23
MODGAS-X Technical Guide
STATUS
Status Screens shown below will scroll automatically if LCD display
is left on this screen for 20 seconds.
MODE
HEAT
MODE
This screen displays the current operating mode of the MODGAS-X.
The mode options are:
OFF:
This mode will display when there is no call for heat and heating
has been disabled.
HIGH FIRE:
Each time Heat is activated, the unit will first go into High
Fire Mode. During this mode, the unit will remain at maximum fire. The
unit will leave this mode once proof of fire has been established.
HEAT:
After High Fire, the unit will enter the Heat Mode and will begin
to modulate the gas valve to maintain the Heating Supply Air Setpoint
(SAT). The unit must remain in this mode for a minimum run time of
one minute. While in Heat Mode, the screen will display the staging
status—HEAT STAGE 1 to STAGE 15. If Modulating Staged Heat, the
screen will display MOD HEAT. Once the call for heat goes away, the
unit will leave the Heat Mode.
CUTOFF:
The Cutoff Mode occurs if the SAT rises above 200˚F.
During Cutoff Mode, the Heat will be disabled for a fixed delay period.
If the SAT falls below 200˚F and the delay period has expired, the unit
will re-enter the Heat Mode.
FORCE:
Force Mode.
SAT FAIL:
The Supply Air Temperature Sensor has been disconnected
for more than 60 seconds. This alarm will be disabled when the sensor
is reconnected.
VLV POS
100%
VALVE POSITION
0 to 100%
SA TEMP
XX.X
SUPPLY AIR TEMPERATURE
40ºF to 200ºF (5ºC to 93ºC)
If no sensor is detected, screen will display “NO SENSR”.
ACTIV SP
XX.X
ACTIVE SUPPLY AIR SETPOINT
Calculated from SAT Setpoint and Reset Signal in Stand-Alone
Mode. In Communications Mode, the AAON unit controller sends the
setpoint.
FAN SPD
OFF
FAN SPEED
OFF, HIGH, LOW
Status Screens
Refer to the following map when navigating through the Status
Screens. From the STATUS Screen, press
<ENTER>
to scroll
through the screens.
Alarm Screens
Refer to the following map when viewing Alarm Screens. These
screens will display automatically when alarms are present. For
alarm troubleshooting, see
page 30
.
ALARMS
ALARMS
The alarms are as follows:
NO ALARMS:
This will be shown if there are no current alarms.
SAT CUTOFF:
This indicates a Supply Air Temperature Cutoff Alarm
condition which is activated if the SAT has risen above 200ºF. The
alarm will go away if after a fixed delay period the SAT has dropped
below 200ºF.
SAT FAIL ERROR:
The Supply Air Temperature sensor has been
disconnected for more than 60 seconds. This alarm will be disabled
when the sensor is reconnected.
COMM T/O ERROR:
Communications have been lost with the
AAON unit controller. This alarm will disable when communications
resume.
LCD SCREENS
Status and Alarms Screens
