Expansion Valve (Txv) System - Maytag Amana H Series Installation Instructions Manual

Superheat Adjustment
NOTE: Superheat adjustments should not be made
until in door ambient conditions have stabilized.
This could take up to 24 hours depending on
indoor temperature and humidity. Before checking
superheat run the unit in cooling for 10-15 minutes
or until refrigerant pressues stabilize. Use the
fol lowing guidelines and methods to check unit
operation and ensure that the refrigerant charge
is within limits.
For TXV systems, to adjust superheat, unscrew the cover
from the expansion valve, locate the adjustment screw, and
turn it clockwise (in) to increase superheat or counterclock-
wise (out) to decrease superheat. It is recommended to
make small adjustments at a time, 1/8-1/4 turn increments.
Replace adjustment cap. Wait a minimum of 10 minutes.

Expansion Valve (TXV) System:

Two Speed Application (*PCH36041)
Run the unit on low stage cooling for 10 minutes until
refrigerant pressures stabilize. Follow the guideline and
methods below to check unit operation and ensure that the
refrigerant charge is within limits. Charge the unit on low
stage.
1. Purge gauge lines. Connect service gauge manifold
to access fittings. Run system at least 10 minutes to
allow pressure to stabilize.
2. Temporarily install thermometer on liquid (small) line
near liquid line access fitting with adequate contact
and insulate for best possible reading.
3. Check subcooling and superheat. Two stage systems
running on low stage with TXV application should
have a subcooling and superheat within the range
listed on the chart.
a. If subcooling and superheat are low, adjust TXV
superheat, then check subcooling.
NOTE: To adjust superheat, turn the valve stem
clockwise to increase and counter clockwise to
decrease.
b. If subcooling is low and superheat is high, add
charge to raise subcooling then check superheat.
c. If subcooling and superheat are high, adjust TXV
valve superheat, then check subcooling.
d. If subcooling is high and superheat is low, adjust
TXV valve superheat and remove charge to lower
the subcooling.
NOTE: Do NOT adjust the charge based
on suction pressure unless there is a gross
undercharge.
4. Disconnect manifold set, installation is complete.
Checking Subcooling
NOTE: Units with a TXV should be charged to
Subcool ing only.
SUBCOOLING FORMULA = SATURATED LIQUID LINE
TEMPERATURE - LIQUID LINE TEMPERATURE
EXAMPLE:
a. Liquid Line Pressure = 417 PSI
b. Corresponding Temp. = 120°F
c. Thermometer on Liquid line = 109°F.
To obtain the amount of subcooling, subtract 109°F
from 120°F. The difference is 11° subcooling. See
the specification sheet or technical information
manual for the design subcooling range for your
unit.
Design superheat @ 95°F outdoor
ambient temperature
Model
GPCH32441
APCH32441
*PCH33041
*PCH33641
*PCH34241
*PCH34841
Design superheat @ 82°F outdoor
ambient temperature
*PCH36041
Design superheat @ 95°F outdoor
ambient temperature
Model
*PHH32441
*PHH33041
*PHH33641
*PHH34241
*PHH34841
*PHH36041
14
*PCH3
Superheat Subcooling
± 2°F ± 2°F
17 -
15 -
17 -
9 -
16 -
8 -
6 7
*PHH3
Superheat Subcooling
± 2°F ± 2°F
4 -
3 -
4 -
3 -
14 -
3 -