TM 9-4120-404-14
(27) Electromagnetic Interference Filter -- Reduces the radiated and conducted electromagnetic interference
created by the air conditioner electrical components to an acceptable level.
(28) Compressor Relay -- Controls power to the compressor and is activated by the logic box assembly.
(29) Relief Valve --This safety valve opens when the refrigerant discharge line pressure rises above 540 psig
2
(37.97 kg/cm
).
(30) Actuating Cylinder -- This hydraulic cylinder operates the discharge louver assembly. It will start to open
2
the louver assembly at 150 to 180 psig (10.55 to 12.66 kg/cm
) and fully open the louver assembly at
2
220 to 260 psig (15.74 to 18.28 kg/cm
) compressor discharge pressure to allow unit operation
when outside temperature is low.
(31) Heater Relay -- Controls power to the heating elements and is activated by the logic box assembly.
(32) Mode Selector Switch -- Provides selection of unit operating modes.
(33) Temperature Control Potentiometer -- This control allows adjustment of the conditioned air temperature
while operating in either the COOL or HEAT modes.
(34) Light Emitting Diodes (Fault Lights) -- These lights provide operating and maintenance personnel with
an indication of unit operating problems.
(35) Logic Box Assembly -- Electronic device that monitors unit sensors and control settings to operate the unit
control the fault lights.
(36) Motor Controller Assembly -- Electronic device that conditions and regulates motor and heater supply
power according to signals sent from the logic box assembly.
(37) Transformer -- Reduces the main line input voltage to the required control circuit voltage level.
1-5
