Doosan NHP10-425WCU-EU-FX-T3, Operation And Maintenance Manual

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Operating & Maintenance Manual Operating Instructions
32
Normal Operation
The Operator may observe and monitor operating parameters using the STATUS and
SCROLL buttons. In the event the machine controller detects a parameter outside normal
operating limits, first an ALERT message will appear on the Message Display.
In the event the machine controller detects a parameter at a dangerously high or low level, the
machine will be automatically unloaded and stopped with the cause of the SHUTDOWN
shown on the Message Display and warning lights will flash.
Delivered air volume at set point pressure is accomplished by two methods:
1. Compressor inlet butterfly valve and blowdown valve are controlled by a
solenoid which directs oil to a cylinder by the INTELLISYS Controller logic
(valves syncronized together).
The compressor is either loaded (inlet valve fully open/blowdown valve fully
closed) or unloaded (inlet valve fully closed/blowdown valve fully open).
2. Engine speed varies between 1200 RPM and 1800 RPM while compressor is
loaded to match the required volume flow.
Full flow at set point pressure at 1200 RPM is approximately 1000 CFM.
Full flow at set point pressure at 1800 RPM is 1500 CFM.
Operation-Loaded
Assume engine has been started and is running in the unload state at 1200 RPM. If there is
air demand (pressure falls below the load point pressure), compressor will load at 1200 RPM
by oil pressure to the cylinder (opens the butterfly valve and closes the blowdown valve). This
provides 1000 CFM of air. As air demand rises and falls, engine speed is controlled between
1200 RPM and 1800 RPM to match the required flow while maintaining rated pressure. Full
flow is 1500 CFM at 1800 RPM.
CAUTION
!
Keep side door closed or engine overheating will occur.
Operation-Unloaded
If air demand falls below 1000 CFM at 1200 RPM (Pressure rises above the unload point
pressure), the compressor will unload by relieving the oil pressure in the cylinder, thereby
closing the inlet valve and opening the blowdown valve. The unit then runs at 1200 RPM
unloaded with no air delivery. If air demand increases (pressure falls to below the load point
pressure), the compressor reloads as stated in (1) above to meet the required air demand.
See following page for INTELLISYS CONTROLLER LOGIC Diagram.