507713-01
Page 28 of 32
Issue 1623
Blower Speeds
Follow the steps below to change the blower speeds.
1. Turn off electrical power to furnace.
2. Remove blower access panel.
3. Disconnect existing speed tap at integrated control
speed terminal.
NOTE:
Termination of any unused motor leads must be
insulated.
4. Place unused blower speed tap on integrated control
“PARK” terminal or insulate.
5. Refer to blower speed selection chart on unit wiring
diagram for desired heating or cooling speed. See
Blower performance data beginning on the next page.
6. Connect selected speed tap at integrated control speed
terminal.
7. Resecure blower access panel.
8. Turn on electrical power to furnace.
9. Recheck temperature rise.
Fan Control
The fan on time of 45 seconds is not adjustable. The heat
fan off delay (amount of time that the blower operates after
the heat demand has been satisfied) may be adjusted by
changing the jumper position across the five pins on the
integrated control. The unit is shipped with a factory fan
off delay setting of 90 seconds. The fan off delay affects
comfort and is adjustable to satisfy individual applications.
Adjust the fan off delay to achieve a supply air temperature
between 90° and 110° F at the moment that the blower is
deenergized. Longer off delay settings provide lower return
air temperatures; shorter settings provide higher return air
temperatures. See Figure 37.
Thermostat Heat Anticipation
Set the heat anticipator setting (if adjustable) according to
the amp draw listed on the wiring diagram that is attached
to the unit.
NOTE:
Do not secure the electrical conduit directly to the
air ducts or structure.
Electrical
1. Check all wiring for loose connections.
2. Check for the correct voltage at the furnace (furnace
operating). Correct voltage is 120VAC ± 10%.
3.Check amp-draw on the blower motor with inner
blower panel in place.
Unit Nameplate__________ Actual _______________
HEAT FAN OFF TIME IN SECONDS
Figure 37
Other Unit Adjustments
Primary and Secondary Limits
The primary limit is located on the heating compartment
vestibule panel. The secondary limits (if equipped) are
located in the blower compartment, attached to the back
side of the blower. These auto reset limits are factory set
and require no adjustment.
Flame Rollout Switches
This manually reset switches are located on the front of the
burner box.
Pressure Switch
The pressure switch is located in the heating compartment
adjacent to the combustion air inducer. The switch checks
for proper combustion air inducer operation before allowing
ignition trial. The switch is factory set and requires no
adjustment.
Temperature Rise
After the furnace has been started, and supply and return
air temperatures have been allowed to stabilize, check the
temperature rise. If necessary, adjust the blower speed to
maintain the temperature rise within the range shown on
the unit nameplate. Increase the blower speed to decrease
the temperature. Decrease the blower speed to increase
the temperature rise. Failure to adjust the temperature rise
may cause erratic limit operation.
