Service Manual
INTRODUCTION
PAGE 5
ENGLISH
Introduction to System
Introduction
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. System operation is controlled by a hand-held remote.
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 for 18k/24k and 115 volt for
9k /12k. They are factory charged for up to 25 feet of
refrigerant piping.
The indoor section is wall mounted.
The unit has a room temperature sensor and a coil
temperature sensor that maintain room comfort.
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.
Hydrolysis. There is no need to add a refrigeration drier
when servicing or installing this system.
AWG stranded wire which connects the
indoor unit to the outdoor section. Do not splice these wires,
as a communication error may result, causing the indoor unit
to display an error code of E7.
indoor and outdoor units. Tubing must be sized per the
specifications of the unit being installed and must be
insulated. Any adjustments to the original factory charge
must be by weigh-in ONLY.
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.
. Clearances to obstructions for both indoor and outdoor
units mustbe maintained according to the installation
manual.
Fundamental Theory Of Operation
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
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
variable speed rotary compressor is pumping.Thecompressor
operating speed requirement is determined bythe difference
between the conditioned space temperatureversus the set
point established by the remote control.
If a large amount of capacity is needed, the compressor will
operate at a high 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.
Specifications for Proper Operation should be follow