Air Compressor Gauge And Regulator; Air Compressor Overload Protection - Miller TRAILBLAZER 302 AIR PAK Owner's Manual

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A complete Parts List is available at www.MillerWelds.com

7-2. Air Compressor Gauge And Regulator

1
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The air pressure gauge reads the air
compressor line pressure. Air pres-
sure in the compressor case may be
high even when the gauge reads
zero. Wait 10 minutes for compres-
sor blow down cycle to complete be-
fore checking/adding oil or perform-
ing maintenance.
.
Weld output and generator power are
reduced when the air compressor is
on.
With the compressor on, weld or gen-
erator loads will cause the engine to
run at 3600 RPM.
1 Air Compressor Gauge
2 Air Pressure Regulator

7-3. Air Compressor Overload Protection

OM-229 930 Page 38
2
Adjust system pressure with the regulator.
Set pressure in the no-flow condition only.
To reduce engine load and allow higher
weld and generator output, set at lowest
possible pressure for the job.
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Set pressure in the 80 − 100 psi range
to operate plasma cutting equipment or
to gouge (CAC-A). Set pressure in the
100 − 125 psi range to operate pneu-
matic tools.
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Do not set pressure above 150 psi. If
air pressure exceeds 150 psi the com-
pressor clutch will disengage and shut
down the compressor.
Do not set pressure below 80 psi. Com-
OVER PRES
COMP TEMP
Ref. 804 857-C / Ref. 245 069-A / 229 807-B
pressor will supply 80 psi regardless of
setting below 80 psi.
See Section 7-3 for air compressor over-
load information.
Models With Optional Air Dryer
For best results, maintain air pressure in air
dryer using compressed air. Air dryer pres-
sure helps "squeeze" the water from the
compressor air. Pressure in the air dryer
may drop if there is no equipment connec-
ted to the dryer, or if the connected equip-
ment provides little restriction (load) in the
downstream air line (open air line). Plasma
cutting and CAC-A torches provide enough
restriction (load) for proper air dryer per-
formance.
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See Section 10-5 for engine/genera-
tor overload protection.
Over Pressure Protection
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Do not set air pressure above 150 psi
(1034 kPa). If air pressure exceeds
150 psi the compressor clutch will
disengage and shut down the com-
pressor.
If the compressor shuts down due to high
pressure, use the Air Pressure regulator
to reduce the system pressure. See Sec-
tion 7-2.
The compressor is equipped with an
emergency relief valve that will open if
pressure reaches 200 psi (1380 kPa).
Over Temperature Protection
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The compressor is equipped with
high oil temperature shutdown. High
oil temperature can be caused by low
oil, hot air recirculation, blocked or
clogged cooler, or fan failure.
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When the temperature inside the unit
drops below 455 (75 C), internal
heaters activate to prevent air sys-
tem freeze-up. Ice in air system com-
ponents may cause an Over Pres-
sure condition.
Ref. 804 857-C / Ref. 245 069-A