Trane BAY4TXV1830A Assembly instructions

General Information
This TXV kit is intended only for use with the specific
models of the A4AH Air Handlers.
This kit is used to increase efficieny ratings for these
models.
NOTE: This kit is for use with 410A Regerant only.
Kit Identication
Confirm that the air handler TXV kit is approved for use
with the air handler model being installed.
Inspection
Check carefully for any shipping damage. Any damage must
be reported to, and claims made against the transportation
company immediately. Any missing parts should be reported
to your supplier at once and replaced with authorized parts
only.
Coil TXV Kit Contents
Open and inspect contents for damage or missing
items.
Each kit contains:
No. Qty Description
1 1 Expansion Valve
2 1 Teflon® O-ring
3 1 Installer's Guide (Not shown)
4 1(2) Bulb Insulation
5 1(2) Cable Tie
6 1 Sensing Bulb Strap
7 1(2) Push-in Cable Tie
INSTALLER'S
GUIDE
IMPORTANT — This Document is customer property and is to remain with this unit. Please return to service information
pack upon completion of work.
ALL phases of this installation must comply with NATIONAL, STATE AND LOCAL CODES
88-A4AH4TXV-1C-EN
Fits Coil Models:
A4AH4P18A
A4AH4P24A
A4AH4P30A
Coil TXV Kit:
BAY4TXV1830A
Figure 1
1
2
4
5
6
7

2 88-A4AH4TXV-1C-EN
COIL THERMAL EXPANSION VALVE INSTALLER'S GUIDE
Installation Instructions
1. If air handler has never been installed, go to Step 2.
If air handler has been previously installed, recover
system charge or “pump-down” system charge into
the condensing unit to comply with EPA regulations.
NOTE: Minimize the amount of movement of the liquid
and distributor tubes to prevent work hardening.
2. Using a back-up wrench, loosen mechanical fittings
on the orifice housing of the distributor.
3. Remove the cap from the equalizer port and then
REMOVE the Schrader valve from the port.
4. Remove the Teflon ® O-ring from the existing flow
control assembly. O-rings may be attached to the
TXV or the fittings.
IMPORTANT: Proper installation of TXV is critical for
preventing leaks. DO NOT oil any threads on TXV,
distributor, or liquid line ttings.
5. To install the coil TXV, install the new O-ring over the
distributor fitting (Figure 2). Hand-tighten the nut to
make sure there is proper mating of threads.Tighten
until bodies “bottom” or a definite resistance is felt.
Use a back-up wrench and tighten an additional 1/4
turn. Wrap supplied push-in cable tie around TXV
and then insert cable tie barb into coil housing hole.
IMPORTANT: Correct tightening of the nut is very
important. Under- or over-tightening may result in a
leaking connection.
6. Connect the TXV equalizer line to the equalizer
port. Hand-tighten until flare bottoms. Use a back-
up wrench to tighten securely (Figure 4).
IMPORTANT: Replacing the liquid line lter drier is
recommended if system has been commissioned. This
is not necessary if this kit is being installed on a new air
handler.
7. To avoid damaging the TXV, braze the field gas line
to the air handler gas manifold prior to attaching the
TXV bulb.
8. After completing the brazing operation, allow the
lines to cool. Attach the bulb to the gas line as
shown in figure 3.
Distributor
Fitting
Figure 2
Teon®
O-ring
TXV
Make contact tight.
• Clean the suction line
thoroughly before
clamping the bulb in
place.
• Bulb has to be mounted
in tight contact with pipe.
(TIP: Shine a flashlight
between bulb and suc-
tion line, realign the bulb
if light is visible.)
• Align the bulb with cop-
per gas line and position
at 10 or 2 o’clock.
• Pull the bulb strap tight
around the copper gas
line and bulb before
tightening the screw.
• After tightening, it should
not be possible to move
the bulb by hand.
Figure 3

9. Wrap the bulb with supplied insulation and secure
with supplied cable tie (Figure 4).
The entire length of the bulb must be in firm
contact with the gas line. The remote bulb tubing
must not be allowed to touch a surface colder
than the remote bulb location. The remote bulb
tubing must be isolated from rubbing all other
components.
CAUTION
!
Do not allow copper and aluminum materials to touch.
Maintain a minimum of .25" between copper and
aluminum material to avoid galvanic corrosion which
may lead to coil leaks.
Equalizer Line
Fitting
Position the Bulb
between 10 and 2
o'clock in-line with
copper gas line for
best results
Insulation and
Cable Tie
Copper
Aluminum
Push-in
Cable Tie
If needed, wrap copper
lines to prevent touching
aluminum and allowing
galvanic corrosion
10. Pressurize with dry nitrogen and leak test all joints
to ensure no leaks exist. Evacuate system to a
minimum of 500 microns.
11. Verify that all distributor tubes are positioned over the
drain pan to ensure distributor tubing condensate is
collected.
12. Open valves to outdoor unit if pumped-down or
charge to a minimum of 50 psig static pressure.
Start system and charge to appropriate level per the
charging method recommended in the Outdoor Unit
Installer's Guide.
Figure 4
About Trane and American Standard Heating and Air Conditioning
Trane and American Standard create comfortable, energy efficient indoor environments for residential applications.
For more information, please visit www.trane.com or www.americanstandardair.com
The manufacturer has a policy of continuous data improvement and it reserves the right to change design and specifications without notice. We are
committed to using environmentally conscious print practices.
© 2020
88-A4AH4TXV-1C-EN 19 Jun 2020
Supersedes 88-A4AH4TXV-1B-EN (October 2019)