This document provides instructions for safely operating a Hitachi DSP rotary screw air compressor. It warns that the air compressor has rotating parts and hot surfaces that can cause injury and must be stopped and cooled down before servicing. It also warns of electric shock hazards when servicing and that breathing compressed air can cause harm. Operators must read and understand the safety instructions fully before use.

1. Prior to operation of this air compressor,
ensure that all operators read and
understand this INSTRUCTION MANUAL
completely, thereby operating it safely
and properly.
Place the INSTRUCTION MANUAL near
the air compressor to make it available
at any time, and refer to it as the need
arises.
INSTRUCTION MANUAL
DSP-90ALN DSP-90AMN
DSP-100ALN DSP-100AMN
DSP-120AMN
DSP-100VAMN
● This INSTRUCTION MANUAL explains in detail
the important items that require attention;
observed as the following:
● Always observe notations of WARNING, CAUTION
and IMPORTANT, as they indicate considerable
risks to safety.
HITACHI Oil-Free Rotary Screw Air Compressor
NEXNEXTTseriesseries
Air-Cooled
DSP-90WLN DSP-90WMN
DSP-100WLN DSP-100WMN
DSP-120WMN
DSP-100VWMN
Water-Cooled
GRAPHIC DESCRIPTIONS:
WARNING ：This is a warning. If handled improp-
erly, death or severe injury could
result.
CAUTION ：This is a caution. If handled improp-
erly, injury and/or physical damage
could result.
Air-Cooled ：This graphic is air-cooled type.
：This graphic is water-cooled type.
：This graphic is Variable Speed-control
Drive (VSD) models.
Water-Cooled
IMPORTANT ：This graphic is for items that need
attention, other than WARNING and
CAUTION.
：This graphic is a page number reference.
TWO STAGE

2. How to Use This Instruction Manual
■ Model Number Nomenclature
● This Instruction Manual covers the standard models of the Hitachi DSP air compressor.
● This Instruction Manual intended to assist daily operators and maintenance personnel
in the installation, operation, control and service of the Hitachi DSP air compressor.
● Prior to operation of this air compressor, ensure that all operators read and understand
this INSTRUCTION MANUAL completely, thereby operating it safely and properly.
Place the INSTRUTION MANUAL near the air compressor to make it available at any
time, and refer to it as the need arises.
● If there are any questions or comments, please contact the local Hitachi distributor or
the nearest Hitachi office.
● Fill your DSP’s model name, Serial Number, etc. into the back cover of this Instruction Manual.
Such information may be helpful when ordering parts, periodic maintenance, and overhaul.
● Hitachi may make improvements and/or changes in the products described in this publication at any time without notice.
DS P - 100 V A 5 M N
Dry or Oil-Free Rotary
Screw Air Compressor
Packaged
N-Type (NEXT Series)
Main Voltage
(L: 200V class, M: 400V class)
Frequency (5: 50 Hz, 6: 60 Hz)
A: Air-Cooled, W: Water-Cooled
w/ V: VSD, w/o V: Fixed
Motor Output (kW)
Never remove a protective device from the air compressor or
modify the air compressor.
It is imperative to install an earth leakage (ground) circuit breaker
on the power cable. This prevents a ground fault accident.
DSP air compressors are not designed, intended or approved for
breathing air applications. Hitachi does not approve specialized
equipment for breathing air applications and assumes no respon-
sibility or liability for compressors used for breathing air services.
WARNING
■ International System of Units (SI)
For the unit of pressure the International System of Units (SI) is used throughout
this manual. To convert it into the conventional system of units, use the following
conversion formula:
7.14 kgf/cm2
= 0.70 MPa or 1 kgf/cm2
= 0.098 MPa

3. 1
Contents
1. SAFETY ………………………………………………………………………………………… 2
2. GENERAL DESCRIPTION 2.1 Appearance ……………………………………………………………………… 6
2.2 Components …………………………………………………………………… 8
2.3 Daily Operating Components ……………………………………………… 10
3. OPERATING THE DSP 3.1 Instrument Panel ……………………………………………………………… 12
3.2 Start/Stop Operation ………………………………………………………… 14
3.3 How to Use the liquid Crystal Display (LCD) ……………………………… 15
3.4 How to Use the Digital Monitor …………………………………………… 25
3.5 Daily Operation ………………………………………………………………… 32
3.6 Oil Mist Remover Daily Operation ………………………………………… 34
3.7 Adjusting the DSP ……………………………………………………………… 34
4. TROUBLESHOOTING 4.1 Protective Devices …………………………………………………………… 35
4.2 Troubleshooting the Air Compressor ……………………………………… 37
4.3 Troubleshooting the Oil Mist Remover …………………………………… 38
5. INSTALLING 5.1 Unpacking the DSP Air Compressor ……………………………………… 39
AND PIPING THE DSP 5.2 Conveying the DSP Air Compressor ……………………………………… 39
5.3 Installing the DSP Air Compressor ………………………………………… 40
5.4 Piping the DSP Air Compressor …………………………………………… 41
5.5 Ventilation of Air Compressor Room ……………………………………… 44
6. STARTUP OPERATION 6.1 Air Compressor ………………………………………………………………… 46
6.2 Oil Mist Remover ……………………………………………………………… 48
7. WIRING 7.1 Power Supply Transformer and Power Cable …………………………… 49
7.2 Connecting a Power Cable …………………………………………………… 49
7.3 Wiring Connection Diagram ………………………………………………… 51
7.4 Control Panel /LCD monitor Specifications ……………………………… 51
8. STANDARD COMPONENTS 8.1 Standard Components ………………………………………………………… 57
AND SUBSYSTEMS 8.2 Air/Oil Flow ……………………………………………………………………… 58
8.3 Cooling Water ………………………………………………………………… 63
8.4 Capacity Control System ……………………………………………………… 64
8.5 Outline of Oil Mist Remover Subsystem…………………………………… 69
9. MAINTAINING THE DSP 9.1 Air Compressor Maintenance ……………………………………………… 70
9.2 Standard Maintenance Schedule …………………………………………… 71
9.3 Oil Mist Remover Maintenance ……………………………………………… 75
9.4 How to Service the DSP Air Compressor ………………………………… 76
10. PRECAUTIONS WHEN THE COMPRESSOR IS TO BE IDLE FOR AN EXTENDED PERIOD OF TIME ………… 89
11. PARTS LIST ………………………………………………………………………………………… 90
12. WARRANTY, AFTER-SALES AND SERVICE …………………………………………………………… 114
13. OPERATION RECORD LOGBOOK…………………………………………………………………………… 115
14. STANDARD SPECIFICATIONS ……………………………………………………………………………… 116

4. 013B0816
012B1240012B1240
Rotating Parts!
●Keep hands and rods, etc. away from
the rotating parts (Cooling fans, etc.)
●Use caution at all times, when air com-
pressor is powered. The air compres-
sor may be capable of restarting with-
out hitting the START button.
●When the air compressor is operating,
do not remove or open the enclosure
panels and doors.
●Before servicing the air compressor,
stop it, disconnect the power, especially
when accessing any rotating parts.
WARNING
Hot Surface!
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
Heated!!
Air End
Discharge Air pipe
Hot Surface!
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
Air End
Discharge Air Pipe
Hot Surface!
Aftercooler
Intercooler
WARNING
Heated!!
WARNING
WARNING
Heated!!
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
To ensure safe and proper operation of the air compressor, it is indispensable to carefully
read and understand the following warnings and instructions detailed below. These warn-
ings and instructions are attached to the air compressor as shown in the figure below.
Air-Cooled DSP-90/120AN
100VAN
2
1. SAFETY

5. Do Not Breathe Air!
Discharge air can contain Carbon Monoxide and
other contaminants. Breathing the air can cause
severe injury or death.
High Pressure Air!
●High pressure air can cause severe injury or death.
Be careful when air compressor is operating.
Pressurized air can blow out of safety relief valves
and etc. at incredibly high velocities.
●When using compressed air to clean equipment,
use extreme caution and/or wear eye protection.
●Before servicing the air compressor, stop it,
disconnect the power, and relieve pressure before
removing filter, plug, fitting or cover.
Rotating Parts!
●Keep hands and rods, etc. away from the rotating
parts (Cooling fans, etc.)
●Use caution at all times, when air compressor is
powered. The air compressor may be capable of
restarting without hitting the START button.
●When the air compressor is operating, do not
remove or open the enclosure panels and doors.
●Before servicing the air compressor, stop it, dis-
connect the power, especially when accessing
any rotating parts.
Electric Shock Hazard!
●Before servicing or wiring the air compressor,
disconnect the power. This will prevent anyone
from turning on the power and causing an electric
shock that could lead to severe injury or death.
●Do not allow any unlicensed person to wire the air
compressor. Always use a licensed electrician.
●Ground the air compressor.
Electric Shock Hazard!
●Before servicing or wiring the
air compressor, disconnect
the power. This will prevent
anyone from turning on the
power and causing an elec-
tric shock that could lead to
severe injury or death.
●Do not allow any unlicensed
person to wire the air compres-
sor. Always use a licensed
electrician.
●Ground the air compressor.
WARNING
WARNING WARNING
WARNING
WARNING
Hot Surface!
●Do not directly touch the air end, discharge air
pipe,and coolers when the air compressor is
operating and immediately after it has stopped,
because these parts are heated then.
●Before servicing the air compressor (especially
when accessing to the heated parts), stop it, discon-
nect the power, and wait until it is cooled down.
WARNING
CAUTION
Precaution against Fire!
●Keep any other hazardous materials such as
flammable solvents away from the air compressor.
Also do not use fire nearby it; otherwise a spark
may enter the air compressor and burn it internally.
●Do not remove any protective relay s. Also do not
make a modification of the control circuit that may
result in impairing the protective relay s function.
Remember that the loss of the protective relay s
function may cause serious damage.
●Install an earth leakage circuit breaker between
the air compressor and the power supply. Do not
use a disconnector such as a knife switch
because it cannot protect the air compressor and
may cause burnout of the air end if a ground fault
has occurred.
3
1. SAFETY

6. 013B0816
012B1240012B1240
Hot Surface!
WARNING
Heated!!
Air End
Discharge Air pipe
Hot Surface!
WARNING
Air End
Discharge Air Pipe
Heated!!
Aftercooler
Intercooler
Heated!!
Hot Surface!
WARNING
WARNING
Rotating Parts!
●Keep hands and rods, etc. away from
the rotating parts (Cooling fans, etc.)
●Use caution at all times, when air com-
pressor is powered. The air compres-
sor may be capable of restarting with-
out hitting the START button.
●When the air compressor is operating,
do not remove or open the enclosure
panels and doors.
●Before servicing the air compressor,
stop it, disconnect the power, especially
when accessing any rotating parts.
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
●Do not directly touch any component
inside the air compressor enclosure
when the air compressor is operating
or immediately after it has stopped,
as the components are extremely hot
and can cause severe injury.
●Before servicing the air compressor,
stop it, disconnect the power, then
wait for the air compressor to cool
down.
Water-Cooled DSP-90/120WN
100VWN
4
1. SAFETY

7. Electric Shock Hazard!
WARNING
●Before servicing or wiring the
air compressor, disconnect
the power. This will prevent
anyone from turning on the
power and causing an elec-
tric shock that could lead to
severe injury or death.
●Do not allow any unlicensed
person to wire the air compres-
sor. Always use a licensed
electrician.
●Ground the air compressor.
Do Not Breathe Air!
Discharge air can contain Carbon Monoxide and
other contaminants. Breathing the air can cause
severe injury or death.
High Pressure Air!
●High pressure air can cause severe injury or death.
Be careful when air compressor is operating.
Pressurized air can blow out of safety relief valves
and etc. at incredibly high velocities.
●When using compressed air to clean equipment,
use extreme caution and/or wear eye protection.
●Before servicing the air compressor, stop it,
disconnect the power, and relieve pressure before
removing filter, plug, fitting or cover.
Rotating Parts!
●Keep hands and rods, etc. away from the rotating
parts (Cooling fans, etc.)
●Use caution at all times, when air compressor is
powered. The air compressor may be capable of
restarting without hitting the START button.
●When the air compressor is operating, do not
remove or open the enclosure panels and doors.
●Before servicing the air compressor, stop it, dis-
connect the power, especially when accessing
any rotating parts.
Electric Shock Hazard!
●Before servicing or wiring the air compressor,
disconnect the power. This will prevent anyone
from turning on the power and causing an electric
shock that could lead to severe injury or death.
●Do not allow any unlicensed person to wire the air
compressor. Always use a licensed electrician.
●Ground the air compressor.
WARNING WARNING
WARNING
WARNING
Hot Surface!
●Do not directly touch the air end, discharge air
pipe,and coolers when the air compressor is
operating and immediately after it has stopped,
because these parts are heated then.
●Before servicing the air compressor (especially
when accessing to the heated parts), stop it, discon-
nect the power, and wait until it is cooled down.
WARNING
CAUTION
Precaution against Fire!
●Keep any other hazardous materials such as
flammable solvents away from the air compressor.
Also do not use fire nearby it; otherwise a spark
may enter the air compressor and burn it internally.
●Do not remove any protective relay s. Also do not
make a modification of the control circuit that may
result in impairing the protective relay s function.
Remember that the loss of the protective relay s
function may cause serious damage.
●Install an earth leakage circuit breaker between
the air compressor and the power supply. Do not
use a disconnector such as a knife switch
because it cannot protect the air compressor and
may cause burnout of the air end if a ground fault
has occurred.
5
1. SAFETY

8. Enclosure
Oil Filling Port
Air Intake
(Inlet to the Air End)
Oil Level Gauge
OMR
Sling Fitting
Instrument Panel
Left Door
Plate of Operating /
Servicing Instructions
Air Exhaust
(Air Compressor Package)
Compressed Air Discharge
Power Supply Port
Air Intake
(Air Compressor Package)
Air Exhaust
Air Intake
Enclosure panels
lower the sound level
of the air compressor
package.
Use the port to fill the
gear case with oil.
This indicates the
quantity of the oil in
the gear case. Check
the oil level before
starting the DSP and
when operating it.
Use the sling fitting
when moving and
installing the DSP air
compressor.
See page pp. 12-13,
chapter 3, for details.
Read carefully the
plate before operating
and servicing the DSP.
Open the left door
only when servicing
the DSP air compres-
sor. Keep it closed
when operating the
DSP air compressor.
See page 69 for the
details
This panel discharges
the hot air generated
in the air compressor.
Check the specifica-
tions, power supply
and voltage before
connecting the power
supply.
Air Exhaust
Air Intake
Air Intake
Air Intake
Air Intake
Air Intake
(Air for inverter)
Air Intake
(Air for coolers)
2.1 Appearance
Air-Cooled DSP-90/120AN
100VAN
This section illustrates and describes the major components of the DSP air compressor. Be familiar
with the name, location and function of each component before using the DSP air compressor.
［Front View］
［Rear View］
6
2. GENERAL DESCRIPTION

9. Water-Cooled DSP-90/120WN
100VWN
Enclosure
Oil Filling Port
Air Intake
(Inlet to the Air End)
Oil Level Gauge
OMR
Sling Fitting
Instrument Panel
Left Door
Plate of Operating /
Servicing Instructions
Air Exhaust
(Air Compressor Package)
Compressed Air Discharge
Power Supply Port
Air Intake
(Air Compressor Package)
Air Exhaust Air Intake
Enclosure panels
lower the sound level
of the air compressor
package.
Use the port to fill the
gear case with oil.
This indicates the
quantity of the oil in
the gear case. Check
the oil level before
starting the DSP and
when operating it.
Use the sling fitting
when moving and
installing the DSP air
compressor.
See page pp. 12-13,
chapter 3, for details.
Read carefully the
plate before operating
and servicing the DSP.
Open the left door
only when servicing
the DSP air compres-
sor. Keep it closed
when operating the
DSP air compressor.
See page 69 for the
details
This panel discharges
the hot air generated
in the air compressor.
Check the specifica-
tions, power supply
and voltage before
connecting the power
supply.
Air Exhaust
Air Intake
Air Intake
Air Intake
Air Intake
Air Intake
(Air for inverter)
Air Intake
(Air for Package)
［Front View］
［Rear View］
7
2. GENERAL DESCRIPTION [Appearance]

10. 2.2 Components
Cooling Fan
Check Valve
Intercooler
Aftercooler
Oil Filter
Oil Cooler
Air Intake Filter
1st-Stage Air End
2nd-Stage Air End
Main Motor
Oil Mist Remover
Discharge Pipe
(Compressed Air Discharge)
Oil Level Gauge
Common Base
Starter /
Control Box
Safety Relief Valve Enclosure
Instrument Panel
High-Precooler
Air-Cooled DSP-90/120AN
100VAN
8
2. GENERAL DESCRIPTION [Components]

11. Cooling Fan
Check Valve
Intercooler
Aftercooler
Oil Filter
Oil Cooler
Air Intake Filter
1st-Stage Air End
2nd-Stage Air End
Main Motor
Oil Mist Remover
Discharge Pipe
(Compressed Air Discharge)
Oil Level Gauge
Common Base
Enclosure
Instrument Panel
Safety Relief Valve
Starter /
Control Box
Water-Cooled DSP-90/120WN
100VWN
9
2. GENERAL DESCRIPTION [Components]

12. Oil Filling Port
Oil Level Gauge
● Indicates the operation control section.
( For more information, see Chapter 3 on
page 12.)
● Operation ON → POWER light on.
● Start: Press START button → Operation Light on
during operation
● Stop: Press UNLOAD STOP button → unloading
operation stops for 5 minutes → Operation Light
off during operation
● Power OFF: → POWER light off
2.3 Daily Operating Components
Controls on the Instrument Panel
Aftercooler and Intercooler - Condensate Drain ValveLubricating Oil
Oil Level Gauge1 2
3 4
● Please use the following lubricating oil exclusively
for rotary compressor.
Manufacturer Description
IDEMITSU
DAPHNE NEW ROTARY
COMPRESSOR OIL A
COSMO OIL
LUBRICANTS
COSMO SCREW 32X
JAPAN ENERGY JOMO SCREW 32
SHELL CORENA OIL RS32
NIPPON OIL FAIRCOL RA32
EXXON MOBIL MOBIL RARUS 424J
*Oil company may change oil name without notice.
モニタ
メニュー
リセット
遠 方
機 能
電 源
運 転 停 止
運転状況
故 障
運転管理
負 荷
遠 方
起動待ち
設 定
自 動
UP/
DOWN
警 報
記 憶
表示切替/
ワイドモード
＋／−
AUTO
MONITOR
MENU
SET
SELECT/WIDE
2
RUNNING CONTROL
STARTREMOTE
1
FUNC
［× 10h］
ALARM
STR
REMOTE
RUNNING MODE
AUTO START
POWER
LOAD
RESET
SHUTDOWN
STOP
MONITOR
UNLOAD STOP
● Verify that air containing drainage is discharged
intermittently from the intercooler and after cooler
drain ports.
The higher the temperature and humidity, the more drain-
age is produced. Drainage may not be produced on the
intercooler side during winter.
[Fixed speed type]
Intercooler
drain port
After cooler
drain port
Intercooler
drain port
After cooler
drain port
Control pipe filter
drain port
● Verify that the oil level of the lubricating oil is
between the red lines during operation.
Lubricating oil circulates in the cooler and piping during
operation, so the position of the oil level differs when the
compressor is running and when it is off. The level rises
when the compressor stops running.
10
2. GENERAL DESCRIPTION [Daily Operating Components]

13. Control Line Filter
Manual Valve
Level Gauge
① Shut off the cooling water when the compressor is
off.
② Open the peacock for draining water. Also open
the valve of the water drain port and drain the
cooling water.
③ Be especially careful of freezing during the winter.
( For details, see page 63.)
Water drain peacock
Water drain port
Cooling Water5
● Normally use the UNLOAD STOP button to stop
the compressor. The compressor then unloads for
5 minutes and stops running.
(In the case of an emergency, press the STOP
button to stop operation.)
Stopping operation7
モニタ
メニュー
リセット
遠 方
機 能
電 源
運 転 停 止
運転状況
故 障
運転管理
負 荷
遠 方
起動待ち
設 定
自 動
UP/
DOWN
警 報
記 憶
表示切替/
ワイドモード
＋／−
AUTO
MONITOR
MENU
SET
SELECT/WIDE
2
RUNNING CONTROL
STARTREMOTE
1
FUNC
［× 10h］
ALARM
STR
REMOTE
RUNNING MODE
AUTO START
POWER
LOAD
RESET
SHUTDOWN
STOP
MONITOR
UNLOAD STOP
Keeping the second-stage air end as dry as possible
is essential for preventing it from rusting due to a long-
term operation suspension. When stopping the DSP,
therefore, execute an unloading operation and thereby
remove the moisture from the second-stage air end.
Controls on the Instrument Panel
[Fixed speed type]6
① Check the sight glass of the control line filter for
the accumulation of the condensate.
② To drain the accumulated condensate, slowly turn
to the left the condensate drain valve to open.
After draining the condensate, turn it to the right to
close.
11
2. GENERAL DESCRIPTION [Daily Operating Components]
IMPORTANT

14. 12
3. OPERATING THE DSP
3.1 Instrument Panel
＋／−
AUTO
MONITOR
MENU
SET
MONITOR
モニタ
メニュー
設 定
自 動
UP/
DOWN
Liquid Crystal Display
(LCD)
Displays the operation data,
various setting, shutdowns/
alarms information, etc.
( page 15)
MENU Button
Functions to display the
menu screen and move the
cursor.
( page 20)
+/- UP DOWN Buttons
Each of these buttons act
as an up-arrow, down-arrow
and right-arrow key.
( page 20)
SET Button
It saves any adjusted set
points.
Contrast adjustment
SET+[ ] button operation:
Brightens the display.
SET+[ ] button operation:
Darkens the display.
( page 24)
MONITOR Button
Enables movement within
each of the monitoring
displays (M1, M2) and the
message display (M3). This
button also enables you to
return to the M1 display from
the FUNCTION MENU
display ( page 15).
RESET Button
Reset the system or cancels
the shutdown/alarm circuit
( page 17).
ON (glowing) when an
automatic operation (an
AUTO operation, a schedul-
ing operation, or lead/lag
operation) is activated.
ON (flashing) when external
calendar or scheduling
operation is abnormal.
( page 18, 22)
AUTO light (yellow)

15. 13
3. OPERATING THE DSP [Instrument Panel]
SELECT/WIDE
2
RUNNING CONTROL
STARTREMOTE
1
FUNC
［× 10h］
ALARM
STR
REMOTE
RUNNING MODE
AUTO START
POWER
LOAD
RESET
SHUTDOWN
STOP
POWER light (yellow):
ON (glowing) when the power to the air compressor is turned on.
REMOTE light (green):
ON (glowing) when the REMOTE button is pressed in order to activate a remote operation.
ON (flashing) when an external remote-operation-activation switch has been turned on in order to
activate a remote operation. ( page 30)
LOAD light (yellow):
ON (glowing) when the air compressor is loading.
AUTO START light (green):
ON (glowing) while the air compressor is in a stop due to an AUTO operation, lead/lag operation, or
scheduling operation.
ON (blinking) while the air compressor is in a stop due to a restartable instantaneous power
interruption. ( page 18)
SHUTDOWN light (red): ON (either glowing or blinking) when a shutdown/alarm problem has
occurred. ( page 17)
リセット
遠 方
機 能
電 源
運 転 停 止
運転状況
故 障
運転管理
負 荷
遠 方
起動待ち
警 報
記 憶
表示切替/
ワイドモード
Digital Monitor
In addition to basic settings, used
to set various types of setting
values in combination with the LCD
monitor. ( page 24)
SELECT/WIDE Button/Light (Yellow)
Press to confirm various types of
setting values, shutdown history,
and setting status. ( page 26, 27)
To set to ECOMODE (energy
conservation mode) (standard type
only), press and hold the SELECT/
WIDE button for at least 7 seconds.
The light flashes and ECOMODE is
set.
START Button
Starts the air compressor.
The OPERATION light (red) turns
on while the compressor is running.
STOP Button
Stops the compressor immedi-
ately. ( page 14)
UNLOAD STOP Button
The air compressor will stop
after removing the condensate
from the air end. ( page 14)
REMOTE Button
Activates or deactivates a remote
start/stop operation locally or on
the instrument panel. it also acts
as a right-arrow key stop
( page 30).
UNLOAD STOP
Press this button to stop the air compressor.
The air compressor will stop after removing the
condensate from the air end.
※This stop button is effective while a stand alone operation.
RUNNING MODE Light

16. 3.2.1 Connecting the Power
When you connect the power, the POWER light turns
on and the LCD monitor displays the following screen
for 5 seconds, and then switches to the monitor screen
(M1) that displays control settings, discharge air pres-
sure, and total operating hours.
If phase is reversed, “Connection Error: Reverse
Phase” is displayed on the LCD monitor for setting
and connection inspection. In this case, switch 2 of the
3 main power cables.
If there is no phase, “Connection Error: No Phase” is
displayed on the LCD monitor. In this case, check the
power cables.
3.2 Start/Stop Operation
COMPRESSOR MONITOR
CONTROLLER
＊ The asterisk flashes when the clock and total run-
ning hours are engaged.
5 sec
3.2.2 Start/Stop
When the START button is pressed the START light
turns on and the compressor starts operating. When
running, the asterisk on the right side of running hours
flashes and running time is counted.
To stop, press the UNLOAD STOP button. Operation
stops when the air end and the air piping have dried for
5 minutes.
To stop the compressor immediately without unload-
ing, press the STOP button.
Note: If the STOP button is pressed while unloading,
the compressor stops immediately.
14
3. OPERATING THE DSP [Start/Stop Operation]

17. 15
3.3.1 How to Move between the Various Displays
■ Menu Displays
Follow the bottom line message on the display.
3.3 How to Use the liquid Crystal Display (LCD)
■ Monitoring Displays
There are three monitoring displays: M1, M2, and
M3. To move between these displays, press the
MONITOR button.
機能
FUNCTION
モニタ
MONITOR
モニタ
MONITOR
モニタ
MONITOR
モニタ
MONITOR
■ Monitoring Display（ p.16）
M1 Monitoring Display
M2 Monitoring Display
M3 Monitoring Display
■ Message Display（ p.18）
■ Function Menu Display（ p.20）
Function Menu Display
IMPORTANT
About the LCD Backlight
(1) In the event that no button has been used for 10
minutes, the LCD backlight automatically turns
OFF for protection to the display panel. It comes
ON again if any button is pressed, other than the
START and STOP buttons.
(2) If an event happens while the LCD backlight is off,
the backlight automatically turns ON and stays ON
as long as the event exists. The message display
is not displayed if the LCD monitor is in remote or
instant stop setting mode. Set after referring to “3.4
How to Use the Digital Monitor.” ( page 25)
15
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]
■ Message Display
There is only one message display: M3 (the con-
tents, however, vary from time to time). It is avail-
able only when some event (air compressor alarm or
shutdown, maintenance notice, etc.) has occurred.
Once an event happens, however, the M3 message
display appears immediately and automatically.
From the M3 display, pressing the MONITOR but-
ton will switch the LCD to the M1 or M2 monitoring
displays; but after approximately ten (10) seconds,
the M1 or M2 monitoring displays will revert back
to the M3 display.

18. 3.3.2 Typical Monitoring Displays
VSDA ＊ SAVE
ECOMODE
(Energy Conservation Mode)
“SAVE” is displayed on the monitor
screen.
Displayed when stop is limited for AUTO opera-
tion (standard: no symbol).
INTE ：Fixed speed type control (load/unload operation)
AUTO ：Fixed speed type control
(AUTO operation ＊ optional)
VSDB ：V type control (AUTO function off)
VSDA ：V type control (with AUTO function, V type standard)
EXIT ：Setting display when capacity control is executed
externally
MR ：Multiple unit control connection by communication
control
（1）
（2）
（3）
（4）
（5）
（6）
（7）
（8）
（9）
（10）
（11）
（10）
（11）
(1) Displays current time. Asterisk flashes.
(2) Indicates a capacity control type.
(3) Displays compressor discharge port pressure.
(4) Indicates interstage pressure (INTSTG. P), and oil
pressure (OIL PRESS).
Blink asterisk indicates running time is being meas-
ured.
(5) Displays load rate.
Indicates total running hours (RUN HR), total
loaded hours (LOAD HR), and total number of loads
(LOAD NOS.).
(6) Indicates a 1st-stage discharge temperature (DIS.
TEMP. 1), 2nd-stage discharge temperature (DIS.
When the DSP is operating normally, typical monitor-
ing displays appear as follows.
M1 Monitoring Display
M2 Monitoring Display
TEMP. 2), oil temperature (OIL TEMP.), 2nd-stage
suction temperature (2ND SUCT. TEMP.).
(In the case of V type, displays current value of
inverter primary side.)
(7) Displays an operating frequency of main motor.
(V type only. Fixed speed type displays ＊＊．＊ )
(8) Displays main motor output (reference value).
(9) Displays master or slave control status when in
lead/lag operation mode.
(10) Displays various pressures and temperatures.
(Asterisk indicates not in use.)
(11) Displays time remaining till next inspection as
maintenance period and next maintenance period.
Current is an approximate S-phase ampere.
Output is reference value of calculated power.
IMPORTANT
16
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

19. ■ Alarm Messages
① In the case an alarm occurs for the compressor, the ALARM light and contents / details displayed on alarm
screen on the LCD monitor flash and operation continues. There are 2 types of alarm screens: ALARM and
PROBLEM.
② Take the proper corrective action, and press the RESET button.
③ For further information, see pages 35, 36.
NOTE) Malfunction detection of water failure is available for only water cooled single stage compressor. Malfunction
detection of dryer is available for only built-in dryer models. Malfunction detection of oil water separator and
element is not available.
3.3.3 Message Displays
■ Shutdown Messages
① When a shutdown occurs for the compressor, the SHUTDOWN light and shutdown contents on the LCD monitor
(contents are displays on the left side and details are displayed on the right side) flash and the compressor stops
running. There are 2 types of screens for shutdown: SHUTDOWN and FAILURE.
② Take the proper corrective action, and press the RESET button.
③ For further information, see pages 35, 36.
NOTE) Malfunction detection of water failure is available for only water cooled single stage compressor. Malfunction
detection of dryer is available for only built-in dryer models. Malfunction detection of oil water separator and
element is not available.
(Example)
Example of temperature sensor malfunction, sensor 1 discon-
nection FAILURE and TEMPERATURE SENSOR flash and
the location of the abnormality is indicated.
IMPORTANT
(Example)
In the case ALARM and AIR FILTER flash while the com-
pressor is running, it indicates the filter is clogged.
(Example)
Example of battery replacement period.
(Example)
In the case the thermal relay trips and the compressor stops
running, SHUTDOWN and OVERLOAD flash and the mal-
function part of the main circuit is indicated.
17
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]
ALARM and PROBLEM messages are treated as alarms, but aside from connection abnormalities that make operation impos-
sible such as reverse phase and no phase when power is turned on, they also may indicate shutdown due to malfunction of the
communication status.

20. ■ Messages of Automatic Stop Display and Automatic Restart Display
When the DSP air compressor has automatically stopped, the following screen is displayed, the AUTO START light
flashes/lights, and the RESTART message screen and details of contents flash on the LCD monitor.
● SCHEDULED STOP: Schedule operation setting
＜ AUTO light ON ＞
When schedule is set on the scheduled operation
screen, displays state of operation being stopped by
preset time. Operation starts automatically when the
preset restart time comes.
● LEAD/LAG OPERATION STOP
(Note: applies only to machines equipped with two-
unit alternate operation.)
＜ AUTO light ON ＞
When the operation control mode is set to dual
or backup on the operation mode setting screen,
standby status of the slave machine in dual or backup
operation is indicated.
● DRYER PRESTARTED
(Note: Applies only to machines equipped with a
built-in dryer.)
＜ AUTO START light flashes ＞
When dryer prestart is set, the dryer starts operat-
ing in advance, and compressor stopped status is
indicated.
RESTART WAIT time is counted down.
● AUTO OPERATION
(Note: Applies only to machines equipped with
AUTO function)
＜ AUTO START light ON ＞
Indicates status stopped by low load when set to
AUTO operation. AUTO START light flashes during
restart limit while stopped, and RESTART WAIT
time is counted down.
● INSTANT STOP / RETRY
(Note: Retry applies to V type only.)
＜ AUTO START light flashes ＞
Displays status of restart for instantaneous power
interruption (IPI) restart and V type retry.
RESTART WAIT time is counted down.
18
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]
It takes maximum 50 seconds from AUTO STOP (when
AUTO setting is valid) to restart for V type.
IMPORTANT

21. ■ Maintenance Notice Messages
A maintenance date is determined by the amount of total operating hours or an elapsed calendar period, whichever
comes first. When the maintenance date or time arrives, the maintenance notice message appears on the display
under the heading of MAINTenance.
This function is an alarm display only, and does not output alarm externally.
Replace suction throttle valve consumable parts when inspection maintenance is displayed or the 1 million unloader
count alarm is given, whichever comes first.
NOTES:
1. MAINTenance can be reset, if the servicing is done earlier than expected and if the remaining operating time to next maintenance
is less than 1,500h
2. On the contrary, if the servicing is done after the maintenance notice has appeared, the remaining operating hours to the next main-
tenance has been zero until the maintenance is done. After maintenance and resetting the counter, new counting time starts just
after the maintenance notice message has appeared on the display.
If the inspection/maintenance is displayed, check the display contents, refer to maintenance standards
given in the compressor instruction manual and perform inspection/maintenance as soon as possible.
When inspection is complete, press and hold the SET button for at least 7 seconds.
The LCD monitor display contents then move to “Maintenance initial value completed” of the message
screen, and then return to the monitor screen 1 minute later.
(1) SWITCHED TO LOCAL.
If set to local by remote operation following shut-
down restoration, operation automatically returns
to local when shutdown occurs, and the message
is displayed for 1 minute. For setting details, see
“3.4 How to Use the Digital Monitor.”
( page 25)
(2) IN OVERRIDE MODE.
This message blinks when the DSP is in an over-
ride mode.
■ Other Messages
(3) UNLOAD STOP
If the UNLOAD STOP button is used, the display
flashes. The compressor unloads for 5 minutes
and then stops.
CAUTION
Every these calendar periods: Service the DSP according to the schedules:
0.5 years, 1.5 years, 2.5 years
3.5 years, 4.5 years, 5.5 years
Half-Yearly
1.0 years, 5.0 years Yearly + Half-Yearly
2.0 years, 4.0 years 2-Yearly + Yearly + Half-Yearly
3.0 years 3-Yearly + Yearly + Half-Yearly
6.0 years (for overhauling) 6-Yearly + 3-Yearly + 2-Yearly + Yearly + Half-Yearly
A Standard Maintenance Schedule (A) (for yearly 8,000-or-less operating hours)
B Standard Maintenance Schedule (B) (for yearly 4,000-or-less operating hours)
（1）
（2）
（3）
19
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

22. 3.3.4 How to Move within a Menu Display and to Change a Setting
ー [FUNCTION MENU] and [MAINTenance DATA MENU] ー
The method and procedure for altering settings is displayed using the following as an example.
① Press the MENU button displayed on monitor
screen 1 – 2.
② Select the number of the item to be set with the
△ ▽ buttons.
③ Enter with the SET button. The display then switch-
es to the detail setting screen for that item.
The following explanation uses [2. Operation Mode
Setting Screen] as an example.
How to Move within a [FUNCTION MENU] Display1
How to Select or Change a Setting within a Setting Display2
① When the display switches to the details screen,
move to the line to be altered with the △ ▽
buttons.
② Move to the item to be altered with the
▽
button.
③ Alter the setting value with the △ ▽ buttons.
④ After altering the setting value, press the SET but-
ton. The cursor moves to the number.
⑤ Press the SET button again.
The cursor moves to the first number at the top of
the screen and the setting contents are entered.
When setting is complete, pressing the MONITOR but-
ton once returns the display to the MENU screen, and
pressing it again returns to MONITOR screen 1.
The same procedure is used to alter settings for other
menus.
When altering settings of the LCD screen, number update
by button operation is slow. Press the buttons slowly
when altering settings.
IMPORTANT
Items with a dash next to their number cannot be altered
on the LCD monitor. In this case, alter from the digital
monitor while referring to the instructions manual for the
compressor.
IMPORTANT
①
③
④
⑤
②
20
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

23. 3.3.5 [FUNCTION MENU] − Setting Displays
Confirm settings by compressor alternate operation
specifications and multiple unit control (communica-
tion support). Wiring must be supplied separately for
use. Items for which a dash is displayed next to their
number cannot be set on the LCD monitor.
1. Operation control: Set operation control is dis-
played on the digital monitor.
2. LEAD/LAG operation time: Time setting for
alternate operation of a pair of compressors (set-
ting range: 0.1 – 99.9 hours; initial value: 8.0)
3. Switching conditions: Setting of conditions for
switching operation between a pair of compressors
4. Switching time: Switching time setting if switch-
ing conditions are “parallel” or “interval” (setting
range: 5 – 300 seconds, initial value: 15)
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩
If using the backup function, switch to the digital moni-
tor and set.
Model Setting Confirmation1
Operation Mode Settings2
The starter of settings can be confirm the software,
model and setting status of model-specific settings such
as capacity control. (Double asterisks are displayed for
settings that do not require confirmation.)
① Indicates board software version.
② Indicates compressor type.
③ Displays cooling type.
④ Displays the number of compressor stages.
⑤ Displays pressure specification.
⑥ Displays interstage pressure.
⑦ Indicates CT setting value.
⑧ Displays water failure detection conditions for water
cooled compressor.
⑨ Displays status of instantaneous power interruption
(IPI) restart setting.
⑩ Displays compressor number. (Must be distinguished
by number is using communication function.)
The screen provides the model and serves as a target for
setting status. Check the screen when making an inquiry.
IMPORTANT
IMPORTANT
Altered setting values can only be entered when the com-
pressor is not running.
IMPORTANT
5. BACKUP: Setting of pressure to start the backup
compressor when set to backup operation (range:
0.00 – 0.50 MPa, initial value: 0.05, difference from
control pressure in the minus direction).
6. UNLOAD: Pressure setting that manually unloads 1
unit when the preset pressure is reached in backup
operation (range: 0.00 – 0.50 MPa, initial value: 0.02, dif-
ference from control pressure in the minus direction).
7. DUAL TIME: Displays time remaining until switch for
dual / backup operation. Time is not counted down
when operating 2 units for backup operation. When
operation is stopped, remaining time is maintained.
8. SPEED CONTROL MODE: Displays control mode of V
type. An asterisk is displayed for the Fixed speed type.
Single Operates compressor independently.
STPR
Multiple
unit
Case where multiple unit control is executed by communication
function of multi roller EX (dedicated panel of NEXT Series).
Unit control is executed by RS485 communication according to
the settings. Requires separate setting of compressor number.
Dual
Operation alternates between a pair of compressors for
a preset amount of time. AUTO light lights.
Backup
Operation mode that adds pressure backup function to
dual operation. When pressure drops, the slave machine
starts. AUTO light lights.
OVER LAP
Method whereby first compressor is stopped after switching time for
the other unit in parallel operation when it is time for dual operation.
Interval
Method of operating the other compressor after stopping the
first one after switching time when it is time for dual operation.
21
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]
（ ）

24. If “SCHEDULE” is set, the AUTO light lights. If there is no
valid setting for time, the AUTO light flashes. Altered set-
ting can only be entered when the compressor is not run-
ning.
Scheduled operation can be set for 1 day (standard
equipment).
1. TYPE: Displays setting data for capacity control.
① Control settings set by the digital monitor can be
confirmed.
Fixed speed type: I (load/unload operation)/IP (AUTO
operation specifications ＊ optional)
V type: VB (AUTO function off)/ VA (AUTO opera-
tion specifications)
② Setting type of pressure set by the digital monitor
can be confirmed.
SETTING 1: Standard pressure setting;
SETTING 2: 2nd pressure setting
EXT: External load/unload setting
AUTO: Switches setting 1 and setting 2 by time.
③ Sets optional conditions. With standard specifica-
tions, displays “ordinary” characters.
2 - 3. OPTION: Used for options.
4 - 6. PRESSURE SETTING: Pressure settings set by
the digital monitor, target pressure and time limit can
be confirmed all at once on the LCD monitor. ④
7. TIME LIMIT: (Fixed speed type only)
Preset time limit can be confirmed.
The time limit is effective when ECOMODE (energy
conservation mode) is selected by pressing and hold-
ing the DISPLAY SWITCH button for at least 7 sec-
onds. The function sets energy conservation mode until
control pressure (unload start pressure) drops to the
target value if the load and unload repeat time clears
the time limit. If control pressure and recovery pres-
1. to 5. : Five Start/Stop Time Patterns
･ START: Starting Time
･ STOP: Stopping Time
･ Y or N :Yes starts or stops as scheduled.
2. DATA MEASUREMENT TIME: Time for recording
operation data twice a day can be set.
Recorded operation data can be confirmed by the “5”
operation data record screen.
Capacity CONTROL SETTING Display3
Schedule Setting4
If the time limit is altered, consult with your dealer or the
Hitachi Service Station given on the rear cover.
IMPORTANT
IMPORTANT
1. MODE: Scheduling Mode
The display shows an example setting of scheduled opera-
tion from 7:00 to 20:00. “19:07” indicates the current time
① ② ③
④
⑤
⑥
sure change time is measured and it exceeds the time
limit, control pressure is lowered so the time limit is no
longer exceeded. ⑤
(Time limit range: 30 - 120 seconds; initial value: 30 sec-
onds)
8. USE TIME: Sets time to use pressure of setting 2.
At that time, it displays automatic at the position of (2)
of the type. When start and stop time become the same
value, the automatic display is returned to setting 1 and
the function is stopped.
OFF Operates the DSP without a schedule.
SCHEDULED
Operates the DSP according to a daily 24-
hour calendar.
Settings are selectable when the DSP is in a stop.
IMPORTANT
Screen for confirming pressure settings for capacity
control. Pressure settings are set from the digital moni-
tor. Pressure settings consist of setting 1 and setting 2,
which can be used by setting time used.
22
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

25. ① Operation state is indicated by a symbol next to the
shutdown code.
L: Load, U: Unload, S: Stop
Displays alarm contents and code, date, time, state and
how many times alarm occurred. If the same alarm
continues to occur, it is overwritten as update data,
and the number of times the alarm occurs is updated.
The latest warning is recorded as item 1. If there is no
alarm, asterisks are displayed. The screen displays data
for 3 types, and the necessary data can be confirmed by
△ ▽ button operation.
①
Up to 6 items of alarm history are recorded aside from
shutdown history. Contents and occurrence state can be
confirmed. Select the number of the shutdown on the
SHUTDOWN HISTORY screen, press the SET button
and the operation state when the shutdown occurred
can furthermore be confirmed on the details screen.
● How to clear shutdown and alarm history.
If you want to clear the entire shutdown history and
alarm history, set F041 from the F mode of the dig-
ital monitor to “1: CLEAR HISTORY” while referring
to the instructions manual of the compressor.
Operation Data Display5 Alarm History7
Load Data Display6
Shutdown History Display8
Records date/time, pressure, current, temperature and
load status at that time as operating state recorded by
data measurement time. Up to 12 times can be record-
ed, after which the oldest data is deleted one at a time;
the latest data is displayed for item 1. The screen shows
record for 2 times, and the necessary data can be con-
firmed by △ ▽ button operation. If altered
before time is up, the data prior to change is main-
tained, and the time recorded as soon as the data is
altered changes.
1. and 2. - :Indicates the MONTH / DAY HOUR: MINUTE.
P - Represents a pressure (MPa) and indicates, from left
to right, the: Discharge air pressure, pressure data.
C - Current (A).
T - Represents a temperature（℃）and indicates from
left to right: 1st stage discharge air temperature,
2nd stage discharge air temperature.
L - Represents a load ratio percentage (%). and out put (kW).
If there is no data, an asterisk is displayed.
This display shows the averaged load data per day. Data
can be recorded for a maximum of six days; the 7th day
of averaged loaded data is automatically deleted and the
1st or most recent day of averaged data is added. The
most recent data is arranged at the top of the display.
The screen shows record for 2 times, and the neces-
sary data can be confirmed by △ ▽ button
operation. Data is averaged from operation start to
stop. The average is however fixed at 0.00 minutes in
the case of 24 hours operation.
If an alarm occurs on the digital monitor, shutdown
history is recorded. Up to 6 items of alarm history
however can be recorded aside from shutdown history.
Contents and occurrence state can be confirmed.
23
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

26. 3.3.6 Other Hardware Setting
Adjust the LCD brightness as follows:
To brighten:
Hold down the SET button and press the
MONITOR button.
To darken:
Hold down the SET button and press the
FUNCTION button.
The calendar and clock are set by Hitachi prior to
delivery. To reset the calendar and clock, please
contact the local Hitachi distributor.
The following is a table of contents that can be set by
the LCD monitor and digital monitor (next section).
Initial Setting
The language of the display can be switched to
Japanese, English or Chinese by the dip switch on
the back of the LCD monitor board. If the language
needs to be changed, consult with the local Hitachi
distributor.
3-Language Display Switch
Brightness Adjusting
Digital Monitor Operation Classification
Bit 1 2 3 4 ∼ 8
Japanese setting OFF OFF
Not used
English setting ON OFF
Chinese setting OFF ON
Test mode ON ON
Power must be turned off before changing setting.
Function Item
LCD monitor oper-
ation
Digital monitor
(F mode)
Remarks
Operation Mode
Screen
Mode − ○ F000 Dual, backup, etc.
Dual operation time ○
−
Switch conditions ○
Switch time ○
Backup pressure ○ Differential pressure
Unload ○ Differential pressure
Dual operation remaining time △ (AUTO change)
Speed control mode
−
○ (Factory set) V type only
Capacity Control
Screen
Type (Left: Capacity control) ○ F019 Example: I type (load/unload type)
Type (Center: Setting type) ○ F018 Example: Setting 1
Type (Right: Function) ○
−
Option (not supported)
Pressure loss ○ Option (not supported)
Total piping capacity ○ Option (not supported)
Control pressure
−
○ F022 ∼ Setting 1, Setting 2
Recovery pressure ○ F022 ∼ Setting 1, Setting 2
Target pressure ○ F022 ∼ Pressure differential
Time limit ○ (Factory set) Energy saving mode decision time
Setting 2: Use time ○
−
Scheduled Operation
Screen
Contents ○ Function switch
Start/stop time ○
Data measurement time ○ Operation data measurement
Other Settings Compressor No. setting
−
○ F001
Instantaneous power interruption (IPI) setting ○ F002 ∼
Remote operation setting ○ F005 ∼
Dryer operation setting ○ F008 ∼
AUTO operation setting ○ F011 ∼
Energy saving mode setting ○ Display switch button operation
Reset Shutdown/alarm reset ○ Reset button operation
Load count reset ○ Remote + display switch button
Maintenance reset ○ − Set button 7 sec. ON
Shutdown/alarm history clear − ○ F041
24
3. OPERATING THE DSP [How to Use the Liquid Crystal Display (LCD)]

27. 3.4 How to Use the Digital Monitor
3.4.1 How to display operation status, shutdown history, and status of various settings
All display contents of the digital monitor are linked with the LCD monitor. All of the following display contents can
be can be confirmed by the LCD monitor.
Use the following operations to display the contents of other operation/setting status on the LCD monitor and simply
confirm operation status and setting status by the digital monitor.
(1) How to Display the Operation Status
When the power is turned on, discharge pressure is displayed
on the screen of the digital monitor. Use the following proce-
dure to switch the digital monitor to other display.
① Press the SWITCH DISPLAY button. Operation time is
then displayed on the screen.
② Press the SWITCH DISPLAY button. Interstage pressure
is then displayed on the screen together with “b.”
③ Press the SWITCH DISPLAY button. Compressor dis-
charge temperature is then displayed on the screen togeth-
er with “C.”
④ Press the SWITCH DISPLAY button. Load rate is then dis-
played on the screen together with “L.”
⑤ Press the SWITCH DISPLAY button. Load count is then
displayed on the screen in units of 10,000 times together
with “U.”
Each time the SWITCH DISPLAY button is subsequently
pressed, it continues on to (2) Display of shutdown history
and (3) Monitor display of various settings. To return one
item at a time, press 2
. To return to discharge pres-
sure, press RESET.
● If the alarm or shutdown light is flashing, the shutdown
code is displayed along with “E0” ( page 35, 36).
“E0” indicates the contents of the latest shutdown.
● If the alarm or shutdown light is flashing, it indicates that
the alarm or shutdown has not been reset. Check E0.XX
and reset.
リセット
To shutdown history display
b ： Interstage pressure (MPa)
P：Discharge pressure (MPa)
Operation time (×10)
Flashes when operation time is added.
L ： Load rate（%）
U： Load count（×10,000 times）
H： Not used (display only)
表示切替 １
2
Press SWITCH DISPLAY.
d： Not used (display only)
C： Compressor discharge
temperature (°C)
（50℃）
Proceeds by 1 each
time pressed.
Returns by 1 each
time pressed.
Returns to discharge
pressure.
IMPORTANT
1. When other than P0.00 is displayed, automatically
returns to P0.00 discharge pressure display in 3 min-
utes.
2. Load rate is a reference value determined by com-
putation.
25
3. OPERATING THE DSP [How to Use the Digital Monitor]

28. SWITCH DISPLAY
Press 8 times.
[1 prior shutdown]
[Local shutdown]
［Oldest shutdown］
１
Discharge pressure display
History consists of 6 items.
Not used (display only)
To display of various settings
XX： Shutdown code
リセット
表示切替 １
2
Not used (display only)
Proceeds by 1 each
time pressed.
Returns by 1 each
time pressed.
Returns to discharge
pressure.
(2) How to Display Shutdown History
Use the following procedure to display shutdown history on
the screen.
① Press the SWITCH DISPLAY button 8 times. “E0.” is the
displayed together with the shutdown code ( page
35, 36). “0” indicates the latest shutdown. (Automatically
changes to “E.0” when shutdown or alarm occurs.)
② Press the SWITCH DISPLAY button. “E1.” is then dis-
played along with the shutdown code. “1” indicates shut-
down that occurred previously. Six items of data from 0 – 5
are recorded. “E5” indicates the oldest shutdown.
③ Press the RESET Button. The screen then returns to the
usual digital monitor display.
IMPORTANT
If the shutdown code “XX ”is “ ” it means there is no
shutdown history. Also, when anything other than shut-
down history is displayed without resetting shutdown,
it returns to the latest shutdown history in 3 minutes.
SWITCH DISPLAY
Press 16 times.
Discharge pressure display
A ： Capacity control type
No.0 ： Control status
No.1 ： Start pressure 1
070 ： 0.7MPa
No.2 ： Recover pressure 1
060 ： 0.6MPa
No.5 ： Start pressure 2
070 ： 0.7MPa
No.8 ： Instantaneous power
interruption (IPI) setting
000 ：
No.9 ： Compressor address
001 ： No.1
No.6 ： Recover pressure 2
060 ： 0.6MPa
No.7 ： Pressure differential 2
005 ： 0.05MPa
No.3 ： Pressure differential 1
005 ： 0.05MPa
リセット
１
表示切替 １
2
No.4 ： ECOMODE
［Energy conservation mode］
Decision time
Proceeds by 1
each time pressed.
Returns by 1 each
time pressed.
Returns to
discharge pressure.
Invalid
(3) How to Display Various Settings (Perform operation only when confirmation is
necessary.)
Use the following procedure to display capacity control type
and pressure setting values for confirmation.
① Press the SWITCH DISPLAY button 16 times. “0.A ＊＊ ”
is then displayed on the screen. ＊＊ changes with specifi-
cations. “A” may be “L” or “U” depending on capacity con-
trol specifications.
② Consists of items 0 - 9. Pressure setting status and
optional pressure setting 2 can be confirmed each time the
SWITCH DISPLAY button is pressed.
③ Press the RESET Button. The screen then returns to the
usual discharge pressure display.
IMPORTANT
Symbol displayed at No. 0 and corresponding capacity
control type
A: AUTO function setting
L: Fixed speed type setting
(INTE … Load/unload operation)
U: V type AUTO function off setting
For details on the various types, see pages 22 and 64 - 68.
26
3. OPERATING THE DSP [How to Use the Digital Monitor]

29. 3.4.2 How to Set Control Functions
■ Various settings (instantaneous power interruption (IPI), remote operation, capacity control
setting, pressure setting, etc.)
Switches display from monitor mode to setting mode (F mode).
１
１ 2
１
2
リセット
表示切替
For details, see the F mode table.
To alter settings, change the values with the
buttons. ( page 28)
Displays 000th
item of F mode.
Changes each time FUNCTION is pressed.
Forward
Back
Press ENTER to enter the settings.
Back
Press and hold
simultaneously for at
least 3 seconds.
Perform same
operation to return.
Displays setting contents.
F000：（0：Sets single unit operation.）
F000：（1： Sets multiple unit control.）
27
3. OPERATING THE DSP [How to Use the Digital Monitor]

30. Settings can be altered or entered into the memory from the digital monitor without opening the start panel.
Function
7 segment
display
Item Range
Precision/
unit
Initial value
Multiple unit control setting F000 Control setting 0∼1 1 0
0：Single operation, 1: Multiple unit
control (communication supported)
Instantaneous power inter-
ruption (IPI) restart setting
F002
Instantaneous power inter-
ruption (IPI) setting
0∼1 1 0 0：ON、1：OFF
Remote operation set-
ting
F005
Remote control switch
method
0∼3 1 0
0：Panel setting, 1：Local fixed,
2：Remote fixed,
3：Remote switch signal
F006 Remote operation method 0∼1 1 0 0：Pulse input, 1：Level input
F007
Remote operation shut-
down recovery
0∼1 1 0 0：Disable, 1：Enable
AUTO setting (*2) F011 AUTO operation enable 0∼1 1 0 0：Enable, 1：Disable
Capacity control F018 Control pressure selection 0∼2 1 0
0：Setting 1, 1：Setting 2,
2：External input
Function setting
(optional)
F021 Pressure control mode 0∼2 1 0
0：Built-in sensor, 1：External contact,
2：External input
0.7/0.93MPaspecifications
V type
Pressure
setting 1
※
F022
Control pressure setting 1
(control pressure)
0.5∼0.70 0.01MPa 0.70（0.93）
※ Setting can be altered at any time.
F023
Start pressure 1
(cut out pressure)
0.5∼0.72（0.95） 0.01MPa 0.72（0.95）
F024
Recovery pressure 1
(cut in pressure)
0.5∼0.68（0.91） 0.01MPa 0.67（0.90）
F025（＊2）
P type recovery pressure 1
(restart pressure)
0.5∼0.68（0.91） 0.01MPa 0.67（0.90）
Pressure
setting 2
※
F031
Control pressure setting 2
(control pressure)
0.5∼0.70 0.01MPa 0.70（0.93）
F032
Start pressure 2
(cut out pressure)
0.5∼0.72（0.95） 0.01MPa 0.72（0.95）
F033
Recovery pressure 2
(cut in pressure)
0.5∼0.68（0.91） 0.01MPa 0.67（0.90）
F034（＊2）
P type recovery pressure 2
(restart pressure)
0.5∼0.68（0.91） 0.01MPa 0.67（0.90）
Standard
type
Pressure
setting 1
※
F023
Start pressure 1
(cut out pressure)
0.5∼0.70（0.93） 0.01MPa 0.70（0.93）
※ Setting can be altered at any time.
F024
Recovery pressure 1
(cut in pressure)
0.5∼0.60（0.92） 0.01MPa 0.60（0.83）
Pressure
setting 2
※
F032
Start pressure 2
(cut out pressure)
0.5∼0.70（0.93） 0.01MPa 0.70（0.93）
F033
Recovery pressure 2
(cut in pressure)
0.5∼0.60（0.92） 0.01MPa 0.60（0.83）
Shutdown history clear F041（＊1）History clear 0 ∼1 1 0 0：Enter, 1：History clear
Note:
※ Setting can be altered at any time other than this.
＊1：When set to 1,” history is cleared. After clearing, the value is automatically reset to “0.”
＊2：Only the V type is equipped with AUTO function. The AUTO function is available as an option for the Fixed speed type.
Do not alter settings for any F items not given in the table.
IMPORTANT
1. Pressure setting
V type: Set pressure differential of start pressure and recovery pressure to a minimum of 0.05 MPa when using a standard
receiver. Set Pressure differential of start pressure and control pressure to a minimum of 0.02 MPa.
Fixed speed type: Set pressure differential of start pressure and recovery pressure to a minimum of 0.1 MPa.
2. Function for switching to pressure setting 2 by external pressure alteration input is optional.
28
3. OPERATING THE DSP [How to Use the Digital Monitor]

31. 3.4.3 Alteration of Pressure Setting Values
Use the following procedure to alter the pressure set-
ting values for the capacity control system.
① Switch from monitor mode to setting mode (F
mode).
② Set PRESSURE SETTING 1 of F mode.
(For detailed contents of setting specifications, see
page 28.)
If using pressure setting 2, you must also set pres-
sure setting 2.
For operation method, be sure to refer to the vari-
ous settings, and after entering the setting values
with the STORE button, return to the monitor
mode.
１
2
機能
記憶
Pressure
setting 1
Alter
values.
Press button.
Press button.
3.4.4 Capacity Control Mode Setting and Confirmation
機能
記憶
１
2
AUTO setting
Alter
values.
(Initial value 0)
Press button.
Press button.
Set to AUTO OFF.
IMPORTANT
The AUTO function is available for the Fixed speed type
as an option.
You can switch the capacity control mode by the follow-
ing method according to the application. The V type is a
automatic stop type, but can also be changed to control
mode that does not stop automatically (AUTO OFF).
Capacity control mode setting can be changed by
switching the digital monitor from monitor mode to
setting mode (F mode) while the compressor is not
running and setting to “0: Enable” or “1: Disable” by
altering the AUTO setting (F011) of F mode.
Capacity control mode AUTO ON AUTO OFF
F011 0 : Enable 1 : Disable
Digital monitor display 0．A Ｘ X 0．U Ｘ X
After altering, confirm the capacity control mode by
display of various settings on the digital monitor (
page 25).
（ For capacity control operation and details, see
pages 31 and 64 - 68. Pressure for control can also
be switched by F018 (pressure setting 1 / pres-
sure setting 2).
29
3. OPERATING THE DSP [How to Use the Digital Monitor]

32. 3.4.5 Remote Operation Setting
ＲＥＭＯＴＥ
遠 方
On
On
Flashing
Off
(1) Remote setting by instrument panel
(2) Remote setting fixed
(3) Remote setting by external operation button
Local setting
機能
記憶
１
2
Alter
values.
(Initial value 1)
Remote
operation
switch
method
Press button.
Press button.
Set to remote fixed.
Operation mode is basically switched by panel opera-
tion. The remote operation mode can also be set by
methods (2) and (3).
① Turn off the main power supply.
② Remove the front cover and remove the start panel
cover.
③ Connect the wiring of the remote control panel and
the compressor control panel.
( See the wiring diagrams on pages 52 - 56.)
④ Mount the start panel cover and the front cover.
⑤ Turn on the main power supply.
[1] To “set the operation buttons of the instrument
panel to remote operation mode”
① Press the REMOTE button.
② The REMOTE light lights to indicate that operation
of the instrument panel buttons is set to the remote
operation mode.
③ To return to local operation mode, press the
REMOTE button again. The REMOTE light then
goes off to indicate that operation has been switched
to the local operation mode.
[2] To “fix remote operation to remote operation mode”
① Switch from the monitor mode to the setting mode
(F mode).
② Change the remote operation switch method for
remote operation setting (F005) from “0: Panel set-
ting” to “2: Remote fixed.”
③ The REMOTE light lights to indicate that the remote
operation mode has been set.
[3] To “set to remote operation by operation button
provided externally”
(Consult with your dealer or the Hitachi Service
Station.)
① Wire the external remote setting buttons.
② Switch from the monitor mode to the setting mode
(F mode).
③ Change the remote operation switch method for
remote operation setting (F005) from “0: Panel set-
ting” to “3: Remote switch signal.”
④ Set the external remote setting button to “ON.”
⑤ The REMOTE light flashes to indicate that the oper-
ation mode has been switched to remote operation
by external buttons.
IMPORTANT
● In the case of multiple unit control specifications, when
multiple unit control is set, it automatically changes to
the remote setting. The REMOTE light flashes at this
time.
● Remote operation method alteration in the setting
mode can only be entered when the compressor is not
operating.
● The compressor STOP button can also be used to stop
operation when operating in the remote mode.
30
3. OPERATING THE DSP [How to Use the Digital Monitor]

33. 3.4.7 Capacity Control Flow when ECOMODE (Energy Saving Mode) is Set
(ECOMODE is set to off when shipped from the factory, but may be set according to your needs.)
ＲＵＮＮＩＮＧ ＣＯＮＴＲＯＬ
運転管理
ＡＬＡＲＭ
警 報
１
記 憶
遠 方
ＲＥＭＯＴＥ
表示切替／
ワイドモード
ＳＴＲ
機 能
ＦＵＮＣ
リセット
ＲＥＳＥＴ
ＳＥＬＥＣＴ／ＷＩＤＥ
１
表示切替／
ワイドモード
ON ：Light flashes.
OFF：Light goes off.
ＳＥＬＥＣＴ／ＷＩＤＥ
表示切替／ワイドモード
Set by button
Execute capacity control in accordance with the follow-
ing time charts.
(1) ECOMODE (Energy Saving Mode) setting
When you set to ECOMODE by load/unload type
control, if the cycle time for load → unload exceeds
30 seconds, the start pressure setting is automati-
cally lowered until it reaches recovery pressure +
0.05 MPa to conserve energy.
If 30 seconds is exceeded, the DISPLAY SWITCH
/ WIDE MODE light flashes; if 30 seconds is not
exceeded, the DISPLAY SWITCH / WIDE MODE
light lights steadily, and control is executed by pres-
sure setting value of ordinary load/unload type con-
trol.
When using ECOMODE (Energy Conservation
Mode), “ECO” is displayed on the monitor screen.
( page 16)
(2) Precautions when using ECOMODE (Energy
Saving Mode)
Enabling ECOMODE (Energy Conservation Mode)
requires an air tank that is one turn larger that the
air tank recommended for load/unload type control.
( For information concerning the air tank, see
page 42.)
This function is used for load/unload type control,
and operates only for the ordinary pressure setting.
Linepressure
Energy Saving Effect
Load Unload
Time
Start pressure
(Unload start pressure)
Recovery pressure
(Loadrecoverypressure)
Recovery is
automatically
reduced.
: 0.1MPa
: 0.05MPa
Factory set upper/lower limit pressure differential
ECOMODE differential pressure
Start pressure is automatically reduced to 1 cycle per 30 seconds.
※ Start pressure = Cutout pressure
※ Recovery pressure = Cutin pressure
According to alteration of the pressure setting value of
section 3.4.1, by setting start pressure 2 (value of F032)
and recovery pressure 2 (value of F033), the control
setting can be easily switched by external button opera-
tion in accordance with usage time on the load side.
During ordinary control, the LOAD light is lit when
loading and goes off when unloading. With pressure
setting 2, however, the light flashes when loading and
goes off when unloading.
If using this function, consult with your dealer or the
Hitachi Service Station. (The ECOMODE however can-
not be used with pressure setting 2.)
Pressure setting 2 selection (flash range)Ordinary (on range)
ONOFFExternal pressure setting switch
Time
Energy Saving Effect
Load Unload
Start
pressure 2
Recovery
pressure 2
Start
pressure 1
Recovery
pressure 1
Linepressure
Load light
※ Start pressure = Cutout pressure
※ Recovery pressure = Cutin pressure
31
3. OPERATING THE DSP [How to Use the Digital Monitor]
3.4.6 Pressure Setting Switch Function
(Can be supported as an option)

34. CAUTION
3.5 Daily Operation
① Turn on the main power supply.
② Check the POWER light and LCD monitor display.
– Is the light lit ?
– Is the monitor screen displayed on the LCD monitor?
③ Check the level of lubricating oil.
– Is the oil level near the red line ?
④ Set the water drainage cock valve of the cooling
water piping and the water drainage cock on the
rear of the compressor to “fully closed.”
⑤ Allow cooling water to pass through.
① Open the discharge side valve.
② Start operation by pressing the START button.
③ Check the pressure after the compressor starts up.
– The compressor stops running if the oil pressure does not
rise to at least 0.08 MPa.
– The compressor switches to full load operation within 15
seconds for the Fixed speed type and within 10 seconds for
the V type.
④ Make sure the discharge pressure rises gradually.
– Make sure the maximum pressure does not exceed the
specified discharge pressure.
● When using the DSP air compressor, do not raise the discharge pressure excessively. Operating the
DSP air compressor over the rated pressure can result in main motor overload, shutdown of the air-
end and/or damage of parts.
● If the safety relief valve has blown or a protective device has shutdown the DSP air compressor,
investigate the cause of and take corrective action. If there any questions or comments in taking these
actions, please contact the local Hitachi distributor.
③
ＲＵＮＮＩＮＧ ＣＯＮＴＲＯＬ
運転管理
ＲＵＮＮＩＮＧ ＭＯＤＥ
ＡＬＡＲＭ
警 報
運転状況
故 障
ＬＯＡＤ
ＳＨＵＴＤＯＷＮ
ＲＥＭＯＴＥ
負 荷
遠 方
電 源
ＰＯＷＥＲ
起動待ち
ＡＵＴＯ ＳＴＡＲＴ
停 止
ＳＴＯＰ
運 転
ＳＴＡＲＴ
１ ２
記 憶
遠 方
ＲＥＭＯＴＥ
表示切替／
ワイドモード
ＳＴＲ
機 能
ＦＵＮＣ
リセット
ＲＥＳＥＴ
ＳＥＬＥＣＴ／ＷＩＤＥ
②
UNLOAD STOP
3.5.1 Preparing the DSP Air Compressor
Water-Cooled
DIS. PRESS： ０．７０ＭＰａ
INTSTG. P： ０．１５ＭＰａ
OIL PRESS： ０．１５ＭＰａ
CLT PRESS： ＊．＊＊ＭＰａ
[Rear View]
②
③④
①
ＲＵＮＮＩＮＧ ＣＯＮＴＲＯＬ
運転管理
ＲＵＮＮＩＮＧ ＭＯＤＥ
ＡＬＡＲＭ
警 報
運転状況
故 障
ＬＯＡＤ
ＳＨＵＴＤＯＷＮ
ＲＥＭＯＴＥ
負 荷
遠 方
電 源
ＰＯＷＥＲ
起動待ち
ＡＵＴＯ ＳＴＡＲＴ
停 止
ＳＴＯＰ
運 転
ＳＴＡＲＴ
１ ２
記 憶
遠 方
ＲＥＭＯＴＥ
表示切替／
ワイドモード
ＳＴＲ
機 能
ＦＵＮＣ
リセット
ＲＥＳＥＴ
ＳＥＬＥＣＴ／ＷＩＤＥ
UNLOAD STOP
3.5.2 Starting the DSP Air Compressor
Make sure the oil level of the lubricating oil is between
the red lines while the compressor is running. Because
lubricating oil is circulated through the cooler and the pip-
ing while the compressor is running, the position when
the compressor is running and when it is off differs, and is
higher when the compressor is not running.
IMPORTANT
32
3. OPERATING THE DSP [Daily Operation]

35. ① Check the LCD for operating pressures and tem-
peratures, and verify that:
– Discharge air pressure, interstage air pressure, oil pres-
sure, discharge air temperature, 2nd-stage suction air tem-
perature, and oil temperature stay within a normal range;
see page 47
② Make sure air containing drain from the inter cooler
drain discharge port and after cooler drain dis-
charge port is intermittently discharged.
① Press the UNLOAD STOP button. The compressor
then unloads for 5 minutes and then stops running.
(In the case of an emergency, press the STOP but-
ton.)
② Check the LCD for pressures, and verify that:
- Oil pressure, interstage air pressure, 0 MPa (or 0.01 MPa
depending on your operating conditions).
③ Drain the condensate through the control line filter’s
condensate drain valve.（Fixed speed type）
④ Close the discharge stop valve.
⑤ Stop the cooling water. Open the valve for drain-
ing water in the cooling water piping and drain the
cooling water. To avoid damaging the casing and
cooler, be careful not to allow freezing during the
winter.
モニタ
メニュー
リセット
遠 方
機 能
電 源
運 転 停 止
運転状況
故 障
運転管理
負 荷
遠 方
起動待ち
設 定
自 動
UP/
DOWN
警 報
記 憶
表示切替/
ワイドモード
＋／−
AUTO
MONITOR
MENU
SET
SELECT/WIDE
2
RUNNING CONTROL
STARTREMOTE
1
FUNC
［× 10h］
ALARM
STR
REMOTE
RUNNING MODE
AUTO START
POWER
LOAD
RESET
SHUTDOWN
STOP
MONITOR
UNLOAD STOP
[Rear View]
②
④
③
ＲＵＮＮＩＮＧ ＣＯＮＴＲＯＬ
運転管理
ＲＵＮＮＩＮＧ ＭＯＤＥ
ＡＬＡＲＭ
警 報
運転状況
故 障
ＬＯＡＤ
ＳＨＵＴＤＯＷＮ
ＲＥＭＯＴＥ
負 荷
遠 方
電 源
ＰＯＷＥＲ
起動待ち
ＡＵＴＯ ＳＴＡＲＴ
停 止
ＳＴＯＰ
運 転
ＳＴＡＲＴ
１ ２
記 憶
遠 方
ＲＥＭＯＴＥ
表示切替／
ワイドモード
ＳＴＲ
機 能
ＦＵＮＣ
リセット
ＲＥＳＥＴ
ＳＥＬＥＣＴ／ＷＩＤＥ
UNLOAD STOP
①
DIS. PRESS： ０．７０ＭＰａ
INTSTG. P： ０．１５ＭＰａ
OIL PRESS： ０．１５ＭＰａ
CLT PRESS： ＊．＊＊ＭＰａ
3.5.3 During Operating the DSP Air Compressor
3.5.4 Stopping the DSP Air Compressor
Water-Cooled
33
3. OPERATING THE DSP [Daily Operation]

36. 3.6 Oil Mist Remover Daily Operation
3.6.1 When Starting
3.6.2 When Stopping
① Make sure that the vacuum indicator shows a red
mark.
② Verify that the pressure gauge reads 0 (zero).
φ8
Make sure that the pressure
gauge reads as follows:
Pressure Gauge
0.35 to 0.38 MPa
Make sure that the
condensate is not
collected in the
filter bowl.
If the condensate is
collected, push up
the cock to drain
the condensate.
Make sure that the vacuum
indicator does not show a
red mark.
Condensate Drain Cock
If the oil pressure is reduced to 0.08 MPa or lower, the oil pres-
sure sensor will detect it and shut down the DSP air compressor.
① Use the relief valve to regulate the oil pressure. To
regulate the oil pressure, open the relief valve cap,
loosen the lock nut, and turn the regulating bolt to
keep the oil pressure at the specified 0.12 to 0.16MPa.
・0.12 to 0.16 when the ambient temperature is 20
degree C or higher.
・0.14 to 0.18 when the ambient temperature is 20
degree C or lower.
(for V type, adjust at the maximum operating frequency.)
② Turn the regulating bolt clockwise to increase the
oil pressure and vice versa.
③ Tighten the locknut and replace the cap.
IMPORTANT
Relief Valve
3.7 Adjusting the DSP
3.7.2 Regulating the Oil Pressure
Locknut
Seal Washer
Air Intake Filter
Usually keep the bolt
tightened, but not
excessively.
Adjusting Bolt
(Suction Bypass Valve)
Suction
Throttle
Valve
①④
②④
③
② The first steps to resolve the lower suction vacuum
pressure are as following.
A) Clean or replace the air intake filter.
B) Clean the suction throttle valve’s valve plate.
Note; If the unloaded interstage pressure drops as
low as -0.08MPa, discharge air temperature
will gradually increased.
③ If the DSP air compressor cannot be shutdown to
clean these parts, turn the adjusting bolt (the suction
bypass valve) counterclockwise to open. This will
allow the air intake and increase the discharge air
pressure to be geater than -0.08MPa when running
unloaded.
④ Replace the consumable parts in the air intake fil-
ter and suction throttle valve with new consumable
parts in accordance with the appropriate mainte-
nance schedule. For the detail refer to the sec-
tion 9, Maintenance the DSP.
① When dust particles accumulate on the valve plate of
the suction throttle valve, the suction vacuum pres-
sure may drop and eventually causing the discharge
air temperature to rise.
3.7.1 While Operating the DSP Air Compressor
(Fixed speed type)
The interstage pressure of as low as -0.08 MPa during
unloading period may increase the discharge air temperature.
IMPORTANT
34
3. OPERATING THE DSP [Oil Mist Remover Daily Operation, Adjusting the DSP]

37. 4.1 Protective Devices
CAUTION
If an alarming trouble or a shutdown trouble has happened, investigate the cause and take a corrective
remedy before restarting.
If you have anything unclear or any question, please contact the local Hitachi distributor.
The DSP is provided with the protective devices as listed below. Shutdown troubles and alarming troubles detected by
these protective devices are indicated on the liquid crystal display (LCD). Referring to the LCD indications, investigate
the cause of a shutdown or alarming trouble.
■ When Connecting the power
LCD Indication What and
How to Detect
SHUTDOWN
MODELight
Detector Shutdown What Actions to Take
How to
Reset
History
CodeHeading Trouble Description
PROBREM
Reversal phase connection
Detected for 3 seconds after
connecting the power
Blinks
in red
CPU Yes Change 2 of 3 wires of the power cord. Press RESET
button. 01
Phase-lacking connection CPU Yes
Reconnect the power cord tightly, check the
power supply, and take a corrective remedy.
Press RESET
button.
02
Short period Power Interruption Black out for 1 to 5 seconds
−
CPU No See page for Power Interruption detection
−
03
Instantaneous Power Interruption Black out for less than 1 seconds CPU No See page for Power Interruption detection 04
■ During Operation
LCD Indication What and
How to Detect
SHUTDOWN
MODELight
Detector Shutdown What Actions to Take
How to
Reset
History
CodeHeading Trouble Description
SHUTDOWN
Discharge air tem-
perature (1)
[Fixed speed type]
The temperature detected
at 1st stage rises above
the below settings. Blinks
in red
Thermistor Yes See page 37.
Press RESET
button.
55
0.70MPa model about 225℃
（about 215℃）0.93MPa model
Discharge air temperature (1)
The temperature detected
at 1st stage rises above
the below settings. Blinks
in red
Thermistor Yes See page 37.
Press RESET
button.
55
0.70MPa model about 230℃
（about 220℃）0.93MPa model
Discharge air tem-
perature (2)
The temperature detected
at 1st stage rises above
the below settings.
Blinks
in red
Thermistor Yes See page 37.
Press RESET
button.
560.70MPa model
about 230℃
（about 220℃）
0.93MPa model
about 260℃
（about 250℃）
Interstage pressure
[Fixed speed type]
0.27MPa or higher
Blinks
in red
Pressure sensor Yes See page 37.
Press RESET
button.
52
Interstage pressure
0.30MPa or higher
Blinks
in red
Pressure sensor Yes See page 37.
Press RESET
button.
52
2nd-stage suction air
temperature
73(70)℃ or higher
(after the intercooler)
Blinks
in red
Thermistor Yes See page 37.
Press RESET
button.
5B
Oil temperature 73(70)℃ or higher
Blinks
in red
Thermistor Yes See page 37.
Press RESET
button.
58
Oil pressure
[Fixed speed type]
0.08MPa or lower
Blinks
in red
Pressure sensor Yes See page 37.
Press RESET
button.
5C
Oil pressure
(OIL-LOW PRESS)
Oil pressure descends
under below settings. Blinks
in red
Pressure sensor Yes See page 37.
Press RESET
button.
5CFreg. 45Hz or higher 0.08MPa
Freg. less than 45Hz 0.04MPa
Overloading
(main motor)
Detected during oper-
ation
Blinks
in red
Thermal relay Yes See page 37.
Press RESET
button.
17
Overloading
(ancillary motor)
Detected during oper-
ation
Blinks
in red
Thermal relay Yes See page 37.
Press RESET
button.
53
Answer error of 52
Detected during
running.
Blinks
in red
CPU Yes See page 37.
Press RESET
button.
51
Answer error of 42
[Fixed speed type]
Detected after shifting
to △ running.
Blinks
in red
CPU Yes See page 37.
Press RESET
button.
16
FAILURE
INV STOP
Inverter tripping or main
motor overloading with
automatic retrials.
Failure signal from
inverter
Blinks
in red
CPU
Failure
stop after
repetition
of retrials.
See page 37.
Press RESET
button.
44
35
4. TROUBLESHOOTING

38. ■ Others
LCD Indication What and
How to Detect
SHUTDOWN
MODELight
Detector Shutdown What Actions to Take
How to
Reset
History
CodeHeading Trouble Description
PROBLEM
Battery out Battery voltage low
Blinks
in green
CPU No
Disconnect the power, and replace the
battery with a new one.
Press RESET
button.
64
Error of a scheduling
operation
Start/stop time not set
yet
Blinks
in green
CPU No Check the operation setting.
Press RESET
button.
62
Error of a multiple-
unit operation
Setting error
Blinks
in green
CPU No
Check the wire and the operation
setting.
Press RESET
button.
5B
Error of RS−485C
port
Setting error
Blinks
in red
Thermistor Yes
Check the wire and the operation
setting.
Press RESET
button.
63 65
∼68
Error of RS−485
port
Setting error
Blinks
in green
Pressure sensor Yes
Check the wire and the operation
setting.
Press RESET
button.
63 65
∼68
FAILURE
PCB error
(ROM1) (RAM1)
MAIN Memory failed
Blinks
in red
CPU Yes
Disconnect and reconnect the power. If the
problem is reproduced, change the PCB.
Press RESET
button.
41
42, 46
(ROM2) (RAM2)
LCD Memory failed
Blinks
in red
CPU Yes
Disconnect and reconnect the power. If the
problem is reproduced, change the PCB.
Press RESET
button.
41
47, 48
CT error Disconnected
Blinks
in red
CPU Yes
Disconnect the power and check the
CT sensor wire for tightness.
Press RESET
button.
E10
Pressure sensor
(disconnection 1)
PS5 disconnected (sensor
for interstage pressure)
Blinks
in red
CPU Yes
Disconnect the power and check the
pressure sensor wire for tightness.
Press RESET
button.
33
Pressure sensor
(disconnection 2)
PS2 disconnected (sensor
for discharge air pressure)
Blinks
in red
CPU Yes
Press RESET
button.
34
Pressure sensor
(disconnection 4)
PS4 disconnected (sensor
for Oil pressure)
Blinks
in red
CPU Yes
Press RESET
button.
39
Temperature sensor
(disconnection 2)
TH2 disconnected (thermistor
for interstage temperature)
Blinks
in red
CPU Yes
Press RESET
button.
32
Temperature sensor
(disconnection 3)
TH3 disconnected (thermistor for
1st-stage discharge temperature)
Blinks
in red
CPU Yes
Disconnect the power and check the
thermistor sensor wire for tightness.
Press RESET
button.
35
Temperature sensor
(disconnection 4)
TH4 disconnected (thermistor for
2nd-stage discharge temperature)
Blinks
in red
CPU Yes
Press RESET
button.
36
Temperature sensor
(disconnection 5)
TH5 disconnected
(thermistor for oil temperature)
Blinks
in red
CPU Yes
Press RESET
button.
37
NOTES:
1. Figures in ( ) are for water cooled models.
2. Both the DSP for a 400 V class power supply and the DSP with a control circuit of 100 volt employ a reversal phase relay.
3. Both the DSP for a 400 V class power supply and the DSP with a control circuit of 100 volt indicate a phase-lacking connection as a reversal phase.
4. Battery Replacement:
Use the Hitachi Maxell Button type Lithium Battery (model：CR2032WK17, with lead wire connector, 3V)
Replace the battery with a new one every 6 years. When replacing, disconnect the power and complete the replacement work within 15 minutes.
5. If a Thermistor is disconnected, an override operation is not allowed. Contact your distributor immediately.
■ During Operation
LCD Indication What and
How to Detect
SHUTDOWN
MODELight
Detector Shutdown What Actions to Take
How to
Reset
History
CodeHeading Trouble Description
ALARM
Clogging of air
intake filter
Pressure differential
of −4.98kPa or more
Blinks
in green
Pressure
differential
sensor
No See page 76
Press RESET
button.
21
Discharge air
temperature (1)
[Fixed speed type]
The temperature detected at 1st
stage rises above the below settings. Blinks
in green
Thermistor No See page 37
Automatically
reset.
250.70MPa model about 220℃
（about 210℃）0.93MPa model
Discharge air temperature (1)
The temperature detected at 1st
stage rises above the below settings. Blinks
in green
Thermistor No See page 37
Automatically
reset.
250.70MPa model about 225℃
（about 215℃）0.93MPa model
Discharge air
temperature (2)
The temperature detected at 2nd
stage rises above the below settings.
Blinks
in green
Thermistor No See page 37
Automatically
reset.
260.70MPa model
about 225℃
（about 215℃）
0.93MPa model
about 255℃
（about 245℃）
2nd-stage suction air
temperature
68(65)℃ or higher
(after the intercooler)
Blinks
in green
Thermistor No See page 37
Automatically
reset.
2B
Oil temperature 68(65)℃ or higher
Blinks
in green
Thermistor No See page 37
Automatically
reset.
26
L. COUNT OVER
(Load/unload cycle
count)
1 million times
Blinks
in green
CPU No
Replace suction throttle valve consum-
able parts and Blow off solenoid valves
Hold the REMOTE
Button and SELECT/
WIDE Button for
at lease 7 seconds
59
36
4. TROUBLESHOOTING [Protective Devices]

39. 4.2 Troubleshooting the Air Compressor4.2 Troubleshooting the Air Compressor
Most likely problems, causes, and remedies are described below.
Causes LCD Indication Causes Corrective Remedies
The DSP motor
does not start. ＜ P R O B L E M ＞
C O N N E C T I O N E R R ： R E V
P r e s s R E S a f t e r C H K .
1. Power supply switch - Off
2. Power - Failed
3. Power cord - In a reversal phase
connection
4. Power cord - In a phase-lacking
connection
1. Check the main breaker.
2. Check the power supply.
3. Change 2 of 3 wires of the power
cord.
4. Reconnect the power cord tightly and
check the power supply.
NOTE: Phase-lacking is detectable only
when connecting the power.
＜ P R O B L E M ＞
C O N N E C T I O N E R R ： O P E N
P r e s s R E S a f t e r C H K .
Shutdown –
1st-stage discharge
air temperature and/
or pressure too high
＜ A L A R M ＞
D I S . T E M P . 1 ：
P r e s s R E S a f t e r C H K .
1. 2nd-stage AIR END air intake effi-
ciency - Lowered
2. Air intake filter - Dirty
3. Temperature of Suction Air-High
1. Contact your Hitachi distributor.
2. Clean the air intake filter.
3. Lower the suction air temperature.
＜ S H U T D O W N ＞
H I G H D I S . T E M P ：
P r e s s R E S a f t e r C H K .
Shutdown –
2nd-stage discharge
air temperature too
high
＜ A L A R M ＞
D I S . T E M P . 2 ：
P r e s s R E S a f t e r C H K .
1. Check valve – Compressed air
leaked (from the aftercooler to the
air end when the DSP unloads)
2. Suction throttle valve - Dirty
[Fixed speed type]
1. Replace the check valve.
2. Clean the Suction throttle valve.
[Fixed speed type]
Note: For information about the Suction
bypass valve, see page 29.
Shutdown –
2nd-stage suction air
temperature too high
＜ S H U T D O W N ＞
2 N D S U C T . T E M P ：
P r e s s R E S a f t e r C H K .
1. Cooling water pump – Failed, or
Cooling water pressure – Fluctuating
2. Intercooler – Dirty
1. Check the cooling water system.
2. Clean the intercooler
Shutdown –
Oil temperature too high ＜ S H U T D O W N ＞
O I L ： H I G H T E M P
P r e s s R E S a f t e r C H K .
1. Oil cooler – Dirty
2. Room temperature – High
3. Oil temperature control valve –
Failed
1. Check the oil cooler.
2. Reduce the room temperature.
3. Check the oil temperature control valve.
Shutdown –
Oil pressure too low ＜ S H U T D O W N ＞
O I L ： L O W T E M P
P r e s s R E S a f t e r C H K .
1. Oil strainer and/or oil filter – Dirty
2. Oil level – Low
1. Clean the oil strainer
2. Replace the oil filter.
3. Add the oil.
Shutdown –
Main motor and/
or ancillary motor
overloading
＜ S H U T D O W N ＞
O V E R L O A D ： M A I N
P r e s s R E S a f t e r C H K .
1. Power supply voltage – Low
2. Discharge air pressure – Too high
1. Rectify the power supply voltage.
2. Check the suction throttle valve
[Fixed speed type]
3. Check the capacity control system.
＜ S H U T D O W N ＞
O V E R L O A D ： S U B
P r e s s R E S a f t e r C H K .
1. Power supply voltage – Low
2. Cooling fan motor – Failed
1. Rectify the power supply voltage.
2. Check the cooling fan motor.
(Measure insulation resistance etc.)
Shutdown –
Inverter tripping/
restarting
＜ F A I L U R E ＞
S Y S T E M R E T R Y ：
1. Power supply voltage – Low or in unbalance
2. Discharge air pressure – Too high
3. Main motor – Overloading
NOTE: ‘INVERTER RESTART’ means that the DSP
shutdowns when the inverter repeats a
restarting action within 1 minute.
1. Rectify the power supply voltage.
2. Check the capacity control system.
3. Measure insulation resistance etc. or
check the main motor.
37
4. TROUBLESHOOTING [Troubleshooting the Air Compressor]

40. 4.3 Troubleshooting the Oil Mist Remover
① The vacuum indicator shows a red mark (Gear case has a positive internal pressure)
The pressure gauges reads zero (0) MPa. Check the solenoid valve for operation.
Pressure setting of the regulator is lower ?
Reset the regulator to a proper pressure.
Clean the filter.
Pressure of a control air is lower than 0.39 MPa ? Maintain the pressure of a control air at 0.39 MPa or more.
The gear case or gear case vent pipe has a leak
(for example, the oil filling port plug on the gear case is not tight).
･ Tighten every screw and plug to remove all leaks.
･ Make sure that the safety relief valve is closed.
Element may be dirty.
Inspect the element and replace if necessary.
② The safety relief valve has opened and oil mists are vented (the gear case internal pressure has risen).
See the NOTE below.
Yes
Yes
Yes
Yes
No
No
No
No
The safety relief valve is dirty or stuck open by a foreign
object.
Disassemble and clean the safety relief valve.
Replace if necessary.
Go to the procedure ① . The vacuum indicator shows a
red mark. (Gear case has a positive internal pressure.)
Yes
No
④ Oil pressure is low (oil pump may be inhaling air).
Accumulated oil is visible in the tube between the ele-
ment housing and the float trap.
Clean the nozzle of the float trap.
Upper or lower packing is not seated properly on the
element ?
Reinstall the element, seating the packing properly for a
maximum sealing performance.
Control air contains oil ? Check the control air for oil contents.
Element may be dirty.
Inspect the element and replace if necessary.
Yes
Yes
Yes
No
Has the air compressor developed an alarm or shutdown
trouble (i.e. oil filter dirty, oil pressure reduced due to oil
leaking, oil pump failed, safety relief valve failed, etc.)?
Readjust or repair as required.
The nozzle of the float trap is clogged (for example, a
large quantity of air is inhaled through the oil recovery
pipe to the oil pump inlet)?
Clean the nozzle of the float trap. Disassemble the float
trap and clean.
Yes
Yes
No
No
No
38
4. TROUBLESHOOTING [Troubleshooting the Oil Mist Remover]
③ Oil is vented through the ejector’s compressed air outlet (the separated oil is not being recovered).
NOTE:
The oil mist remover makes the gear case internal pressure negative during operation, reducing the pressure by 0.005 to 0.01
MPa . This is not unusual; reset the oil pressure on the safety relief valve.
NOTE:
The safety relief valve opens immediately when starting the DSP (the control air pressure is still low) or when the DSP has
stopped. This is a normal occurrence.

41. Common Base
Fork Slot Cover
Bolt (M6×15)
Pad
Use a pad to protect
the DSP enclosure
panels.
Use the adhesive tapes
to prevent the front door
from detached during
conveyance.
Use a pad to protect
the DSP enclosure
panels.
Use the adhesive tapes
to prevent the front door
from detached during
conveyance.
Keep the distance of
1500 mm or more.
Use the strong wires.
Adjust the wire length to
keep the DSP’s balance
when hoisting it.
Lift the unit balanced.
Use the attached
tie frame.
5.1 Unpacking the DSP Air Compressor
■ After unpacking the crate, verify that the inside DSP is what you have ordered, by referring to page 81 through 82
STANDARD SPECIFICATIONS”and also by checking the model nameplate.
■ Verify that the DSP is not damaged or deformed in transportation.
Model Nameplate Standard Accessories
Motor Output（kW）
Model
Frequency（Hz）
Foundation Bracket, Foundation Bolt/Nut（M20） 4 pieces
Bolt (M20) for Foundation Bracket 4 pieces
Fork Slot Cover 4 pieces
Bolt (M6) for Fork Slot Cover（M6） 8 pieces
Motorized Isolation Valve（※） 1 piece
Motorized Water Isolation Valve（※※） 1 piece
5.2 Conveying the DSP Air Compressor
■ With a Forklift ■ With a Shop Crane
■ After installing the DSP, plug the fork slots with the fork
slot covers.
Item ※ -marked shall be supplied only for
Item ※※ -marked shall be supplied only for water cooled
Model Total Mass（kg）
DSP-100VAN 2,350
DSP-100VWN 2,200
Model Total Mass（kg）
DSP-90AL(M)N
DSP-100AL(M)N
2,250
DSP-120AMN 2,400
DSP-90WL(M)N
DSP-100WL(M)N
2,100
DSP-120WMN 2,250
39
5. INSTALLING AND PIPING THE DSP

42. 5.3 Installing the DSP Air Compressor
■ Install the DSP in a bright, wide, and airy room as follows:
Ventilating Fan
Maintenance Space Ⓓ
Maintenance Space Ⓒ
Foundation
Maintenance Space Ⓑ
Maintenance Space Ⓐ
If you install the DSP in a
small room, provide a
ventilating fan to keep the
room temperature at 45℃
or lower.
Plug the fork slots with
the fork slot covers
(standard accessory)
Provide a vibration-absorbing
mat if the foundation is vibrative.
If it is too vibrative, look for
another dequate location.
■ Install the DSP in a dry and dust-free room, and avoid the following.
■ Install the DSP on a level floor. ■ Do not install the DSP near a wall. Doing
this may cause the operating sound to
resonate and increase the sound levels.
Raindrops, Basements, Steam Metals, Sand, Other Hard Materials Harmful Gases
These conditions may cause leakage,
condensation, rusting and CPU mal-
function.
Installing on a level floor is required to keep an
adequate amount of lubrication oil in the DSP
and prevent excessive noise and vibration.
Do not set the DSP
on the blocks.
These conditions may cause deterio-
ration of motor insulation level, dam-
age to the air end bearings and CPU
malfunction.
These conditions may cause oil deterio-
ration, corrosion of coolers and peeling
of the rotor coatings.
Prohibited
WARNING
1. Keep flammable solvents or any other hazardous chemicals away from the DSP. Such chemicals may
be sucked by the air end, compressed, and exploded.
2. Do not use fire near the DSP; otherwise the sparks may enter the air end and burn it internally.
CAUTION
● Install the DSP indoors. Installing it outdoors may lead to a damage of the air end due to water vapor,
dust, etc.
● The DSP installation room must have an air intake opening and an air exhaust opening and must be
well ventilated. If the room is poorly ventilated, hot air exhausted by the DSP may cause the room
temperature to rise abnormally and in the worst case lead to damage of the air end.
（ ）
Chlorine, hydrogen sulfide, sulfurous acid, highly
concentrated ozone, and ammonium gases
※ Keep the spaces in the below table
required for cooler-air intake, daily
maintenance and overhauling.
Maintenance Space
Item Air-cooled type Water-cooled type
A Front 1000 1200
B Right 1200 800
C Rear 1000 1000
D Left 1000 1000
40
5. INSTALLING AND PIPING THE DSP [Installing the DSP Air Compressor]

43. 5.4 Piping the DSP Air Compressor
5.4.1 General Instructions
5.4.2 Two-Unit Parallel Piping / Operation
Stop Valve
Condensate Drain Valve
IMPORTANT
Prevent the condensate from flowing back from the main
plant airline pipe.
From the DSP
Main Plant
Airline Pipe
500mm or more
Stop Valve
Motorized isolation valve
(VSD only)
Air Receiver Tank
Stop Valve
Opened
Operating DSP
Non-Operating DSP
Closed
Discharge
Air
Motorized isolation valve
(VSD only)
If you operate only one of the two or more DSPs, keep
fully closed the discharge stop valve of the non-operat-
ing DSP.
If you operate the two DSPs alternately and automati-
cally, use an electric-driven or any other automatic stop
valve, one that can be automatically closed when the
corresponding DSP has stopped.
If you use a solenoid valve as an automatic stop valve,
consult your Hitachi distributor.
A motorized isolation valve is included as a standard
accessory. Arrange for the motorized isolation valve
to be “closed” while the compressor is stopped.
If not using the motorized isolation valve, when
operating one side, provide a stop valve for the dis-
charge piping of the compressor that is not running
and close it completely.
IMPORTANT
Assume that one DSP is operating and another is not. In
case that the discharge stop valve of the non-operating
DSP is opened, a back pressure is applied on that DSP ’s
aftercooler, check valve, etc. As a result the condensate is
produced much more than otherwise; even the Aftercooler
is rusted internally and the check valve is earlier rusted.
① Use the degreased pipe as a plant airline pipe.
② If you connect the DSP directly to a gas pipe, use a
union or flange joint to ease disassembling the DSP
enclosure panels.
③ If a plant airline pipe is longer, use a larger diameter
pipe taking into consideration the pressure loss
through the pipe.
④ If there is a concaved or upright part in a plant airline
pipe, provide a condensate drain valve at its bottom.
41
5. INSTALLING AND PIPING THE DSP [Piping the DSP Air Compressor]
⑤ Install a discharge stop valve on a plant airline pipe
near the DSP.
⑥ If you want to elevate a plant airline pipe near the
DSP, keep a space of 500 mm between the elevated
pipe and the DSP enclosure panel to ease the main-
tenance servicing.
⑦ If you connect the DSP’s discharge pipe to a main
plant airline pipe, run the discharge pipe upwards and
then downwards before joining to the main plant airline
pipe, to prevent the condensate from flowing back.
Discharge Air
Stop Valve
Union or Flange Joint