that slot 5 analogue reading is not less than 59 counts or more than
188 counts. Above or below would indicate an open circuit or shorts on the
field wiring respectively.
4. The extinguishing relay reading should also have an analogue reading in
slot 6 of between 39 and 198.
5. Take the appropriate actions to fix the problems identified in steps 3 or 4.
6. Remove power from the panel and then re-apply power. This initialises the
panel and the devices and the previously unaccepted device should now be
accepted.
