PRESSURE SWITCHES. - TM-5-4120-339-140091

TM 5-4120-339-14

TO 35E9-253-1

(1) Refer to figure 4-5 and install pressure gages with R-22 refrigerant cylinder in an upright position.

(2) Start the air conditioner by turning the selector switch to "COOL" position.

(3) Turn the thermostat control knob counter clockwise to its limit.

(4) Open charging cylinder outlet valve about two turns.

(5) Open the suction pressure service valve slowly while observing the sight glass. When the bubbles

disappear and the sight glass becomes clear, close the suction service valve.

(6) Allow the air conditioner to continue to run for 10 minutes. If bubbles reappear, add refrigerant until

bubbles disappear again. Continue this cycle until no more bubbles appear. Add refrigerant a little at a time so that the

system is not overcharged.

(7) When sight glass remains clear, turn selector switch to "OFF".

(8) Refer to figure 4-5 and remove manifold, gages and charging cylinder.

4-12.

PRESSURE SWITCHES.

WARNING

Disconnect the air conditioner from the electrical power source before performing

maintenance on the pressure switches.

a. Pressure Control Switch S8.

(1) Removal.

(a) Turn the selector switch to the "OFF" position and disconnect the air conditioner from the electrical

power source.

(b) Refer to figure 4-2 and release refrigerant from the system.

(d) Refer to figure 3-4 and remove the condenser fan.

(e) (Model TM-9KV-208-3-60 only) Refer to figure 4-6 and remove the pressure control switch by holding

the switch and loosening the flare nut at the base of the switch. It is not necessary to remove the electrical leads from the

wire bundle unless the switch is to be replaced.

(f) (Model F9000T3-2 only) Switch S8 is located behind switches S5 and S6; see figure 4-7 and remove

S5 and S6 in accordance with removal steps 1 through 4. Remove two screws and washers and pull switch S8 out of

switch box. Tag and disconnect wire leads if switch S8 is to be replaced. Loosen flare nut at end of capillary line and

remove from tubing connection point.

(2) Test. Refer to figure 4-6 and test the pressure control switch S8.

(3) Replace. Replace pressure control switch S8 if damage would impair serviceability or if failure occurs

during testing.

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