These furnaces are equipped with a manual reset limit switch
in burner box. This switch opens if an overheat condition
(rollout) occurs in burner enclosure. Correct inadequate
combustion-air supply or improper venting condition and
reset switch. DO NOT jumper this switch.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press button to reset switch.
Step 2—Select Setup Switch Positions
AIR CONDITIONING (A/C) SETUP SWITCHES
The air conditioning setup switches are used to match furnace
airflow to cooling unit used. This furnace will provide 400 CFM
per selected air conditioning tonnage.
To set the desired cooling airflow:
1. Remove main furnace door and blower access panel.
2. Locate A/C setup switches on control center. (See Fig. 25.)
3. Determine air conditioning tonnage used.
4. Use Table 8 or wiring schematic to determine proper setup
position of A/C switches. (See Fig. 24 and 47.)
NOTE: Excessive airflow caused by improper A/C switch setup
may cause condensate blow off in cooling mode.
5. Replace main furnace door and blower access panel.
NOTE: EAC-1 terminal is energized whenever blower operates.
HUM terminal is only energized when gas valve is energized.
CONTINUOUS FAN (CF) SETUP SWITCHES
The CF setup switches are used to select desired airflow when
thermostat is in continuous fan mode. This setup feature allows
continuous fan airflow to be adjusted. To set desired continuous
fan airflow:
1. Remove main furnace door and blower access panel.
2. Locate CF setup switches on control center. (See Fig. 25.)
3. Determine desired continuous fan airflow.
4. Use Table 9 or wiring schematic to determine proper setup
position of CF switches. (See Fig. 24 and 48.)
NOTE: The CF switches are factory set to provide continuous fan
airflow equal to low-heat mode.
5. Replace main furnace door and blower access panel.
SETUP SWITCHES (SW)
The control center has 8 setup switches that may be set to meet the
application requirements. Position these setup switches for the
appropriate requirement.
1. Remove main furnace door and blower access panel.
2. Locate setup switches on control center. (See Fig. 25.)
3. See Table 10 for setup switch description. (See Fig. 24 and
48.)
4. Replace main furnace door and blower access panel.
NOTE: If a bypass humidifier is used, setup switch SW-3 (BPH)
should be in ON position. This prevents nuisance limit trips caused
by the increased temperature in return air resulting from bypass.
NOTE: If modulating dampers are used, setup switch SW-5 (MZ)
should be in ON position. This allows furnace control center to
compensate for modulating dampers. The control re-calibrates for
new system static conditions once every minute while operating in
low-heat or continuous fan modes.
Step 3—Prime Condensate Trap With Water
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has 2 internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 48.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 49.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
Table 8—Air Conditioning (A/C) Airflow Setup Switch Position
AIR
CONDITIONER
(TONS)
CFM AIRFLOW
A/C SETUP
SWITCH POSITION
ALLOWABLE FURNACE MODEL SETUP
A/C-1 A/C-2 A/C-3 040-14 060-14 080-14 080-20 100-20 120-20
Default
1200 or
2000
OFF OFF OFF
3 Tons
1200 CFM
3 Tons
1200 CFM
3 Tons
1200 CFM
5 Tons
2000 CFM
5 Tons
2000 CFM
5 Tons
2000 CFM
1-1/2 600 ON OFF OFF X X X ———
2 800OFFONOFFXXXXXX
2-1/2 1000 ON ON OFF XXXXXX
3 1200 OFF OFF ON XXXXXX
3-1/2 1400 ON OFF ON XXXXXX
4 1600 OFF ON ON ——— XXX
5 2000 ON ON ON ———XXX
X—Indicates allowable selection.
Fig. 47—Example of Setup Switch in OFF Position
A95198
1
OFF
37
To Next Page
Loading...
