Carrier 320720---751 THRU ---761 installation instructions Two-Stage, Two-Speed and Fixed-Capacity

COMBUSTION-AIR

INTAKE

CONNECTION

BURNER

PRIMARY HEAT	BURNER
EXCHANGER	ENCLOSURE
(BEHIND CELL
INLET PANEL)

GAS VALVE	ENCLOSURE
AUXILIARY	PRIMARY HEAT
JUNCTION BOX	EXCHANGER
VENT OUTLET	(BEHIND CELL
	INLET PANEL)
CONDENSING
	CAP AND
HEAT
	CLAMP
EXCHANGER
	(UNUSED
(BEHIND CELL
	DRAIN
INLET PANEL)
	CONNECTION)
PRESSURE
SWITCHES	VENT OUTLET
INDUCER MOTOR	CONTROL
CONDENSATE	CENTER
	BLOWER
TRAP
MOTOR AND	ACCESS PANEL
	SAFETY
BLOWER	INTERLOCK
ASSEMBLY	SWITCH

AIR FILTER AND

RETAINER

COMBUSTION-

AIR INTAKE

CONNECTION

AUXILIARY

JUNCTION BOX

VENT OUTLET

INDUCER MOTOR

WIRE

CONNECTOR

CONDENSING

HEAT

EXCHANGER

(BEHIND CELL

INLET PANEL)

INDUCER

HOUSING

DRAIN TUBE

CONDENSATE

TRAP

AIR FILTER

AND RETAINER

GAS VALVE

CAP AND CLAMP (UNUSED DRAIN CONN.)

INDUCER MOTOR

VENT

OUTLET

PRESSURE

SWITCHES

CONTROL

CENTER

BLOWER

ACCESS

PANEL

SAFETY

INTERLOCK

SWITCH

MOTOR AND BLOWER ASSEMBLY

320720

A01026

Fig. 1 - Two-Stage, Two-Speed and Fixed-Capacity

Model(s) in Upflow Orientation

Remove Inducer Assembly

1.If not previously disconnected, disconnect inducer motor wire connector at quick-connect.

2.If not previously disconnected, disconnect pressure switch wires.

3.Remove collector box pressure switch tube from pressure switch.

4.Remove four screws attaching inducer housing to cell pan- el.

NOTE: Inducer housing, inducer motor, and pressure switch(es) should be removed as 1 assembly.

Install Primary Cell Inlet Panel

1.Remove four screws attaching condensing heat exchanger assembly to primary cell inlet panel.

2.Remove screws attaching primary cells to primary cell in- let panel.

3.Remove main limit and shield from primary cell inlet pan- el. Note orientation of shield and direction of main limit for reassembly.

4.Remove primary cell inlet panel by lifting panel off con- densing heat exchanger collector box.

5.Slide new inlet cell panel over condensing heat exchanger collector box.

6.Attach primary cell inlet panel to primary cells by doing the following:

a.Center primary cell inlet panel over primary cell open- ings.

b.Use an awl to align holes and start ALL screws (provided in kit) in primary cells.

c.After all screws are started, check position of fiberglass gasket and tighten screws in cells.

7.Install main limit and shield in primary cell inlet panel.

A93407

Fig. 2 - Variable-Speed Model in Upflow Orientation

NOTE: Visually check location of main limit and shield to ensure shield is not touching primary cells. If shield is touching, short cycling of limit will occur.

8.Reinstall condensing heat exchanger assembly to primary cell inlet panel.

Reinstall Inducer Assembly

1.Inspect connector box gasket where inducer housing will mate.

NOTE: If gasket is damaged in any way, it must be repaired. To repair, apply a small bead of G.E. RTV 162, G.E. 6702, or Dow-Corning RTV 738 to damaged gasket area. Apply sealant releasing agent such as PAM cooking spray or equivalent (must not contain corn nor canola oil, halogenated hydrocarbons or aromatic content to prevent inadequate sealing) to inducer housing mating surface.

2.Attach inducer assembly to cell panel by aligning four screws through inducer housing spacers. Tighten screws to secure.

3.Attach collector box pressure switch tube to pressure switch. See tubing diagram of furnace for proper location attachment.

4.If control was removed from furnace with whole cell panel assembly, reconnect inducer motor wire connector at quick-connect.

5.If control was removed from furnace with whole cell panel assembly, reconnect pressure switch wires. Refer to wiring diagram on furnace for proper attachment.

Reinstall Burner Enclosure Assembly

1.Position burner enclosure gasket between the burner box and inlet cell panel and secure burner box on inlet cell panel using screws removed earlier.

2.Connect pressure tube to gas valve.

3.Inspect gasket, then install intake housing on burner en- closure.

3