Q3 & Qht Controls for Direct Expansion Systems Modes of Operation
L-2516 ENGLISH 7
The modes available are: Off, Cool, Heat, Auto (automatically switches between Cool and Heat Modes, depending on set point
requirement), Aux Heat (optional) and Dehumidification Mode.
DEHUMIDIFICATION MODE
Press the MODE button until the DEHUMIDIFY LED indicator lights (Q3) or the word DEHUMIDIFY appears in the display
(Qht). The display flashes “HU” during this mode of operation. When Dehumidification Mode is activated, the Humidity Control
Program automatically turns the air conditioning system on at timed intervals to remove moisture from the air. The system is
programmed at the factory for average values. To change the factory settings, see Programmable Function “10:
Dehumidification Pre-Circulation Time” on page 10, Programmable Function “11: Dehumidification Time” on page 10, and
Programmable Function “12: Dehumidification Overall Time Period” on page 10.
ADJUSTING THE SET POINT
To view the set point, momentarily press and release the UP or DOWN button. To adjust the set point, press the UP or DOWN
buttons to set the desired room temperature (press and hold either button to scroll). The set point range is 55-99°F (12.8-
37.2°C). After selecting the desired set point temperature, if no buttons are pressed for three seconds the display automatically
reverts to showing the inside cabin temperature. Inside cabin temperature is continuously displayed.
• Q3 - The upper center dot in the display lights when set point is being adjusted.
• Qht - The word SET appears in the display while set point is being adjusted.
FAN OPERATION AND CONTROL
Press the FAN button to adjust the fan speed while in Manual Fan Speed Mode or to switch between Manual and Automatic Fan
Speed Modes. The fan may be run manually whether the system is on or off. Automatic Fan Speed Mode can only operate
when the system is on. Fan behavior also depends on how the Fan Mode function is programmed: “C” for continuous or “I” for
intermittent running with the compressor. See Programmable Function “7: Fan Mode” on page 9.
• Q3 - When in Manual Fan mode, the AUTO Fan LED is off.
• Qht - The word MANUAL appears in the display when in Manual Fan mode.
MEMORY
The control has nonvolatile memory requiring no batteries or backup power. When power is lost, the operating parameters are
retained indefinitely. When power is restored, the control resumes operating as last programmed.
DISPLAY INSIDE CABIN TEMPERATURE
The control continuously displays inside cabin temperature. If Mode or Set Point is changed, after three seconds the display
automatically reverts to showing inside temperature. If inside temperature is greater than 99°F (37°C) or less then 0°F (-17°C),
the display shows either 99°F (37°C) or 0°F (-17°C) respectively as the maximum or minimum inside temperature.
DIMMING THE DISPLAY
Press the MODE and UP buttons simultaneously and repeatedly to select the brightness setting for the display.
SLEEP MODE
Sleep Mode dims all LEDs (Q3) or turns off the backlight (Qht). When in Sleep Mode, press any button to brighten the display,
and then operate as usual. See Programmable Function “18: Sleep Mode” on page 11.
LOCKOUT DISPLAY MODE
Press the MODE and UP and FAN buttons simultaneously to select the Lockout Display Mode setting. This mode locks the
display in the current mode selected. If a button is pressed, the display flashes “LC” for 2 seconds then goes back to displaying
the inside temperature. In Lockout Mode, the display shows inside temperature and the indicators operate as normal, but all
button presses are ignored until MODE and UP and FAN buttons are pressed simultaneously, then “UL” displays momentarily
and the buttons are unlocked for normal operation. In Lockout Mode all sensors operate as normal and any fault and error
codes will be displayed.
NOTE
When the system is in Dehumidification Mode, all system safeguard controls remain active. For example, if the line
voltage falls below preset limits, the system will automatically shut down. Or, if AC power is interrupted, the system
will automatically resume operation in Dehumidification Mode when power is restored.
To Next Page
Loading...
Need help?
General
