Indoor Unit Technical Overview - Cassette - Haier AW07LC2VHA Technical Overview

Indoor Unit Technical Overview
Evaporator
Coil
Display
6
Vertical Louvers
Stepper Motor
The wall mounted units act as evaporator coils during cooling
mode and condenser coils during heating mode. These units
have gravity condensate drain systems. If a condensate pump
is needed, it must be field provided and mounted external to
the indoor unit.
The wall mount unit is shipped with a wireless
controller.
1
1 Power to operate the indoor unit comes from the
electrical line voltage terminal block at the outdoor
unit. The wiring includes 4 wires: 1, 2, 3 and ground.
Wires 1 and 3 complete the data path. These wires
should always be 14 gauge AWG Stranded type wire.
Splices in wires 1 or 3 may cause communication
errors.
2
2
The indoor unit features a multi-speed blower motor
that will change speed to match the capacity demand from
3
3
the outdoor unit. Separate motors located in the indoor
unit control the operation of the motorized louvers. All of the
louver motors are controlled via commands received from the
remote control. The blower motor is controlled by both the
remote control and by commands from the outdoor unit ECU.
Refer to the Remote Control Information in the Reference
section for louver control/remote procedures.
PAGE 34
INDOOR UNIT TECHNICAL OVERVIEW
Indoor Wall Mount Unit Components
5
Return Air
Temperature Sensor
4
Pipe
Sensor
3
Unlike typical air handlers found in the US market, these
units have metering devices located in the outdoor unit. The
metering devices are EEV type that are controlled by the
outdoor unit ECU.
Temperature sensors located within the wall mount
unit include a pipe temperature sensor and a return air
temperature sensor.
to sense the temperature of the indoor coil in both cooling
and heating modes.
temperature of the air being drawn into the wall mounted unit
from the conditioned space. The operating functions of these
sensors is explained in the Temperature Sensor Function
section of this manual.
mode, room temperature and diagnostic code information.
The diagnostic code information shown on the indoor unit will
NOT be the same code that is displayed on the outdoor unit.
When servicing a diagnostic error, compare the indoor unit
code to the outdoor unit code to make diagnostic decisions.
Codes that relate to outdoor unit problems should use the
outdoor unit display information as priority.
functions of the indoor unit. All control decisions are made
by the outdoor unit ECU. The indoor board has some limited
diagnostic capability which will be covered in this manual.
TECHNICAL OVERVIEW
4
4 The pipe temperature sensor is used
5
The return air sensor senses the
5
6
6
The indoor unit has a display that communicates system
7
7
The indoor unit circuit board controls the switching
Control
7
Board
Terminal 1
Block
Fan
2
Motor
Horizontal Louver
3
Stepper Motor