SEQUENCE OF OPERATION
PAGE 20
ENGLISH
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 justified, 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 predetermined 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 off.
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 con
-
junction 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, the EEV, and outdoor fan speed, to achieve the
desired room temperature.
When the call for cooling has been satisfied, the outdoor unit
compressor will turn off, 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. This code will be shown on the indoor display
board or a flashing LED will appear on the outdoor PCB.
Indoor Unit
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 PCB will illuminate the display, indicating the
set temperature and current status of the unit. The PCB will
signal the stepper motor to open the louver to either a sta-
tionary 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.
Indoor Temperature sensors
The indoor unit has two sensors that provide temperature in-
formation to the main board. An indoor ambient temperature
sensor and pipe 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 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 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. De-
pending 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 as damage
to the meter may result.
If the room temperature is less than the set temperature, yet
higher than 2°F below the set temperature, the system will
adjust the speed of the compressor automatically.
The outdoor unit main board also controls the position of
the EEV (Electronic Expansion Valve) to regulate the flow of
refrigerant to the indoor unit evaporator coil.
System Power
