How To Service The Air Compressor - Hitachi NEXT Series Instruction Manual

9. MAINTENANCE [How to Service the Air Compressor]

9.4 How to Service the Air Compressor

Before servicing the air compressor, stop it, disconnect the power (turn off the earth leakage (ground) circuit
breaker) and verify that the compressor's internal pressure has dropped to atmospheric pressure.
The maintenance intervals shown refer to the standard Maintenance Schedule (A).
Replacement of Air Intake Filter (Bi-Annually)
1
Differential pressure sensor
Duct
If the air intake filter is clogged with dust/dirt particles; Differential pressure (resistance of flow) across
the air intake filter increases, which results in decreased air intake to the airend and a rise in discharge
air temperature. To avoid a problem, service the air intake filter regularly. If the compressor room
environment is dusty or dirty, service the air intake filter more frequently than instructed on the
Maintenance Schedule.
88
Air Intake filter
Wing nut
Cover
CAUTION
A pressure sensor is provided on the suction throttle
valve to detect the pressure differential across the air
intake filter. When the sensor detects a pressure
differential as large as 0.72 psi (4.98 kPa) during
operation, AIR FILTER appears on the LCD display with
E0.21 on digital monitor. If this occurs, clean or replace
the air intake filter in accordance with Maintenance
Schedule (A) or (B). The procedure for cleaning the air
intake filter is as follows.
① Stop the air compressor, disconnect the power and
verify no internal pressure.
② Remove the front door (1).
③ Remove the cover and wipe away the dirt inside of the
duct before removing the air intake filter.
④ Loosen the wing nut and remove the air intake filter.
Make sure the contamination and/or dust doesn't
enter the airend side.
⑤ Tap the air intake filter to remove large particles.
Then blow air to clean the surface of filter.
⑥ In the case of oily or carbon dust, dip the element into
neutral detergent and water solution for about 30
minutes. Rinse the element several times with clean
water (water pressure is less than 39 psi (0.27MPa))
and air-dry it. Confirm the element is dried
completely.
⑦ Reinstall and tighten the wing nut.