Gardner Denver PUREAIR EWC99C, Руководство по эксплуатации и обслуживанию

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13-11-607 Page 16
When first starting, the controller will keep the compressor fully unloaded and blown down until the
system pressure drops below the load pressure.
Low Demand Mode Operation - This mode is similar to the “Continuous Run” mode, except for its behavior
under unloaded conditions. If the blowdown timer has completed its cycle when the next unload operation
takes place, the controller will not reload the package until the line pressure has reached the “load” level.
Otherwise, if the blowdown timer is still active, the machine will reload the package when the line pressure falls
halfway between the “unload” and “load” levels.
Automatic Mode Operation - This mode provides automatic start and timed stop, and is best used in
applications with long unloaded periods and adequate storage to allow the compressor to be stopped for
periods of light demands. Operation during periods of moderate to heavy demands is identical to the low
demand and constant run modes described above.
The automatic time delay is adjustable from 5 to 20 minutes. If the controller operates unloaded for this
period with no demand, the compressor drive motor is halted to eliminate its power consumption. The
controls will remain in this state until pressure drops below the load pressure.
This is the most common selected mode of operation, as it automatically will operate the compressor unit
in the most efficient manner for the demand of the air system.
When packages are sequenced and rotated, it is not recommended to engage the pneumatic pilot valves
for flow modulation. See “Subtractive Valve”, page 30, under “Other Control Devices” for details.
Sequence Mode Operation - This mode provides for communication between controllers, operating
only as many as are required for economical operation. This is best used on applications with large
storage capacity and diverse loads. The lead unit will operate identically to the automatic mode;
operation will be automatically staged for each lag unit (up to 8 total). For more information, refer to the
sequencing instructions later in this chapter.
An optional expansion board must be installed for sequencing operation. Communication between
controllers is achieved by interconnection of a communications cable to expansion board connectors. A
”unit number” must be assigned to each unit in this mode, but the display will indicate the unit’s actual
operating ranking.
AUTO-SENTRY W CONTROL DISPLAY
The display above the keypad is used to provide operating information to the user. If a shutdown has
occurred, the display will indicate the cause.
During normal operation, the display will show the system pressure, compressor discharge temperature,
total running hours, and operation mode. Alternate displays are available by pressing the [?] INFO or the
keypad cursor [<] [>] keys, and will be identified on the display. These include:
Water Filter Differential Pressure DIF PRES
Reservoir Pressure RES PRES
Water Injection Pressure INJ PRES
System Pressure SYS PRES
Compressor Discharge Temperature DIS TMP
Total Hours TOT HRS
Loaded Hours LOAD HRS
Remaining Blowdown Time BD TMR
Remaining Auto Time AUTO TMR