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

9.4 How to Service the DSP Air Compressor

Before servicing the DSP 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).
Air Intake Filter – (Replace Bi-Annually)
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Upper-Left Cover
Air Intake Filter
Air Intake
Filter Cover
Wing Nut
If the air intake filter is clogged with dust/dirt particles, less air is taken in and discharge air temperature
rises. If the compressor room environment is dusty or dirty, service the air intake filter more frequently
than instructed on the Maintenance Schedule.
Drain check (intercooler, after cooler) (daily), strainer element (for
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drain) cleaning (bi-annually) orifice cleaning (annually)
■ Drain condition check
Condensate may drain from the compressor according to operating conditions (high humidity, etc.).
C heck the drainage daily, periodically inspect and clean the strainer and orifices. For details concerning how to check
the drainage, see page 6. The solenoid valve of the intercooler and after cooler operates automatically every 20 seconds
to discharge water together with air.
9. MAINTAINING THE DSP [How to Service the DSP Air Compressor]
Differential
Pressure
Sensor
CAUTION
A differential 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 4.98 kPa (0.7 psi) during operation,
AIR FILTER CLOG appears on the display. 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 DSP air compressor and turn off the main
power supply.
② Open the upper-left cover.
③ Remove the filter cover and wipe away the dirt from
inside the filter duct.
④ Loosen the wing nut and remove the filter element.
Remove large dirt by tapping the filter element lightly,
and clean the inside by blowing the remaining dirt
with compressed air.
⑤ If the filter element is excessively dirty, clean by
immersing in for about 30 minutes in a neutral deter-
gent diluted with water. After doing so, rinse well
with clean water (max. water pressure 0.27 MPa (39
psi)). Shake off the excess water and allow it to dry.
⑥ After making sure the filter element is dry, mount the
filter element in the filter duct and fasten with the
wing nut.
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