Troubleshooting The Air Compressor - Hitachi NEXT Series Instruction Manual

4.2 Troubleshooting the Air Compressor

Most likely problems, causes, and remedies are described below.
Causes LCD Indication
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 ：
P r e s s
＜ 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
Shutdown –
1st-stage dis- ＜ A L A R M ＞
charge air tem-
D I S . T E M P . 1 ：
perature and/ or
pressure too high
P r e s s
＜ S H U T D O W N ＞
H I G H D I S . T E M P ：
P r e s s
Shutdown –
2nd-stage dis-
＜ A L A R M ＞
charge air tem-
D I S . T E M P . 2 ：
perature too high
P r e s s
Shutdown –
2nd-stage suction ＜ S H U T D O W N ＞
air temperature
2 N D S U C T . T E M P ：
too high
P r e s s
Shutdown –
Oil temperature ＜ S H U T D O W N ＞
too high
O I L ：
P r e s s
Shutdown –
Oil pressure too
＜ S H U T D O W N ＞
low
O I L ：
P r e s s
Shutdown –
Main motor and/ ＜ S H U T D O W N ＞
or ancillary motor
O V E R L O A D ：
overloading
P r e s s
＜ S H U T D O W N ＞
O V E R L O A D ：
P r e s s
Shutdown –
＜ F A I L U R E ＞
Inverter tripping/
restarting
S Y S T E M R E T R Y ：
4. TROUBLESHOOTING [Troubleshooting the Air Compressor]
1. Power supply switch - Off
2. Power - Failed
3. Power cord - In a reversal phase
R E V
connection
R E S
4. Power cord - In a phase-lacking
a f t e r C H K .
connection
R E S
a f t e r C H K .
1. 2nd-stage AIR END air intake effi -
ciency - Lowered
2. Air intake fi lter - Dirty
3. Temperature of Suction Air-High
R E S
a f t e r C H K .
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
R E S
a f t e r C H K .
1. Cooling water pump – Failed, or
Cooling water pressure – Fluctuating
2. Intercooler – Dirty
R E S
a f t e r C H K .
1. Oil cooler – Dirty
2. Room temperature – High
3. Oil temperature control valve –
H I G H T E M P
Failed
R E S
a f t e r C H K .
1. Oil strainer and/or oil fi lter – Dirty
2. Oil level – Low
L O W T E M P
R E S
a f t e r C H K .
1. Power supply voltage – Low
2. Discharge air pressure – Too high
M A I N
R E S
a f t e r C H K .
1. Power supply voltage – Low
2. Cooling fan motor – Failed
S U B
R E S
a f t e r C H K .
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.
Causes
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
1. Contact your Hitachi distributor.
2. Clean the air intake fi lter.
3. Lower the suction air temperature.
1. Replace the check valve.
2. Clean the Suction throttle valve.
Note: For information about the Suction
1. Check the cooling water system.
2. Clean the intercooler
1. Check the oil cooler.
2. Reduce the room temperature.
3. Check the oil temperature control
valve.
1. Clean the oil strainer
2. Replace the oil fi lter.
3. Add the oil.
1. Rectify the power supply voltage.
2. Check the suction throttle valve
3. Check the capacity control system.
1. Rectify the power supply voltage.
2. Check the cooling fan motor.
(Measure insulation resistance etc.)
1. Rectify the power supply voltage.
2. Check the capacity control system.
3. Measure insulation resistance etc. or
check the main motor.
Corrective Remedies
when connecting the power.
bypass valve, see page 29.
35