Start-Up For Unit Mounted; Fan Operation - A & T International 1 Service Manual

START-UP FOR UNIT MOUNTED INFRARED COMPATIBLE CONTROL (ONLY)
1. LCD Display
2. Temp. Set Point Down Button
3. Temp. Set Point Up Button
On/Off Switch
On/Off switch is used to turn equipment on or off. In off
mode display will be blank and all LED indicator lights will
be dark. To turn unit on press On/off button once. Room
temperature will be displayed and amber LED indicators will
show fan speed and mode selections (Figure 5).
Mode Switch (System Switch)
Mode button allows for selection of desired mode of
operation. Colored LED indicators light next to selected
mode. With each successive press of Mode button,
selection rotates between Heat, Cool, Fan or Dry
mode. If dipswitches are set for cooling only (off –
off) Heat and Dry are not accessible (Figure 5).

Fan Operation

Indoor unit utilizes two-speed motor with three operational
fan modes. Fan button allows selection of desired fan
setting. Amber LED indicator lights next to fan speed
selection. If Auto fan mode is selected then LED indicator
also lights next to Auto.
High and Low are constant fan settings. Fan will operate
continuous regardless of set point or room temperatures.
Auto mode is cycling fan setting.
UNIT MOUNTED INFRARED COMPATIBLE CONTROL
1
3
2
4. Infrared Sensor
5. Power ON/OFF Button
6. Mode Indicator LEDs (HEAT, COOL, FAN, DRY)
Figure 5
5 6
4
Auto fan mode can only be selected if unit is in Heat or
Cool mode. In Auto mode fan cycles with call for Heat
or Cool. Fan speed is determined by microprocessor
and speed adjustment is made according to room and
setpoint temperatures. Fan will switch to High speed when
room temperature deviates by more than two degrees
from setpoint. Fan will switch to low speed if deviation is
one degree. When room temperature reaches setpoint
temperature heat/cool call will then be dropped. Fan will
stay on for additional 60 sec. to purge unit of any residual
energy. After fan has been off for ten minutes, fan will
cycle on for 60 seconds. This is done so microprocessor can
sample room air and also help eliminate room temperature
stratification.
When unit is in Dry mode fan speed remains constant at
low speed. While unit is in Fan mode, Auto is bypassed
and only High or Low are available (Figure 5).
Cooling Only Operation
For cooling operation, turn unit on via On/off button.
Select Cool mode via Mode button. Room temperature
is displayed. By pressing either Up or Down arrow once,
setpoint temperature appears. Setpoint temperature can be
changed with each successive press of Up or Down arrow
buttons or by holding button in. Place setpoint temperature
below room temperature.
14
7 8 9
7. Mode Selection Button
8. Fan Operation Button
9. Fan Indicator LEDs (HIGH, LOW, AUTO)