Trane 4NXCA024AC3HCA Installer's Manual page 12

Before starting, insure the
blower wheel, indoor and outdoor
coils are clean.
Is sub cooling at the
YES
outdoor unit between
8 to 12F?
Verify line set is
sized properly NO
for application
NO
Is sub cooling less
YES
than 8F?
NO
Confirm that
charge is
correct.
Trane Inc.
6200 Troup Highway
Tyler, TX 75707
For more information contact
your local dealer (distributor)
Is superheat
YES
< 5F?
NO
Is superheat
< 20F?
NO
Is the liquid line
temperature at indoor
coil within 8F of outdoor
liquid line temperature?
YES
Is indoor
temperature more NO
than 85F?
YES
The system is running at max
capacity and this may be
causing the High superheat.
Wait until indoor temperature
is less than 80F and check
superheat again.
Confirm that charge
is correct and look
for dirty or restricted
outdoor coil.
Since the manufacturer has a policy of continuous product and product data improvement, it reserves the
right to change design and specifications without notice.
Is air flow at least
350 CFM per ton?
YES
YES
Remove sensing bulb from the
suction line. Measure superheat
at indoor coil while holding the
bulb in bare hand for one minute.
Does superheat decrease?
NO
Correct air
NO flow
problem
Measure superheat at indoor coil
YES
while placing the bulb in an ice
and water bath for one minute.
Does superheat increase?
NO
Replace the
TXV
TXV is OK
YES
06/13