Installation guide

1.
Main Burner
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Face
10-10-78
Temperature Rise Check
The blower speed MUST be set to give the correct air temperature
rise through the furnace as marked on the rating plate. Tempera-
ture rise is the difference between supply and return air tempera-
tures.
To check temperature rise,use the following procedure:
1. Place thermometers in supply and return air registers as
close to furnace as possible, avoiding direct radiant heat
from heat exchangers.
2. Operate furnace continuously for 15 minutes with all regis-
ters and duct dampers open.
3. Take reading and compare with range specified on rating
plate.
4.
If the correct amount of temperature rise is NOT obtained, it
may be necessary to change blower speed. A higher blower
speed will lower the temperature rise. A lower blower speed
will increase the temperature rise.
Changing BlowerSpeed
Electrical shock hazard.
Turn OFF power to furnace before changing speed
taps.
Failure to do so can result in personal injury and/or
death.
NOTE: The speed taps that the manufacture sets from the factory
for this product are based on a nominal 400 CFM per ton cooling
and the basic mid range on the temperature rise for heating.
Since the manufacturer cannot establish the static pressure that
will be applied to the unit, it is the responsibility of the installer
dealer/contractor to select the proper speed taps for the applica-
tion when the unit is installed.
If it is necessary to change speeds, refer to steps below.
Refer to Furnace Wiring Diagram for location of the heating
and cooling speed taps located on the electronic fan control
as well as location of unused blower motor speed leads. Use
the chart (Table 7 ) to determine the blower motor speed set-
tings.
Wire Color
Black
Orange
Blue
Red
Blower Speed Chart
Motor Speed
High
Med-High
Medium-Low
Low
2. Change the heat or cool blower motor speed by removing the
motor lead from the "Heat" or "Cool" terminal and replace it
with the desired motor speed tap from the "Unused Motor
Leads" location. Connect the wire previously removed from
the "Heat" or "Cool" terminal to the vacated "Unused Motor
Leads" terminal.
3. If the same speed must be used for both heating and cooling,
remove the undesired motor speed lead from the "Heat" or
"Cool" terminal and connect that lead to the open terminal at
"Unused Motor Leads" location. Attach a jumper between
the "Heat" and "Cool" terminals and the remaining motor
speed lead.
Note: When using the same speed for heating and cooling on
motors with (4) speed leads, it may be necessary to tape off
the terminal of the motor speed lead removed from the "Heat"
or "Cool" terminal with electrical tape if an open terminal is
not available at the "Unused Motor Leads" location.
Continuous Fan Operation
A terminal is provided on the electronic fan control located in the
circulating blower compartment for operation of the continuous
fan option. This connection is intended for the low speed motor
tap, and has a lower contact rating (8 amps) than the heat and
cool taps. When the low speed blower lead is connected to this
terminal, this will provide low speed blower operation whenever
the other two speeds (Heat or Cool) are not energized.
Thoroughly check the system after modification to ensure the
proper operation of the circulating air blower in all modes of op-
eration.
Separate speed selections for Heat, Cool, and Continuous
Fan
Connect low speed lead from circulating motor to the "Cont." ter-
minal at the electronic fan control. The appropriate motor leads
should already be connected to the "Heat" and "Cool" terminals.
Heating and Continuous Blower Speed the Same
If it is necessary to operate the heating speed and continuous
blower speed using the same blower speed, connect a jumper be-
tween the "Heat" and "Cont." terminals on the electronic fan con-
trol.
Note: There should be only ONE motor lead going to the "Heat"
and "Cont." terminals.