SEQUENCE OF OPERATION
PAGE 22
ENGLISH
System Power
The 240 Volt AC power for the system connects to terminals
1(N), 2(L), and ground of the outdoor unit terminal block. This
terminal block also has terminals to connect power to the
indoor unit.
The voltage readings between terminals 1(N) and ground, and
terminals 2(L) and ground should be 120 VAC. The voltage
reading between terminals 1(N) and 2(L) should be 240 VAC.
One additional connection on the terminal block (3) is for the
communication wire between the indoor and outdoor units.
NOTE: Mis-wiring of these connections may cause improper
operation or damage to system components.
Cool Mode
Overview
The temperature control range in cooling mode is 60°F - 86°F.
The temperature set by the remote control and the indoor
unit ambient temperature sensor will determine if a call for
cooling is needed. If a call for cooling is justied, the call is
communicated from the indoor unit to the outdoor unit. The
indoor unit louver will open using a stepper motor, and the
indoor fan will operate at the speed last set. The outdoor unit
will determine the position of the EEV and speed (frequency)
of the compressor. There can be a delay of up to 3 minutes
before the outdoor unit fan and compressor start.
The speed of the indoor fan can be controlled manually by
the user or automatically by the system. The speed can be
changed between LOW, MEDIUM, and HIGH. The predeter
-
mined conditions for automatic control are as follows:
(Tr= room temperature Ts= set temperature)
High Speed: Tr ≤ Ts + 5.4°F
Medium Speed: Ts + 1.8°F ≤ Tr < Ts + 5.4°F
Low Speed: Tr ≤ Ts + 1.8°F or when the sensor is o.
There will be a 2 second delay when manually controlling the
speed.
The outdoor unit temperature sensors: outdoor ambient,
defrost, suction line, and compressor discharge, used in
conjunction with the indoor temperature sensors, indoor
ambient and coil, provide information to the outdoor control
board to monitor the system and regulate the frequency of
the compressor, EEV positioning, and outdoor fan speed to
achieve the desired room temperature.
When cooling has been satised, the outdoor unit compres-
sor will turn o, followed by the outdoor fan. The indoor unit
fan will continue to run.
If the system detects a malfunction, it may shut down or
show an error code on the indoor unit display board and/or
outdoor unit main board LED.
Indoor Unit
To enter the cool mode, point the infrared remote control
at the indoor unit and press the power button, then press
the COOL mode button if not already set to cool 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 cool mode.
The indoor unit main board will activate the display of the
indoor unit, illuminating the display, indicating the room tem
-
perature and current status of the unit.
The indoor unit main board will signal the louver stepper mo-
tor to open the louver to either a stationary position, or one
of several oscillating modes.
As the louver opens, the indoor unit main board will power up
the indoor fan motor, operating the fan at the speed last set.
The indoor fan motor has a feedback circuit which provides
the indoor unit main board with information for controlling
the speed of the fan motor.
Temperature Sensors
The indoor unit has two sensors that provide temperature
information to the indoor unit main board. The sensors: an
indoor ambient temperature sensor, and coil temperature
sensor, are used for controlling the system during cool mode.
The resistance values of the sensors will vary with tempera-
ture. The resistance to temperature values can be found
using a temperature / resistance chart specic 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 cooling, the outdoor unit main board
applies power to the outdoor 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 volt meter may result.
If the ambient room temperature is less than the set tem-
perature, yet higher than 2°F below the set temperature, the
system will adjust the running frequency of the compressor
automatically according to changes in ambient temperature.
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