Haier AW07EH2VHA, Service Manual

Page: 95 / 140

MEDIUM STATIC DUCTED (PRO SERIES) TECHNICAL OVERVIEW
H3
ENGLISH
Components
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Piping Temperature Sensor
The Piping Temperature Sensor senses indoor coil temperature in the cooling mode and in the heating mode. This sensor is
used for Anti Freezing and Anti Cold Blow cycles. The sensor also provides critical temperature information to the ECU that
may be used in frequency adjustments.
Condensate Pump
The Medium Static Ducted unit has a built in condensate pump. The pump is connected to the circuit board. The pump
is energized whenever the Float Switch indicates that water needs to be pumped from the cassette. The float switch
connects onto the circuit board.
The float switch and pump are located behind the removable insulated cover next to the electrical control box. The pump
is hermetically sealed and requires no maintenance. The float switch is a normally closed switch, that opens as water rises.
The float switch requires no maintenance.
Gravity Drain Ports
The indoor unit has the option for either gravity drain systems or the use of an internal condensate pump with float switch.
The pump is capable of minimal lift. If high lift is required, the water from the Medium Static Ducted unit should be pumped
to a field supplied condensate pump that is capable of high lift.
Indoor Unit Circuit Board
The indoor unit circuit board controls the switching 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.
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CN13 Float switch
CN22 Wired controller
CN41 Ambient and Coil sensors
CN4 Condensate pump
CN6 Blower motor
Terminal Block
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1. If in COOL or DRY mode: Compressor running (Thermal ON), then condensate pump is energized
• When compressor stops (Thermal OFF), condensate pump runs for an additional 5 minutes
2. If in COOL or DRY modes and compressor is running (Thermal ON) and the float switch opens for 5 minutes
•Compressor will stop, the pump will continue to run
•If the float switch does not close, error code will display and pump continues to run
•If the float switch does close, the pump will continue to run for 5 additional minutes
3. During standby (Thermal OFF) in COOL/DRY modes or in HEAT and FAN modes and float switch opens for 2 seconds,
the condensate pump is energized.
•If the float switch closes, the pump will run an additional 5 minutes
•If the float does not close, the pump continues to run and error code is displayed