MD Helicopters MD Explorer - Fault Isolation; Fire Extinguisher System Troubleshooting

CSP−900RMM−2MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 101
Revision 4
26-20-20
FIRE EXTINGUISHER SYSTEM
FAULT ISOLATION
1. Fire Extinguisher System
Troubleshooting
(Ref. Figure 101)
The following troubleshooting procedures are a
brief summary of fire extinguisher system
faults which may be encountered (Ref.
Table 101).
Troubleshooting tables should be used with
system schematics, electrical wiring diagrams,
serviceability checks and other detailed
procedures in this and other chapters of the
manual.
Comprehensive wiring diagrams are available
in the Rotorcraft Maintenance Manual
CSP-900RMM-3.
Table 101. Troubleshooting
Fault Probable Cause Corrective Action Ref. Section
TANK PRESS LO displayed
on IIDS with fire bottle
gauge indicating within
acceptable limits.
Faulty wiring. Test and repair wiring (1). 98−00−00
Faulty gauge. Replace fire bottle. 26−20−20
Faulty IIDS. Replace IIDS. 95−30−00
Fire bottle gauge indicates
below acceptable pressure
limits.
Container leaking. Replace fire bottle. 26−20−20
Faulty gauge. Replace fire bottle. 26−20−20
Fire bottle gauge indicates
below 250 psig (1724 kPa),
TANK PRESS LO not
displayed on IIDS.
Faulty wiring. Test and repair wiring (1). 98−00−00
Faulty gauge. Replace fire bottle. 26−20−20
Faulty IIDS. Replace IIDS. 95−30−00
Cartridge did not discharge
extinguishing agent.
FUEL SHUTOFF valve
switch not positioned to
OFF.
Check FUEL SHUTOFF valve
position.
96−00−00
Circuit breaker FIRE HRD
not set.
Set or reset circuit breaker 96−00−00
Faulty FIRE HRD circuit
breaker.
Replace circuit breaker. 96−00−00
Faulty wiring. Test and repair wiring (1). 98−00−00
Faulty PRI/ALT select
switch.
Replace switch. 96−00−00
Faulty FUEL SHUTOFF
valve switch.
Replace switch. 96−00−00
Faulty discharge cartridge. Replace discharge cartridge. 26−20−20
ACFTFALT=12, IIDS sensor
fault for TANK PRESS LO.
Faulty wiring. Test and repair wiring (1). 98−00−00
Faulty gauge. Replace fire bottle. 26−20−00
Faulty IIDS. Replace IIDS. 95−30−00
NOTES:
(1) Disconnect electrical connectors from discharge cartridge, and install shunt plug covers before trouble
shooting wiring faults.