TM 5-4310-375-14
(6) Turn main power source on, start the unit (para 2-7.a) and check the adjustment. To check cut-in pressure,
open the drain cock on bottom of receiver tank and allow air pressure to fall below 175 psi (12.3 kgs/cm2).
Close drain cock and motor should start immediately.
(7) Repeat above adjustments as necessary to obtain proper operating pressures.
(8) Install switch cover (8) and secure with captive cover screw.
b. Removal. To remove pressure switch for repair or replacement, proceed as follows:
WARNING
Electricity is dangerous. Before performing any maintenance or adjustments,
be sure the electrical power is turned off. Never depend on the ON-OFF
switch. Turn power off at the source.
(1) Turn main power OFF at the source.
(2) Disconnect compressor unloader line (4, fig 5-2) from pressure switch unloader (9).
(3) Unscrew pressure switch captive cover screw and remove pressure switch cover (8).
(4) Disconnect and tag wiring leads from switch terminals.
(5) Remove the conduit connector (5) and elbow (6) with conduit and wires.
(6) Unscrew and remove pressure switch assembly (7) from receiver tank fitting.
c. Cleaning, Inspection and Repair.
WARNING
When cleaning with compressed air, nozzle pressure shall not exceed 30 psi
(2.11 kgs/cm2). Eye protection is required.
WARNING
When cleaning electrical parts with trichloroethane, provide adequate
ventilation. Avoid prolonged breathing of vapors and minimize contact
with skin.
(1) Use compressed air to remove dust and dirt from pressure switch. Wipe components with a clean, lint-free cloth
dampened with trichloroethane, or an approved electrical component cleaning solvent.
NOTE
A pressure switch spare parts kit is available. The kit consists of the board and
contacts (10) and diaphragm (11). Disassembly beyond that listed below is not
recommended. (Refer to TM 5-4310-375-24P.)
(2) Unscrew and remove nut securing unloader (9) to body (21). Examine for plugging and free action of unloading
pin. Replace a defective unloader (9).
5-8
