SERVICING
51
NOTE: R410A should be drawn out of the storage container
or drum in liquid form due to its fractionation properties, but
should be "Flashed" to its gas state before entering the
system. There are commercially available restriction devices
that fit into the system charging hose set to accomplish this.
DO NOT
charge liquid R410A into the compressor.
4. With the system still running, close the valve on the
charging cylinder. At this time, you may still have some
liquid refrigerant in the charging cylinder hose and will
definitely have liquid in the liquid hose. Reseat the liquid
line core. Slowly open the high side manifold valve and
transfer the liquid refrigerant from the liquid line hose and
charging cylinder hose into the suction service valve port.
CAREFUL: Watch so that liquid refrigerant does not
enter the compressor.
Final Charge Adjustment
The outdoor temperature must be 60°F or higher. Set the
room thermostat to COOL, fan switch to AUTO, and set the
temperature control well below room temperature.
After system has stabilized per startup instructions, com-
pare the operating pressures and outdoor unit amp draw to
the numbers listed on the performance label on the outdoor
unit. If pressures and amp draw are too low, add charge. If
pressures and amp draw are too high, remove charge. Check
subcooling and superheat as detailed in the following sec-
tion.
5. With the system still running, remove hose and reinstall
both valve caps.
6. Check system for leaks.
Do not charge a remote condensing unit with a non-matching
evaporator coil, or a system where the charge quantity is
unknown. Do not install or charge R410A condensers matched
with coils having capillary tubes or flow control restrictors.
ARI rated Coil combinations with thermostatic expansion
valves (TEV's) should be charged by subcooling. See
"Checking Subcooling and Superheat" sections in this manual.
Subcooling values for "Ultron" system are found in the
Technical Information manuals for "Ultron" outdoor units.
Due to their design, Scroll compressors are inherently more
tolerant of liquid refrigerant.
NOTE: Even though the compressor section of a Scroll
compressor is more tolerant of liquid refrigerant, continued
floodback or flooded start conditions may wash oil from the
bearing surfaces causing premature bearing failure.
S-104 CHECKING COMPRESSOR EFFICIENCY
The reason for compressor inefficiency is broken or damaged
scroll flanks on Scroll compressors, reducing the ability of
the compressor to pump refrigerant vapor.
The condition of the scroll flanks is checked in the following
manner.
1. Attach gauges to the high and low side of the system.
2. Start the system and run a "Cooling Performance Test.
If the test shows:
a. Below normal high side pressure.
b. Above normal low side pressure.
c. Low temperature difference across coil.
d. Low amp draw at compressor.
And the charge is correct. The compressor is faulty - replace
the compressor.
S-105A PISTON CHART FOR SSX14 & ASX14
UNITS
Remote
Condenser
Orifice Size
SSX140181
0.049
SSX140241
0.057
SSX140301
0.063
SSX140361
0.067
SSX140421
0.074
SSX140481
0.079
SSX140601
0.088
ASX140181A
0.049
ASX140241A
0.057
ASX140301A
0.063
ASX140361A
0.067
ASX140421A
0.074
ASX140481A
0.079
ASX140601A
0.088
S-105B THERMOSTATIC EXPANSION VALVE
The expansion valve is designed to control the rate of liquid
refrigerant flow into an evaporator coil in exact proportion to the
rate of evaporation of the refrigerant in the coil. The amount of
refrigerant entering the coil is regulated since the valve
responds to temperature of the refrigerant gas leaving the coil
(feeler bulb contact) and the pressure of the refrigerant in the
coil. This regulation of the flow prevents the return of liquid
refrigerant to the compressor.
The illustration below shows typical heatpump TXV/check
valve operation in the heating and cooling modes.