Hitachi S-4800 manual Troubleshooting of Air Compressor, Symptom Probable Cause Remedy

4.3.2Troubleshooting of Air Compressor

If the air compressor becomes faulty, reference should be made to the following table.

	Symptom	Probable Cause	Remedy
Air compressor rotates.
	Pressure does not rise	Drain or stop valve leaks.	Retighten. If the valve still leaks,
	at all or rises very		replace with a new one.
	slowly.
		Packing, screw or seal is	Retighten or replace the packing
		defective.	with a new one.
		Safety valve leaks.	Replace with a new one.
		Air valve is defective.	Clean or replace with a new one.
		Suction filter has clogged.	Clean or replace with a new one.
		Piston ring has worn.	Replace with a new one.
		Starting unloader is faulty.	Ask service agent for repair.
		Pressure gauge reading is	Replace with a new one.
		improper.
	Maximum pressure	Pressure switch is faulty.	Adjust or replace with a new one.
	limit is exceeded.
		Pressure gauge reading is	Replace with a new one.
		improper.
	Abnormal sound has	Push solenoid is faulty.	Ask service agent for repair.
	been emitted.
		Piston hits air valve.	Ask service agent for repair.
		Bearing is defective.	Ask service agent for repair.
		Rider ring has worn.	Replace with a new one.
		Installation is inappropriate.	Install on level floor.
	Motor overheats.	Sliding part has scorched.	Ask service agent for repair.
		Motor is abnormal.	Ask service agent for repair.
Air compressor does not rotate.
	Motor does not whir to	Pressure switch is faulty.	Replace with a new one.
	drive.
		Protector is actuated.	Stop operation, and then restart.
	Motor whirs to drive.	Voltage has dropped.	Replace wires with the specified
			ones.
		Air valve leaks.	Replace with a new one.
		Starting unloader is faulty.	Ask service agent for repair.

•When asking the service agent for repair, please notify them of the following.

1. Model code 2. Symptom of trouble 3. Location of installation site

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