MD Helicopters MD Explorer - Fault Isolation; Air-Conditioning System Troubleshooting; Early Config

CSP−900RMM−2MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 101
Revision 34
21-50-00
AIR−CONDITIONING SYSTEM
FAULT ISOLATION
1. Air−Conditioning System Troubleshooting
(Ref. Figure 101 thru Figure 103)
The troubleshooting procedures in Table 101
are air-conditioning system faults which
possibly can occur.
Troubleshooting tables are used with system
schematics, electrical wiring diagrams,
serviceable checks, and also refer to other
procedures in this manual.
Wiring diagrams are available in the Rotor
craft Maintenance Manual CSP-900RMM-3
(ref. Section 98-40-00).
Table 101. Air−Conditioning System Troubleshooting
Fault Probable Cause Corrective Action Ref. Section
Air Condition does not
operate when the COOL
LOW or COOL HI selection
is made on the Utility Control
Panel during normal engine
operation.
(See Note 1)
Circuit breaker COMP
(CB17) open.
Replace or reset COMP circuit
breaker (CB17) as necessary.
96−00−00
Defective air condition
disable relay K7−5.
Replace the relay. 96−00−00
Open wire between relay
K7−5−X2 and P104−ZF
(on the IIDS).
Do a test on the wires for a
serviceable condition. Make
repairs as necessary.
20−60−00
Defective compressor
solenoid.
Replace the compressor. 21−50−00
Defective time delay relay
K7−3/4.
Replace the time delay relay. 96−00−00
System pressure is low.
Service the air conditioning
system.
12−00−00
A leak in the air conditioning
system. Repair as necessary.
12−00−00
Defective low pressure
switch.
Replace the low pressure
switch.
21−50−00
System pressure is high.
Defective thermostatic
expansion valve (TXV).
Replace the valve.
21−50−00
Condenser is dirty, clean as
necessary. Remove blockage
from the air inlet as necessary.
21−50−00
EARLY CONFIG −
Condenser fans do not operate.
Repair or replace as necessary.
21−50−00
Defective IIDS. Replace the IIDS. 95−30−00