Compressor Troubleshooting - Miller ENPAK Owner's Manual

Trouble
Engine does not return to idle speed.
Engine speed does not remain con-
stant.
Engine overheats.
Engine coolant temperature low.
Engine does not remain at power
speed when a load is applied with
crane pendant speed switch in the Low
or Idle position.
During operation in near freezing tem-
peratures, engine starts and goes to
idle but stalls after a few minutes.
During operation in severe cold weath-
er, engine starts and goes to idle but
stalls after a few minutes.

9-3. Compressor Troubleshooting

Trouble
Air compressor does not operate; no air
pressure on gauge.
Air compressor stops after short period
of operation.
Low air pressure.
High air pressure.
Oil in air from compressor.
OM-240 113 Page 38
Remove all generator power loads, compressor loads, and hydraulic loads.
Check remote panel and crane pendant to see if system is locked in high speed.
Have Factory Authorized Service Agent check circuit board PC2 and current transformer CT1.
GFCI receptacle is not proper type for application. Replace with Miller approved GFCI device (see
Parts List).
Check error messages. Check oil and coolant levels.
Have Factory Authorized Service Agent check engine thermostat for proper operation. Replace if
necessary.
During operation in severe cold weather it may be necessary to restrict inlet cooling air by partially
blocking unit air inlet louvers. Do not restrict engine combustion air inlet or engine exhaust or exit
cooling air. Remove restriction when severe cold weather ends to prevent engine overheating.
For small loads, place crane pendant speed control switch in the High or Fast position, or push Power
Start button on remote control panel to lock in high speed.
Place crane pendant speed control switch in the High or Fast position until unit has been in operation
and loaded for a period of time.
Install engine manufacturer's kit for cold-weather operation. Normal maximum glow plug time is 10
seconds. In ambient temperatures below 0° F, glow plug time is 20 seconds maximum. Check glow
plug timing to ensure proper heating before cranking engine.
Cycle compressor to on position.
Check compressor belt tension. Be sure correct belt is used and is properly installed.
Have Factory Authorized Service Agent check inlet valve P-IC.
Have Factory Authorized Service Agent check air compressor control circuit and clutch.
Automatic shutdown stops compressor if compressor temperature is too high or over−pressure condition
occurs.
Check compressor oil level (see Section 5-3). Check for clogged oil cooler. Clean debris from oil cooler.
Recirculation or open covers may cause overheating. Be sure all covers, panels, and doors are in place.
Operate in area with proper airflow.
Check for over-pressure condition by turning on compressor and monitoring air pressure and remote dis-
play for error messages.
Check for leaks in air lines and hoses, including control line.
Adjust compressor air pressure using pressure regulator (P-PRV) (see Section 7-1).
Check air compressor air cleaner (see Section 8-7).
Have Factory Authorized Service Agent check compressor for rated output.
Adjust compressor air pressure using pressure regulator (P-PRV) (see Section 7-1).
Be sure control line is connected at proportional control (P-PC), and unload solenoid valve (P-USV).
Check for frozen pressure regulator (P-PRV) at proportional control (P-PC), frozen intake control (P-IC),
or frozen control lines.
Check compressor oil level (see Section 5-3). If oil level is too high, system becomes saturated with oil.
Change compressor air/oil separator if close to replacement hours (see Section 8-7).
Remedy
Remedy