14
MHGRV-X Field Technical Guide
LCD SCREENS
Status and Alarm Screens
Status Screens
Refer to the following map when navigating through the Status
Screens. From the STATUS Screen, press
<ENTER>
to scroll
through the screens.
STATUS
Status Screens shown below will scroll automatically if LCD
display is left on this screen for 20 seconds.
MODE
REHEAT
MODE
This screen displays the current mode of operation of the
MHGRV-X. The mode options are:
OFF:
This mode will display if the unit is not in Dehumidification
Mode and there is no call for Modulating Hot Gas Reheat (MHGR).
REHEAT:
During Dehumidification, the unit will enter the Reheat
Mode and will begin to modulate the MHGR Valve to maintain the
Supply Air Temperature Setpoint. The unit will leave the Reheat Mode
when the unit leaves the Dehumidification Mode.
FLUSH:
This mode will display if the unit is performing a cooling
flush cycle or a reheat flush cycle (see Additional Features,
page 11
).
AUX:
If Aux operation has been enabled, a 0-10 VDC signal can be
used to proportionally modulate the MHGR Valve between 0 – 100 %.
FORCE!:
The unit is in the Force Mode.
VLV POS
100%
VALVE POSITION
0 to 100 percent
SA TEMP
XX.X
SUPPLY AIR TEMPERATURE
40ºF to 150ºF or 5ºC to 65ºC.
If no sensor is detected, screen will display “NO SENSR”
Alarm Screens
Refer to the following map when viewing Alarm Screens. These
screens will display automatically when alarms are present. For
more information, see
pages 16 and 17
.
ACTIV SP
XX.X
ACTIVE SUPPLY AIR SETPOINT
Calculated from SAT setpoint and reset signal. Displays
INACTIVE when in OFF Mode or not needing to be calculated.
FLUSHTMR
COOLING
FLUSHTMR
XX MIN
FLUSH
CYCLE ON
FLUSH TIMER AND FLUSH STATUS
Flush Timer screen will display if the unit is in Cooling Flush Mode,
Reheat Flush Mode, or Disabled. It will then display the time remain-
ing in minutes until the Flush Cycle begins. If the unit is in the Flush
Cycle, it will display FLUSH CYCLE ON.
ALARMS
The alarms are as follows:
NO ALARMS:
This will be shown if there are no current alarms.
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.
