Section IV. LIQUID LINE SOLENOID VALVE AND EQUALIZER SOLENOID VALVE

TM 5-4120-274-15

6-7. Low Pressure Switch

6-8. Fan Speed Pressure Switch

a Genenal. The low pressure switch prevents

a. General The fan speed switch changes the

the compressor from operating if the suction pres-

speed of the fan motor from low to high when

sure drops below 25 psig (pounds per square inch

the pressure reaches 425 psig (pounds per square

inch gage).

gage .

b. Removal. Refer to figure 3-13, and remove

b. Removal. Refer to figure 3-14, and remove

low pressure switch.

fan speed pressure switch.

c. Installation. Refer to figure 3-13, and install

c. Installation. Refer to figure 3-14, and in-

low pressure switch

stall fan speed pressure switch

Section IV. LIQUID LINE SOLENOID VALVE AND

EQUALIZER SOLENOID VALVE

c. Installation. Refer to figure 3-10, 3-11 and

6-9. Liquid Line Solenoid Valve

install equalizer solenoid valve (hot gas bypass

a. General The liquid line solenoid shuts off

solenid valve). Evacuate and recharge the re

flow of refrigerant to the evaporator coil when

frigeration system (para 5-21c and 5-21d).

the thermostat is satisfied

b. Removal Slow]y discharge refrigerant from

system ( para 5-21b). Refer to figure 3-6 and re-

move the liquid line solenoid valve.

c. Installation. Refer to figure 3-6 and install

the liquid line solenoid. Evacuate and recharge

refrigeration system (para 5-21c and 5-21d).

Caution: The solenoid valves must be dis

assembled before disconnecting the tubing from

the valve to avoid heat distortion. Refer to fig-

ure 6-1.

Caution: Solder the tubing to the body of

the valve before reassembling the valve to avoid

heat distortion. Refer to figure 6-1.

6-10. Equalizer Solenoid Valve (hot gas

solenoid valve)

a. General. The equalizer solenoid valve (hot

gas solenoid valve) actuated by the on-off switch

and serrves to equalize system pressures during

shutdown.

b. Removal. slowly refrigerant

from

system (para 5-21b). Refer to figure 3-10, 3-11

and remove the equalizer solenoid valve (hot gas

bypass solenoid valve).

Figure 6-1 Solenoid valve, disassembly and reassembly.

Section V. PRESSURE RELIEF VALVE

system (pare 5-21b). Refer to figure 3-6 and re

6-11. Pressure Relief Valve

move pressure relief valve.

a. General. The pressure relief valve protects

c. Installation. Refer to figure 3-6, and install

the refrigerant system from excessive pressure.

pressure relief valve. Evacuate (para 5-21c) and

b. Removal. Slowly discharge refrigerant from

recharge (para 5-21d the refrigeration system.

6-2