System Operation - Maytag Amana SXV9 Series Service And Troubleshooting

SYSTEM OPERATION

This section gives a basic description of Air Conditioner
condenser unit operation, its various components and their
basic operation. Ensure your system is properly sized for
heat gain and loss according to methods of the Air Condi-
tioning Contractors Association (ACCA) or equivalent.
CONDENSING UNIT
The ambient air is pulled through the Air Conditioner con-
denser coil by a direct drive propeller fan. This air is then
discharged out of the top of the cabinet. These units are
designed for free air discharge, so no additional resistance,
like duct work, shall be attached.
The gas and liquid line connections on present models are
of the sweat type for field piping with refrigerant type cop-
per. Front seating valves are factory installed to accept the
field run copper. The total refrigerant charge for a normal
installation is factory installed in the Air Conditioner con-
denser unit.
*SXV9 models are available in 2 through 5 ton sizes and
use R-410A refrigerant. They are designed for 208/230 volt
single phase applications.
*SXV9 R-410A model units use a Daikin rotary compres-
sor. These models are ComfortBridge™ and ComfortNet™
ready.
There are a number of design characteristics which are
different from the traditional compressors.
*SXV9 models use "FVC50K" which is NOT compatible
with mineral oil based lubricants like 3GS. "FVC50K" oil
(required by the manufacturer) must be used if additional oil
is required.
COOLING
The refrigerant used in the system is R-410A. It is a clear,
colorless, non-toxic and non-irritating liquid. R-410A is a
50:50 blend of R-32 and R-125. The boiling point at atmo-
spheric pressure is -62.9°F.
A few of the important principles that make the refrigeration
cycle possible are: heat always flows from a warmer to a
cooler body. Under lower pressure, a refrigerant will absorb
heat and vaporize at a low temperature. The vapors may
be drawn off and condensed at a higher pressure and
temperature to be used again.
The indoor evaporator coil functions to cool and dehumidify
the air conditioned spaces through the evaporative process
taking place within the coil tubes.
NOTE: The pressures and temperatures shown in the
refrigerant cycle illustrations on the following pages are
6
for demonstration purposes only. Actual temperatures
and pressures are to be obtained from the "Expanded
Performance Chart".
Liquid refrigerant at condensing pressure and temperatures
leaves the outdoor condensing coil through the drier and is
metered into the indoor coil through the metering device.
As the cool, low pressure, saturated refrigerant enters the
tubes of the indoor coil, a portion of the liquid immediately
vaporizes. It continues to soak up heat and vaporizes as it
proceeds through the coil, cooling the indoor coil down to
about 48°F.
Heat is continually being transferred to the cool fins and
tubes of the indoor evaporator coil by the warm system air.
This warming process causes the refrigerant to boil. The
heat removed from the air is carried off by the vapor.
As the vapor passes through the last tubes of the coil, it
becomes superheated. That is, it absorbs more heat than is
necessary to vaporize it. This is assurance that only dry gas
will reach the compressor. Liquid reaching the compressor
can weaken or break compressor valves.
The compressor increases the pressure of the gas, thus
adding more heat, and discharges hot, high pressure
superheated gas into the outdoor condenser coil.
In the condenser coil, the hot refrigerant gas, being
warmer than the outdoor air, first loses its superheat by
heat transferred from the gas through the tubes and fins
of the coil. The refrigerant now becomes saturated, part
liquid, part vapor and then continues to give up heat until
it condenses to a liquid alone. Once the vapor is fully
liquefied, it continues to give up heat which subcools the
liquid, and it is ready to repeat the cycle.
The inverter system can stop the compressor or outdoor
fan to protect the unit. The inverter system can run higher
compressor speed than required from thermostat to recover
compressor oil that flows.
SYSTEM STARTUP TEST
NOTICE: On initial power start-up, the outdoor unit will dis-
play code E11, signaling that initial SYSTEM test must be
run. Follow the instructions BELOW to initiate and complete
the testing.
A system verification test is now required to check the
equipment settings and functionality.
Inverter units are tested by any of the following methods:
• Setting the "SUt" menu (System verification test) to ON
through the indoor unit control board push buttons.
• Setting the System verification test menu of mode dis-
play screen-4 to ON through the outdoor unit control
board push buttons.
• Through the CoolCloud HVAC phone application.