Carrier AGATWNPME01B, Installation Instructions Manual, Page: 6 / 22

AGATWNPME01B: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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from one furnace and the left side knockout from the other furnace.
The furnace with the right side knockout removed will become the
Main furnace in side-by-side applications. In back-to-back
applications, either furnace can be the Main furnace.
2. For side-by-side applications insert one snap bushing through each
7/8 in. (22 mm) knockout.
3. Position furnaces against each other on common return-air plenum,
see Fig. 4 . For side-by-side installations, adjust and shim each
furnace to align 7/8 in. (22 mm) knockout in blower compartment,
which will be used for wire routing between furnaces.
4. Drill two 1/8 in. (3 mm) holes, approximately 1 in. (25 mm) below
discharge air flange, from inside top of discharge opening and
through both furnaces, see Fig. 9 .
5. Drive one factory-supplied No. 6 x 3/4 in. (19 mm) LG screw
through each hole and tighten until furnaces are secure and foam
strips have sealed gap between furnaces.
6. Bend or remove flanges on supply air outlet of furnace as shown in
furnace installation instructions.
7. Install indoor coil(s) and/or common supply plenum on supply air
outlet of furnace. Seal all duct connections to furnace with code
approved tape or sealant.
8. Connect common return plenum on furnace. Seal all duct
connections to furnace with code approved tape or sealant.
9. Refer to the furnace installation instructions to complete the
remaining furnace installation.
A93539
Fig. 9 – Furnaces Together at Discharge Opening
DOWNFLOW INSTALLATIONS
1. Remove the 7/8 in. (22 mm) knockout in the mating side of each
furnace blower compartment. Remove one right side knockout
from one furnace and the left side knockout from the other furnace.
The furnace with the right side knockout removed will become the
Main furnace in side-by-side applications. In back-to-back
applications, either furnace can be the Main furnace.
2. Insert one snap bushing through each 7/8 in. (22 mm) knockout.
3. Bend or remove flanges on supply air outlet of furnace as shown in
furnace installation instructions
4. Position furnaces in the downflow position on the entering air-side
of indoor coils and or common supply plenum. If no approved
cased indoor coil is used, install the furnaces on accessory
combustible floor bases. For side-by-side installations, adjust and
shim each furnace to align unused 7/8 in. (22 mm) knockout in
blower compartment, which will be used for wire routing between
furnaces.
5. Drill two 1/8 in. (3 mm) holes, approximately 1 in. (25 mm) below
return air flange, from inside top of return air opening and through
both furnaces, see Fig. 10 .
6. Drive one factory-supplied No. 6 x 3/4 in. (19 mm) LG screw
through each hole and tighten until furnaces are secure and foam
strips have sealed gap between furnaces.
7. Connect common return plenum to furnaces. Seal all duct
connections to furnace with code approved tape or sealant.
A02219A
Fig. 10 – Attaching Furnaces Together at Return Air Opening
8. Follow individual furnace installation instructions for downflow
applications. This includes, but not limited to: condensate trap,
condensate/inducer housing tubing, pressure switch tubing venting
and electrical connections.
9. Go to Connect Electrical Components
HORIZONTAL INSTALLATION
General
When twinning furnaces in the horizontal position, consideration must
be made to the type of building construction. Attic floors should be
constructed to support normal live and dead loads of the furnaces and the
person(s) servicing them. Trusses, wood and metal are engineered for
specific applications, and may not support the weight of two (2) furnaces
suspended from the top chords or by the bottom chords of the trusses.
Long horizontals spans may flex or sag, resulting in damage to the
building. Contact the truss manufacturer for additional design and
engineering assistance. Do not suspend condensing furnaces with straps
or suspend furnaces from roof decking.
On condensing furnaces, allow a minimum of 2 in. (51 mm) clearance
below the unit for condensate drain connections.
WARNING
!
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire, personal
injury or death.
DO NOT use the back of the furnace for return-air duct connections as
limit cycling and unsafe operation will occur.
SCREW DISCHARGE
OPENINGS TOGETHER
WARNING
!
UNIT DAMAGE AND FIRE HAZARD
Failure to follow this warning could result in unit damage, fire, personal
injury or death.
DO NOT use the back or side of the furnace for return-air duct
connections as limit cycling and unsafe operation will occur.