Trane Oxbox J4HP4018A1 Installation Instructions Manual page 19

This coil comes with a factory installed piston metering device. See Table 1 for factory installed piston
size. Some system combinations will require a different sized piston to be field installed.
Contact your local parts center to order the appropriate MAYORIACHP piston kit for your system
combination.
Use Table 3 for TXV kit part numbers.
A TXV may be required to achieve minimum efficiency ratings or for long refrigerant line set
applications. Reference AHRI for system combination ratings.
Reference Table 4 to charge the system by superheat when using a piston. Reference the outdoor unit
installation guide to change the system by subcooling when using a TXV.
Table1. Factory installed piston size for each model.
Model
J4AH4E24A1A00AA
J4AH4E36A1B00AA
J4AH4E60A1C00AA
J4AH6E60A1C00AA
Table 2 . Piston size for system combination.
Outdoor Unit Model
J4HP4018A1
J4AC4018A1
J4AC4024A1
J4HP4024A1
J4HP4024A1
J4HP4030A1
J4AC4030A1
J4AC4036A1
J4HP4036A1
J4AC4036A1
J4HP4042A1
J4AC4042A1
J4HP4048A1
J4HP4060A1
J4HP6060A1
50 52 56 58
X
Indoor Unit Model
J4AH4E24A1A00A
050 factory installed
J4AH4E36A1B00A
068 factory installed
J4AH4E60A1C00A
090 factory installed
J4AH6E60A1C00A
090 factory installed
63 65 68 70
X
Piston Size
18
73 75 76 83
0.050
0.052
0.058
0.058
0.058
0.065
0.065
0.073
0.073
0.073
0.075
0.075
0.083
0.090
0.090
90
X
X