Downflow Installation; Bottom Return Air Inlet; Horizontal Installation; Suspended Unit Support - Carrier 58CTA Installation And Service Instructions Manual

⁄ "
5
16
⁄
5
⁄ "
3
1
4
⁄ "
5
16
⁄ "
1 3
4
⁄
3
1
4
Fig. 10—Leveling Legs

DOWNFLOW INSTALLATION

NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following 3
accessories are used:
• Special Base, KGASB
• Cased Coil Assembly Part No. CD5 or CK5
• Coil Box Part No. KCAKC
1. Determine application being installed from Table 4.
2. Construct hole in floor per Table 4 and Fig. 11.
3. Construct plenum to dimensions specified in Table 4 and Fig.
11.
4. If downflow subbase, KGASB is used, install as shown in Fig.
12. If Coil Assembly Part No. CD5 or CK5 or Coil Box Part
No. KCAKC is used, install as shown in Fig. 13.
NOTE: It is recommended that the perforated supply-air duct
flanges be completely folded over or removed from furnace when
installing the furnace on a factory-supplied cased coil or coil box.
To remove the supply-air duct flange, use wide duct pliers or hand
seamers to bend flange back and forth until it breaks off. Be careful
of sharp edges. (See Fig. 14.)

Bottom Return Air Inlet

These furnaces are shipped with bottom closure panel installed in
bottom return-air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove 2 screws holding bottom filler
panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
"
16
⁄ "
3
1
4
⁄ "
5
16
"
A02071

HORIZONTAL INSTALLATION

FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in dangerous
operation, serious injury, death, or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control opera-
tion will be adversely affected. Never connect return-air ducts
to the back of the furnace.
The furnace can be installed horizontally in an attic or crawl space
on either the left-hand (LH) or right-hand (RH) side. The furnace
can be hung from floor joists, rafters or trusses or installed on a
non-combustible platform, blocks, bricks or pad.
Suspended Furnace Support
The furnace may be supported under each end with threaded rod,
angle iron or metal plumber's strap as shown. (See Fig. 15 and 16.)
Secure angle iron to bottom of furnace as shown. Heavy-gauge
sheet metal straps (plumber's straps) may be used to suspend the
furnace from each bottom corner. To prevent screws from pulling
out, use 2 #8 x ¾-in. screw into the side and 2 #8 x ¾-in. screw in
the bottom of the furnace casing for each strap. (See Fig. 15 and
16.)
→
If the screws are attached to ONLY the furnace sides and not the
bottom, the straps must be vertical against the furnace sides and
not pull away from the furnace sides, so that the strap attachment
screws are not in tension (are loaded in shear) for reliable support.
Platform Furnace Support
Construct working platform at location where all required furnace
clearances are met. (See Fig. 2 and 17.) For furnaces with 1-in.
clearance requirement on side, set furnace on non-combustible
blocks, bricks or angle iron. For crawlspace installations, if the
furnace is not suspended from the floor joists, the ground under-
neath furnace must be level and the furnace set on blocks or bricks.

Roll-Out Protection

Provide a minimum 17-3/4" X 22" piece of sheet metal for flame
roll-out protection in front of burner area for furnaces closer than
12 inches above the combustible deck or suspended furnaces
closer than 12 inches to joists. The sheet metal MUST extend
underneath the furnace casing by 1 in. with the door removed.
The bottom closure panel on furnaces of widths 17-1/2 in. and
larger may be used for flame roll-out protection when bottom of
furnace is used for return air connection. See Fig. 17 for proper
orientation of roll-out shield.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return-air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove 2 screws holding bottom filler
panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.

Side Return Air Inlet

These furnaces are shipped with bottom closure panel installed in
bottom return-air opening. This panel MUST be in place when side
return air inlet(s) are used without a bottom return air inlet.
11