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18-AD37D1-1-EN
Installer’s Guide
I. METERING DEVICE
A4MX
1.5-4 ton coils include a factory installed orifice.
Orifice size may need to be changed depending on the equip-
ment match. See outdoor unit for more information.
A4MX
5-ton coils are supplied with an internally-checked,
non-bleed TXV designed for air conditioning or heat pump
operation. This factory supplied TXV is suitable for ton-
nages down to 3.5 tons. Some outdoor models may require a
start assist kit.
Factory Included Metering Device
Orifice change
The orifice is accessed by removing the front panel. Use a
back—up wrench when disconnecting the fitting. Remove
the old orifice using the wire tool supplied with the kit.
Install the new orifice and tighten fitting. Make sure to use
a back—up wrench when tightening fitting.
Note: The wire tool ships with the orifice replacement kits.
Note: This unit can be applied in both 410A and R22 appli-
cations when the correct fixed orifice is installed.
Orifice change
Use the table below to determine if the factory installed
orifice needs to be changed.
Example. The A4MXC3642AC6HAA coil comes with a 0.068
orifice installed. If the coil is matched with a 3.5 ton outdoor
unit, the orifice needs to be replaced with the included 0.077
orifice.
COIL MODEL
NOMINAL
TONS
FACTORY
INSTALLED
ORIFICE
SIZE
ADDITIONAL
INCLUDED
ORIFICE
SIZES
A4MXA1824AC6HA
2
0.057
0.052
A4MXB1832AC6HA
0.052, 0.064
A4MXA3036AC6HA
2.5
0.064
0.068
A4MXB3642AC6HA
3
0.068
0.077
A4MXC3642AC6HA
0.077
A4MXB4248AC6HA
3.5
0.077
0.082
A4MXC4248AC6HA
4
0.082
0.077
A4MXD4248AC6HA
0.077
A4MXC4260AC3HA*
5
TXV
none
A4MXD4260AC3HA*
none
* The TXV is the best option for these coils and does not require
a change regardless of outdoor model match.
Outdoor Unit
Capacity (Tons)
Indoor Unit
Orifice Size
(R-410A) (a)
Indoor Unit Fixed Orifice
Replacement Part Kit Number
1.5
0.052
BAYORIACHP0052
2
0.057
BAYORIACHP0057
2.5
0.064
BAYORIACHP0064
3
0.068
BAYORIACHP0068
3.5
0.077
BAYORIACHP0077
4
0.082
BAYORIACHP0082
(a) Sizes are for both R-410A and R-22 refrigerants.
Coil Model
Accessory TXV Kit Number
A4MXA1824AC6HA
4AYTXVH4A1830A
A4MXB1832AC6HA
A4MXA3036AC6HA
A4MXB3642AC6HA
A4MXC3642AC6HA
A4MXB4248AC6HA
4AYTXVH4A3042A
A4MXC4248AC6HA
A4MXD4248AC6HA
A4MXC4260AC3HA
A4MXD4260AC3HA
4AYTXVH4A4860A
Accessory TXV Kit
Reference the 4AYTXVH4 accessory table for TXV replace-
ment kits. See TXV kit for installation instructions.
The following TXV kits are available as part of matched
systems in the AHRI directory for when improved system
ratings are required.
TXV and Coil Matches
Orifice Size Table
Note: Install the orifice
in the orientation
shown.
