MMD Equipment 185S-6C1 - Manual (Page 36)

4. Operation
4-18
[ FUNCTION OF AUTO IDLE CONTROL ]
First engine speed drops to the minimum speed by
pressure regulator , owing to reduction of air con-
sumption. Later the air consumption is reduced fur-
ther, the unloader valve gradually closes and intake
negative pressure increases. In this stage, the pres-
sure sensor detects the intake negative pressure.
Then when the intake negative pressure becomes
higher than the set pressure, the AUTO IDLE lamp
flickers at short intervals.
When this condition continues for a certain time, the
solenoid valve for purge
mode functions to start purge mode operation. Con-
sequently, the pressure inside separator receiver
tank drops and reduces the power of compressor air
end. In this stage, the lamp “AUTO IDLE” flickers at
longer intervals.
Next, when the pressure for load down to the purge
releasing pressure owing to the increase of air
consumption, the solenoid valve for purge mode
operation gets “OFF ” and it is transferred to nor-
mal operation. In this stage, the lamp “AUTO IDLE”
goes on.
[Standard set values prior to delivery ex-works ]
Item
Set prior to delivery
ex-works
Setting range
Purge releasing pressure VR3 80 psi(5.5bar) 50-95 psi(3.5 – 6.6bar)
Purge starting intake negative pressure VR2 30％ 0 - 80%
Timer set to be expected for purge
modeVR1
10 seconds 10 - 112 seconds
Function Conditions of AUTO IDLE lamp
Lamp flickers at short in-
tervals.
Lamp flickers at longer in-
tervals.
Lamp goes on.