XtremeMac XGC-1 - Manual (Page 7)

FUZZY LOGIC  CO
2
CONTROL (Continued)
HOW TO PERFORM “AUTO-TUNING”
The Auto-Tuning function takes from 1 ½ to 2 ½ hours to complete. DON’T WORRY. It is completely automatic once the test
is started. However, before performing an Auto-Tuning, you MUST prepare the area for the procedure. This may take at the
most 15 minutes.
1) During the Auto-Tuning, the area must be operating normally. Circulating fans must remain operating.
2) Exhaust and/or cooling fans which bring fresh air into the area must be disabled. If heat or humidity build-up is a problem
during the 2-hours required, reduce the lighting or other heat loads temporarily until the test is completed.
3) Set the CO
2
flow-gage to the setting most likely to be correct for your area. If no estimate is known, set it near the middle
of the range and increase it if the first Auto-Tuning does not provide consistent control.
4) Turn the thermostat & humistat responsible for running the exhaust fans all the way to the maximum setting until the
Auto-tune is complete.
5) Close the CO
2
tank valve. Connect the CO
2
valve or generator to the XGC-1. There should be no CO
2
flowing out of the
tank until the test is started.
6) Set the SV (desired CO
2
level) to the desired level. (See Changing Set-Point)
7) Press [SEL] for 1 second. (RUN will be displayed)
8) Press the [Down] button one time. (AT will be displayed)
9) Press the [SEL] button once. (0 is displayed)
10) Press the [UP or DOWN] button to bring up 1. (1 is displayed)
11) Press the [SEL] button once. The decimal point will begin to flash until the Auto-Tuning procedure is completed. The CO2
outlet will be energized.
12) Quickly open the CO
2
tank valve and verify CO
2
is flowing out of the flow-gage / regulator.
13) Get out of the area and do not disturb the area for a minimum of 2 hours. After two hours, enter the area and confirm the
decimal point has stopped flashing, which indicates the test is complete.
14) Reconnect the Exhaust fans, CO
2
Disable cable and return the area to normal operation while monitoring the level of CO
2
.
Do not continue to stand next to the XGC-1 while monitoring. Just keep an eye on the display and record the level every
30 minutes or so. Also try to observe the unit reacting to and recovering from the Exhaust fans operating. The level should
drop down to 800 or less and then recover quickly without overshooting the setpoint more than 150 PPM.
15) If after operating a day or two you are not getting good consistent control, (+/- 100 PPM from set point) it may be a good
idea to perform a second Auto-Tuning.
*NOTE: If your CO
2
tank runs out for a period of time, the control may take a few hours to re-stabilize, this is normal.
CHANGING THE SETPOINT (SV)
The XGC-1 has an adjustable set point. The set point is the minimum CO
2
level in Parts-Per-Million you want to maintain. The
face of the Fuzzy Logic controller has 5 led indicators on the front. The one marked (SV) is illuminated when viewing and / or
changing the set point.
1) Press (SEL) momentarily. The SV indicator will light up and the current set point is displayed.
(The XGC-1 is factory set @ 1500 PPM)
2) Use the (UP / DOWN) buttons to change the set point to your desired level. Normally between 1250 –2000 PPM.
3) Press the (SEL) button momentarily to accept the change.
CHANGING CONTROL MODES
People operating compressed CO
2
systems will definitely benefit from the XGC-1’s “Fuzzy Logic”. But some people who are
using LP / Natural gas generators may want to extend the life of their generator by changing the XGC-1’s control mode to ON /
OFF. When operating in ON / OFF mode, the rapid pulsing of the control solenoid is eliminated. The XGC-1 will still control
the CO
2
generator with extreme accuracy. A preset hysteresis (dead-band) of 50PPM still allows the XGC-1 to control the CO
2
to an average level of +/- 200 PPM. For comparison’s sake, the average accuracy of the Fuzzy Logic control mode is around
+/-25PPM. Follow the procedures listed below to easily change the control modes on the XGC-1.
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