Troubleshooting - Miller Bobcat 200 Air Pak Owner's Manual

11-9. Troubleshooting

A. Compressor Troubleshooting
Trouble
Air compressor does not operate; no air
pressure on gauge; no
engagement.
Air compressor stops producing air, or
air compressor cycles on and off.
Compressor operates, but air pressure
is low.
.
A complete Parts List is available at www.MillerWelds.com
Place Air Compressor switch in an On position. If compressor is turned off, wait for air pressure to bleed
clutch off before turning compressor on again.
Pressure downstream of compressor outlet above MIN pressure setting keeps compressor from en-
gaging. Compressor will engage when outlet pressure reduces below MIN pressure. See Section 7-1
for pressure setting procedure.
Check for over pressure. Check pressure settings and reduce if necessary (see Section 7-1). Turn Air
Compressor switch off to reset.
Check for over temperature. Allow unit to cool. Recirculation or open covers may cause overheating. Be
sure all covers, panels, and doors are in place. Operate in area with proper airflow. Automatic shutdown
stops compressor if compressor temperature is too high.
Check compressor belt and tension. Be sure correct belt is used and is properly installed. Replace belt
if damaged or worn.
Have Factory Authorized Service Agent check air compressor control circuit and clutch.
Compressor idle down causes compressor to turn off when set pressure is reached. See Section 7-2.
During air use, compressor pressure will continue to decrease if using more than 30 CFM. Decrease load,
or allow compressor to build pressure between loads. Compressor will automatically produce air when
a load is applied, unless it is a light load such as an air leak. For light loads, pressure will decrease to MIN
pressure and then increase to MAX pressure.
Check for air leaks downstream of compressor outlet. Air leaks cause more frequent compressor cycling.
Repair all air leaks.
Check for over pressure. Check pressure settings and reduce if necessary (see Section 7-1). Turn Air
Compressor switch off to reset.
Check compressor oil level (see Section 5-5). Automatic shutdown stops compressor if compressor tem-
perature is too high.
Check for over temperature. Allow unit to cool. Recirculation or open covers may cause overheating. Be
sure all covers, panels, and doors are in place. Operate in area with proper airflow. Automatic shutdown
stops compressor if compressor temperature is too high.
Have Factory Authorized Service Agent check and clean compressor cooler core. Automatic shutdown
stops compressor if compressor temperature is too high.
Verify adequate air flow to compressor. Check for blocked air intake.
Have Factory Authorized Service Agent check operation of over pressure switch S2.
Check for leaks in air lines and hoses.
Adjust compressor air pressure (see Section 7-2).
Reduce air demand/close air outlet valve.
Run compressor to increase temperature above freezing.
Check for frozen lines or hoses downstream from compressor outlet.
Blowdown valve is frozen. Run compressor to build heat and blowdown valve will return to normal opera-
tion.
Check air compressor air cleaner (see Section 11-3).
Check compressor oil level (see Section 5-5).
Check air/oil separator, and replace if plugged (see Section 11-3).
Check compressor belt and tension. Be sure correct belt is used and is properly installed. Replace belt
if damaged or worn.
Have Factory Authorized Service Agent check solenoid blow down valve, and for leaks in control lines.
Also check air compressor for rated output.
Remedy
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