Chapter 3: Fault finding – ECU faults
ZP3-ECU Extinguishing Control Unit Maintenance Manual
19
Extinguishant actuator faults
Indications
• The Detonator Fault LED on the ECU main board illuminates (see Figure 1 on
• The Fault LED on the ECU front panel illuminates.
• A GNFLT fault message is displayed on the ZP3 Fire Alarm Control Panel
and the panel buzzer sounds. The Fault LED on the ZP3 Fire Alarm Control
Panel also illuminates.
GNFLT Zone 001 Dev 5001 Event 002
Possible causes
• The EOL resistor across the actuator switch is not inserted or the circuit is an
open circuit.
• The detonator fuse on the ECU PCB is missing or blown.
Corrective actions
1. Press the Accept/Panel Silence button to silence the buzzer and to
acknowledge the fault.
2. Inspect the EOL resistor. If missing, insert one between terminals 7 and 8 of
TB3 on the ECU display board.
3. Inspect detonator fuse, replace fuse if it is missing or blown.
4. Check continuity of the monitored circuit.
5. Reset the panel.
