J4AC3 Installation Manual

18
Step 1: Remove the screws and front coil
panel.
Step 2: Remove the rubber plugs from the
liquid and vapor lines.
Step 3: Using a back up wrench and loosen
the flow assembly. Remove the factory
installed piston Reassemble and tighten the
flow assembly. Tighten the flow assembly
to 11 (±2) ft-lb
Step 4: If replacing the preinstalled
orifice with the optional orifice, ensure the
replacement orifice is placed in the same
orientation as the preinstalled orifice before
tightening the flow assembly.
TXV-Specific Steps
Step 5: Drill a small hole in the suction line for the TXV equalizer line. The hole
must be on top as noted in the picture.
Step 6: Dry fit the TXV to the liquid line entering the coil. The valve must be in
the upright position as pictured. Keep the valve as close to the coil as possible,
although a short piece of field fabricated tubing may be needed. The TXV must
be mounted in the CORRECT direction of flow. Place the TXV equalizer line 3
to 4 mm inside the small hole drilled in the vapor line.
Step 7: Wrap the TXV and coil panel with a wet rag to prevent overheating
while brazing. Use a nitrogen flow and braze all connections.
Step 8: Allow tubing to cool and pressurize line sets with 150 PSI of nitrogen to
check braze connections and flow assembly for leaks. Make repairs as needed.
Step 9: Locate and clean a straight section of the vapor line as close to the coil
as possible. Use the supplied copper straps to secure the TXV sensing bulb on
top of the vapor line as pictured.
Step 10: Insulate the entire vapor line and sensing bulb It is also
recommended to insulate the TXV and liquid line between the valve and coil to
prevent condensation in hot humid environments.
Step 11: Replace the front coil panel and secure in place.
Step 12: Follow the steps in the installation guide for vacuum requirements and
system start up procedures.
Step 13: Allow system to run for a minimum of 10 minutes in the cooling mode.
A: For fixed orifice installation: Use the superheat charging chart to obtain
proper superheat based on indoor / outdoor conditions.
B: For TXV installation:
Charge the system to 10 degrees of subcooling.
Adjust the expansion valve to achieve 9 (± 3 degrees) of superheat.
Step 14: Allow system to run for an additional 10 minutes to verify the subcooling
and superheat reading
s.
DRILL A SMALL HOLE IN VAPOR
LINE FOR EQUALIZER TUBE
PISTON
TXV
BULB
Orifice/TXV Replacement Information
NOTE: The orifice / TXV replacement options noted in this sheet supersede those in the installation guide.
Please reference this sheet for all refrigerant metering options.
Superheat Charging Chart
Outdoor
Temp
(
ºF)
Indoor Temperature (
ºF)
Dry Bulb/Wet Bulb
95/79 90/75 85/71 80/67 75/63 70/58
115 23 16 7555
110 24 17 9555
105 26 19 11 555
100 27 21 13 755
95 29 23 16 955
90 30 25 18 12 5 5
85 32 26 20 14 8 5
80 34 28 22 17 11 5
75 35 30 24 19 13 6
70 37 32 26 21 16 10
65 38 34 29 24 19 13
60 40 36 31 27 22 17
55 41 37 33 29 25 21
System Charge Adjustment
R-410A SUBCOOLING CHARGING TABLE
OUTDOOR TEMPERATURE (°F)
82 95 115
DESIGN SUBCOOLING VALUES (°F)
10~12 8~10 5~8
Subcooling Charging (Above 55ºF Outdoor Temp.)
Note 1: Chart is based on 400 CFM/Ton indoor airflow and 50% relative
humidity. If indoor relative humidity is above 70% or below 20%, use
indoor wet bulb temperature only. Airflow range is 375 to 425 CFM/Ton.