TM 5-6115-586-34
Table 2-2. Troubleshooting-Continued
Malfunction
Probable Cause
Corrective Action
14.
60 Hz voltmeter out of limits.
Meter out of adjustment.
Adjust meter (para 5-26).
15.
400 Hz frequency meter out of
a. Meter out of adjustment.
limits. (True frequency
b. Replace 400 Hz protective panel
established with test instrument.)
circuit.
(para p-33).
16.
400 Hz ammeter out of limits.
Meter out of adjustment.
Adjust meter (para 5-26).
17.
400 Hz ammeter does not in-
dicate.
5-33).
b. Defective meter.
26).
18. 400 Hz voltmeter out of limits.
Meter out of adjustment.
Adjust meter (para 5-26).
19. Heating system does not operate. a. Load control valve does not have
a. Tighten fittings; check for
Fans run but load control valve
sufficient pneumatic supply.
damaged tubes or fittings; check
does not open.
for obstructions in supply fittings
b. Lockout relay (K42A or K42B)
b. Replace relay (K42A or K42B).
failed.
(see TM 5-6115-586-12.)
20. Heat valves do not control. Load a. Dummy plug (P93) removed.
a. Install plug (P93).
(see TM 5-
control valve operates
6115-586-12.)
satisfactorily.
b. Temperature sensors (RT1, RT2,
b. Replace defective sensor.(see TM
RT5, or RT6) failed.
5-6115-586-12.)
c. Temperature controllers (S19 or
c. Replace switches (S19 or S20).(see
S20) failed.
TM 5-6115-586-12.)
d. Heat system flow control selectors
d. Replace selectors (S35 or S36).
(S35) or (S36) failed.
(see TM 5-6115-586-12.)
21. One or both cooled air systems
a. Mode select switch (S16) failed.
a. Replace switch (S16).(see TM 5-
will not actuate from panel. Main
6115-586-12).
contactor operation satisfactory. b. System select switch (S15) failed.
b. Replace switch (S15).(see TM 5-
6115-586-12.)
c. Lockout relay (K42A or 42B
failed).
(see TM 5-6115-586-12.)
22. Condenser fans do not operate.
a. Condenser air discharge door
a. Unlock switches or replace
switches (S27 and S28) are
switch (S27 or S28).(see TM 5-
locked open or have failed.
6115-586-12.)
b. Condenser fan contactors (K23
b. Replace contactors (K23 or K24).
and K24) have failed.
(see TM 5-6115-586-12.)
c. Circuit breakers (CB13 and
c. Replace circuit breakers (CB13 or
CB17) failed.
CB17). (see TM 5-6115-586-
12.)
23. Condenser fans operate but
compressor does not energize.
K18) failed.
TM 5-6115-586-12.)
b. Compressor contactors (K19 or
b. Replace contactors (K19 or K20).
K20) failed.
(see TM 5-6115-586-12.)
c. Compressor circuit breakers
c. Replace circuit breakers (CB14
(CB14 and CB18) failed.
and CB18). (see TM 5-6115-
586-12.)
d. Condenser fan interlock switches
d. Adjust attitude of switches (S33 or
(S33 and S34) do not close.
S34) or replace if defective. (see
TM 5-6115-586-12.)
e. Compressor overtemperature
e. Cool compressor or replace
switches (TS7 and TS8) open.
defective thermal switch (TS7 or
TS8) (para 6-4).
f. Compressor overpressure switches
f. Check refrigeration system for over
(S17 and S18) open.
pressurization. Replace switches
(S17 and S18) if defective (para
24. Condenser fans and compressors a. Temperature sensors (RT3, RT4)
a. Replace defective temperature
operate but system does not
failed.
sensor (para 5-23).
control. (Ambient temperature is b. Air conditioning temperature
b. Replace switches (S20 or S21).
between 60and 90F.)
controllers (S20 and S21) failed.
(see TM 5-6115-586-12.)
c. Remote temperature relav (K40)
c. Replace relay (K40).(see TM 5-
failed.
6115-586-12.)
d. Anti-ice relay (K41) failed.
d. Replace relay (K41).(see TM 5-
6115-586-12.)
e. Anti-ice sensors (TS10 and TS11)
e. Replace thermal sensors (TS10 or
failed.
TS11) (para 5-14).
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