TM 9-4110-255-14
5-16. REFRIGERANT SYSTEM PRESSURE CHECK . - Continued
WARNING
Engines have fast moving parts that can injure hands, fingers, etc. Take special care while in
operation. Engine parts, particularly the exhaust system, can be very hot and cause severe
burns.
(3) Turn the refrigeration unit on (para 2-5) and operate at desired setting.
(4) With the refrigeration unit operating, allow service manifold gages to stabilize. Compare readings with
those listed in Table 5-1.
(a) If discharge and suction pressure are at, or near, the same value, defrost solenoid valve (L2) or
compressor (B1) failure is indicated.
(b) If discharge pressure is low and suction pressure is normal, a low refrgerant charge is indicated.
i
(c) If discharge pressure is normal and suction pressure is either high, or low, failure of the expansion
valve is indicated.
(d) If discharge pressure is high and suction pressure is normal, refrigerant overcharge is indicated.
(5) When pressure tests are completed, turn the refrigeration unit off (para 2-7) and disconnect battery.
NOTE
FOLLOW-ON MAINTENANCE:
Remove service manifold (para 5-9).
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