Introduction To System; Specifications For Proper Operation Should Be Followed; Fundamental Theory Of How System Works - Haier HSU09VHG(DB)-W Service Manual

Introduction to System

Single Zone Ductless Split System Heat Pumps feature a wall
mounted indoor fan/evaporator unit that receives refrigerant
from an inverter driven variable speed outdoor condensing
unit. The system operation is controlled with a remote
control.
The outdoor unit features a variable speed rotary
compressor, EEV metering device and DC fan motor. These
systems use R410A refrigerant and PVE oil. The outdoor units
are 208/230 volt rated systems. They come factory charged
for up to 25 ft. of interconnecting piping.
The indoor units are wall mounted type. They feature a DC
blower motor and a DC louver motor. The unit has a room
temperature sensor and an evaporator tube temperature
sensor. The wall unit is powered by voltage from the outdoor
unit.
Specifications for proper operation should be followed
• The systems are designed to operate in temperature
ranges of 60°F to 86°F in cooling mode and 60°F to 86°F in
heat mode.
• PVE oil is non reactive to water and will not go into
Hydrolysis. There is no need to add a refrigeration drier
when servicing or installing this system.
• The indoor wall mounted unit receives operating voltage
and communication data signals on #14 AWG wire that
connects between the indoor and outdoor units. There
should not be any splices in the field wiring that goes
between terminals 1, 2, 3 and 4. A splice in these wires may
cause the system to lose communication between the
indoor and outdoor units. The system will then display an
error code E7.
• The systems come with enough factory charge for up to
25 feet of connecting refrigeration tubing. The tubing
connects using flare type fittings at both the indoor and
outdoor units. Tubing must be sized per the specifications.
Both lines must be insulated. The only method of checking
charge or adjusting charge is by weight method explained in
this manual. (No exceptions.)
• The condensate system is a gravity type. A field installed
condensate pump may be added to the system. Always
follow the manufacturer's installation instructions when
installing a condensate pump.
• Proper clearances at both indoor and outdoor units must be
maintained. Improper clearances cause system conditions
that include high refrigerant pressure, low refrigerant
pressure and indoor coil freezing problems.
Fundamental Theory Of How System Works
The indoor unit will sense room temperature at the point
where the wall unit is installed. The indoor fan will run
continuously when placed in heating or cooling mode
operation and will not cycle on and off with the outdoor
unit. If it did, room temperature could not be sensed or
Introduction
maintained.
The inverter compressor system in the outdoor unit will vary
the refrigerant flow and indoor air volume levels to match
the cooling requirement inside the conditioned space. If an
abnormal condition is detected by the system's sensors, the
system has the ability to take reactive measures.
The amount of refrigerant flow and associated capacity
generated by the system will be determined by how fast the
system's variable speed rotary compressor is pumping. The
compressor operating speed requirement is determined by
the difference between the conditioned space temperature
versus the set point established by the homeowner's remote
control.
If a large amount of capacity is needed, the compressor will
operate at a high frequency speed. As the need for capacity
reduces and the temperature of the room nears set point,
the compressor will slow down. When set point has been
reached, the compressor will shut off but the indoor fan
will continue to operate. Once a difference in temperature
is sensed between remote control set point temperature
and room temperature, the compressor will restart at a new
calculated speed.
If a system sensor determines there is a need to adjust
the frequency signal to prevent a system malfunction,
the compressor frequency may be over ridden and a new
frequency established. It should be noted that the frequency
signal level that is sent to the compressor cannot be
determined by a servicing technician.
In this manual, system components, operation, sensor
functions and diagnostic procedures will be explained in
greater detail.
INTRODUCTION PAGE 5