Van Air Systems HL-2500 - Manual (Page 13)

PAGE 13
USING THE CYCLE SAVER CONTROL SECTION 8
8.1 CYCLE SAVER CONTROL
The CYCLE SAVER control uses a printed circuit board. It is housed
in a NEMA 4X fiberglass enclosure. It has the following features:
- POWER SWITCH
- POWER ON LED
- CYCLE MODE PUSHBUTTON
- FIXED MODE LED
- AUTO MODE LED
The Dryer Status LEDs are located on the front panel of the control
box. Figure 8A shows the location of each. Note: There are six
other LEDs located on the inside of the control box. Reference
SECTION 8.5.
Start the dryer per SECTION 5.1. When the left tower is pressurized
and on line drying the process air, the corresponding LEFT TOWER
DRYING LED will be lit. When the right tower is pressurized and on
line drying process air, the corresponding RIGHT TOWER LED is
illuminated. The operation timing sequence of the dryer is shown in
Figure 8B TIMING CHART FOR CYCLE SAVER.
8.2 SETTING THE CYCLE MODE
Pressing the Cycle Mode Pushbutton will alternate between the FIXED
and AUTO modes. This will light either the Fixed or Auto Mode LED.
8.2-1 OPERATING THE DRYER IN THE FIXED MODE
When operating the dryer in the FIXED MODE, press the Cycle
Mode Pushbutton until the Fixed Mode LED is lit. The dryer will not
utilize the ENERGY SAVINGS feature.
The fixed cycle is a normal 10 minute cycle. The dryer changes
towers every five minutes. The dryer goes through a normal tower
changeover sequence (repressurization, tower changeover,
depressurization).
FIGURE 8A CYCLE SAVER CONTROL BOX
The SWITCHING FAILURE ALARM is operational in both the
FIXED and AUTO modes.
8.2-2 OPERATING THE DRYER IN AUTO MODE
When operating the dryer in the AUTO MODE, press the Cycle
Mode Pushbutton until the Cycle Mode LED is lit.
The dryer will operate in the start up cycle for the first 20 minutes of
operation at every start up. After the start up cycle has been
completed, the dryer will operate in the mode that the Cycle Mode is
set (FIXED or AUTO).
In the Auto Mode, the length of time that a tower is in the drying
stage is controlled by the humistat set point adjustment on the
printed circuit board.
8.2-2A ENERGY SAVINGS
At the end of a normal regeneration stage, if the tower humistat
indicates a good dew point, ENERGY SAVINGS has been
activated. If the dew point is not low enough to activate ENERGY
SAVINGS, the dryer will switch towers.
When ENERGY SAVINGS is activated, the ENERGY SAVINGS
LED is illuminated. The purge exhaust valve on the regenerating
tower is closed and that tower comes up to full line pressure. No
purge air will be exhausted at this time.
The tower that was in the drying stage will remain on line and
drying the process air until the dew point rises to the set point of
the humistat.
The maximum time a tower can stay in energy savings is four
hours. This is to prevent channeling of the desiccant under very
low flow conditions.
- ENERGY SAVINGS LED
- SWITCHING FAILURE LED
- RESET PUSHBUTTON
- L/R TOWER DRYING LEDS
- L/R TOWER REGENERATING LEDS