Dometic Qht User Manual

Operator Controls and Display Panel Q3 and Qht Controls for Direct Expansion Systems
6 L-2516 ENGLISH
OUTSIDE AIR TEMPERATURE SENSOR - OPTIONAL
Install the optional outside air temperature sensor to monitor temperature outside the cabin. Outside air sensor cables are
available in various lengths. Mount the sensor outside but not in direct sunlight. Plug in the sensor’s 6-pin connector to the
socket labeled “Outside Temp” (white) located on the edge of the circuit board.
HUMIDITY SENSOR - OPTIONAL
Install the optional humidity/temperature combo sensor to monitor the relative humidity of the cabin. Locate the sensor in the
same location as the ambient air temperature sensor. Plug in the combo sensor’s 6-pin connector to the “Inside Temp” socket
located on the edge of the circuit board. The control board automatically detects the presence of this combo sensor and
immediately starts measuring humidity.
OPERATION
OPERATOR CONTROLS AND DISPLAY PANEL
For the button locations and display functions, refer to Figure 1, Table 1 on page 3 for the Q3 control and to Figure 2, Table 2 on
page 4 for the Qht control.
BUTTON FUNCTIONS
• POWER button (Qht only) - Press and release to toggle between the On and Off Modes.
• MODE button - Press and release to toggle between the Off (Q3 only) and all other modes of operation.
• UP button - Press and release to display the set point. Press and hold the UP button to increase the set point. Set
point increases one degree each time the button is pressed.
• DOWN button - Press and release to display the set point. Press and hold the DOWN button to decrease the set
point. Set point decreases one degree each time the button is pressed.
• FAN button - Press to select the Automatic Fan Mode, the Manual Fan Mode, or to advance through the manual fan
speeds.
• Display Seawater Temperature (optional) - Press the FAN and UP buttons simultaneously to display the seawater
temperature (optional). If the seawater temperature is not available, open or shorted (closed), the display flashes “- -”
instead of a temperature reading.
• Q3 - The display flashes “SE” for one second then the seawater temperature displays in two segments: The
display flashes the first digit of the seawater temperature for one second, then the next two digits of the seawater
temperature for one second. The cycle repeats until the buttons are released.
• Qht - The word WATER displays, “SE” flashes for one second, then the seawater temperature displays in two
segments: The display flashes the first digit of the seawater temperature for one second, then the next two digits
of the seawater temperature for one second. The cycle repeats until the buttons are released.
• Display Outside Temperature (optional) - Press the FAN and DOWN buttons simultaneously to display the outside
temperature (optional). If outside temperature is not available, open or shorted (closed), the display flashes “- -”
instead of a temperature reading.
• Q3 - The display flashes “OU” for one second then the outside temperature displays in two segments: The display
flashes the first digit of outside temperature for one second, then the next two digits of outside temperature for one
second. The cycle repeats until the buttons are released.
• Qht - The word OUTSIDE displays, “OU” flashes for one second, then the outside temperature displays in two
segments: The display flashes the first digit of outside temperature for one second, then the next two digits of
outside temperature for one second. The cycle repeats until the buttons are released.
• Display Relative Humidity (optional) - Press the MODE and UP and DOWN buttons simultaneously to display the
relative humidity (optional). “HS” displays for one second then the two digits of relative humidity display for one second.
The cycle repeats until the buttons are released. If HS is not available, open or shorted (closed), the display flashes
“- -” instead of the humidity reading.
MODES OF OPERATION
POWER ON AND BASIC MODES
Press the MODE (Q3) or POWER (Qht) button to turn the system on. In three seconds, the system will start operating in
whichever mode it was running prior to the last shut down. For the initial startup, the control will be in Cool Mode.To change
mode before the system starts, press the MODE button before the three-second startup completes (while the display is
flashing). Or, while the system is on, press the MODE button at any time to change the mode.

Dometic Qht Specifications

General

Brand	Dometic
Model	Qht
Category	Control Unit
Language	English