TM 5-3820-256-10
(b)
Adjust the engine throttle (7, figure 2-11) to bring the engine speed to 1400 rpm as observed on
tachometer (4).
(c)
Check that the on/off switch on the air compressor panel (11, figure 2-3) is ON. Check that the mud
pump reset switch (2, figure 2-2) is pushed in.
(d)
At the operator's control panel, set the mud pump switch (1, figure 2-2) to ON. (Use this same switch
to stop mud pump operation.).
(e)
Upon completion, flush and clean system with water.
d. Air compressor system.
NOTE
Before operating the compressor, connect the discharge line to the compressor. The drill string should
be in drilling position (in the hole or prepared to start drilling the hole). Do not operate the compressor
with the kelly retracted in the mast.
(1)
Connect the discharge piping to the air compressor. (See paragraph 2-9, g.) Open discharge valve (4,
figure 2-28); close discharge valve (5).
(2)
Check that the on/off switch on the air compressor panel (11, figure 2-3) is ON. Check that compressor
reset switch (10) is pushed in.
(3)
Adjust the engine throttle (7, figure 2-11) to bring the engine speed to 1 200 rpm as observed on tachometer
(4).
(4)
At the operator's control panel, set the compressor switch (4, figure 2-3) to ON to engage the compressor
clutch and operate compressor.
(5)
After the compressor runs for approximately 20 seconds, increase engine speed to 2100 rpm.
(6)
When air pressure gage (1, figure 2-3) reaches approximately 45 psi, set the load switch (3) to ON. The
compressed air system will develop maximum pressure of 215 psi (during drilling, pressure will fluctuate
slightly.) (7) To shut down the compressor, set the load switch (3, figure 2-3) to OFF to unload the
compressor. Lower engine speed to 1200 rpm. When the gage (2) pressure indicates about 90 psi, set the
power switch (4) to OFF. Open blowdown vavle (3, figure 2-5) to release trapped air.
e. Force feed lubricator.
The force feed lubricator supplies oil to the air discharge line during hard-rock, air-drilling
operations using a down-the-hole hammer. (See FM 5-166 for information about when to use the hammer and
lubricator.) To operate the lubricator, proceed as follows:
(1)
Be sure the reservoir has been filled with oil. Check sight glass (2, figure 2-6). Open the force feed
lubricator shutoff valve (3).
(2)
Start the air compressor (see above).
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