SEQUENCE OF OPERATION
PAGE 23
ENGLISH
Auto Mode
With the system turned on, press the AUTO button on the
remote control. The system will change to the auto mode of
operation.
As the room is cooled or heated, the system will automati
-
cally switch between cool mode, fan mode, and heat mode.
There is a minimum 15 minute operating time between mode
changes.
Dry Mode
Overview
The temperature control range is 60°F - 86°F. This mode is
used for dehumidification.
(Tr= room temperature Ts= set temperature)
When Tr> Ts+ 4°F, the compressor will turn on and the indoor
fan will operate at the set speed.
When Ts ≥ Tr ≥ Ts+ 4°F, the compressor will operate at the high
dry frequency for 10 minutes, then at the low dry mode for 6
minutes. The indoor fan will operate at low speed.
When Tr< Ts, the outdoor unit will stop, and the indoor fan will
stop for 3 minutes, then operate at the low speed option.
Automatic fan speed:
When Tr>= Ts+ 9°F, High speed
When Ts+ 5.4°F ≥ Tr< Ts+ 9°F, Medium speed
When Ts+ 3.6°F ≥ Tr< Ts+ 5.4°F, Low speed
When Tr< Ts+ 3.6°F, Light speed
Note: TURBO and QUIET mode must be set using the remote
controller.
If the outdoor fan is stopped, the indoor fan will pause for 3
minutes. If the outdoor fan is stopped for more than 3 min
-
utes, and the compressor is still operating, the system will
change to light speed mode.
Indoor Unit
To enter the dry mode, point the infrared remote control at
the indoor unit and press the power button, then press the
DRY mode button if not already set to dry mode.
The signals received by the infrared receiver are relayed to the
main board of the indoor unit to turn the system on and set it
to dry mode.
The indoor unit main board will illuminate the display, indicat
-
ing the set temperature and current status of the unit.
The PCB will then signal the louver stepper motor to open the
louver to either a stationary position, or one of several oscil
-
lating modes.
As the louver opens, the indoor fan motor will operate at the
speed last set. The fan motor has a feedback circuit which
provides the main board with information for controlling the
speed of the fan motor.
Indoor Temperature Sensors
The indoor unit has two sensors that provide temperature
information to the PCB. An ambient temperature sensor and
pipe temperature sensor are used for controlling the system
during dry mode. The resistance values of the sensors will
vary with temperature. The resistance to temperature values
can be found using a temperature /resistance chart specific to
the sensor being checked.
Communication
The indoor and outdoor unit main boards communicate via a
digital signal on the wire connected to terminal 3 of each unit.
A splice or break in this wire will cause a communication error.
When a command is received from the remote control, the
indoor unit main board communicates with the outdoor unit
main board via the terminal 3 wire to perform the requested
function.
Outdoor Unit
Upon a request for dry mode, the outdoor unit main board
applies power to the fan motor and compressor. Depending
on system cycling, there may be up to a 3 minute wait period
before the compressor and outdoor fan start.
WARNING: Do not measure compressor voltages, damage to
the meter may result.
The outdoor unit PCB also controls the position of the EEV
(Electronic Expansion Valve) to regulate the flow of refrigerant
to the indoor unit evaporator coil.
Outdoor Temperature Sensors
Five temperature sensors located in the outdoor unit provide
information to the outdoor unit PCB for control of the system
during dry mode.
The outdoor ambient temperature sensor provides the tem-
perature of the air drawn into the condenser coil.
The defrost temperature sensor A provides the temperature
sensed at the output of the condenser coil.
The defrost temperature sensor B provides the temperature
sensed at the middle of the condenser coil.
The suction line temperature sensor provides the tempera-
ture sensed at the incoming suction line pipe.
The compressor discharge sensor provides the temperature
sensed at the discharge pipe of the compressor.
To stop dry mode, press the power button to turn the system
off, or change to another mode.
