TM 5-6115-434-12
Table 3-3. Troubleshooting
Malfunction
Probable cause
Corrective action
20
Ventilating air system will
b. Recirculating fan circuit
b. Reset (press) recirculating
not start.
breakers (CB15 and CB16)
fans circuit breakers. Re-
-Continued.
open or failed.
place failed circuit break-
ers (CB15 and CB16)
as required (para 3-56d).
c. Vent system select switch
c. Replace failed vent system
(S14) failed.
select switch (S14) (para
3-55h).
d. Mode select switch (S16)
d. Replace failed mode select
failed.
switch (S16) (para 3-55h).
e. Recirculating fan contractors
e. Replace failed recirculating
(K25) or (K26) failed.
fan contactors (K25 or
K26) as required (para
3-57b).
f. Diode (CR12) failed
f. Replace failed diode (CR12).
g. Other causes
g. Refer other causes to direct
and general support main-
tenance personnel.
21
Heated air system will
a. No 400 Hz power
a. Refer to para 2-16b for
not deliver heated
operation to deliver 400
air.
Hz electrical power. Re-
place failed components,
as required.
b. Recirculating fans circuit
b. Reset (press) circuit break-
breakers (CB15) or (CB16)
ers. Replace failed recircu-
open or failed.
lating fan circuit breakers
(CB15) or (CB16), as
.required (para 3-6d).
c. Heat system select switch
c. Replace failed heat system
(S31) failed.
select switch (S31) (para
3-55h).
d. Mode selector switch (S16)
d. Replace failed mode selector
failed.
switch (S16) (para 3-55h).
e. Load control valve failed
e. Replace failed load control
valve (para 3-70).
f. Air pressure regulator failed
f. Replace failed air pressure
regulator (para 3-17).
g. Load control thermostat
g. Refer to para 3-8e (2) for
improperly adjusted or
adjustment procedure. If
failed.
thermostat cannot be
adjusted, replace load con-
trol thermostat (para 3-73).
h. Heat temperature senses (R1,
h. Replace failed heat tempera-
R2, R5, R6) failed.
ture sensors (R1, R2, R5,
R6) as required.
i. Heat system flow control
i. Replace failed heat system
valve failed.
flow control valve (para
3-74).
j. Overtemperature thermoswitch
j. Replace failed overtempera-
(TS5) or (TS9) failed.
ture thermoswitch (TS5)
or (TS9), as required.
k. Diode (CR15) or (CR16)
k. Replace failed diode (CR15)
failed.
or (CR16), as required.
l. Jumper plug (J93) not in-
l. Install or replace jumper
stalled or missing.
plug (J93), as required.
m. Other causes
m. Refer other causes to direct
and general support main-
tenance personnel.
3-14
