TemperatureRise Check
The blower speed MUST be set to give the correct air temperature
rise through the furnace as marked on the rating plate.
Temperature rise is the difference between supply and return air
temperatures.
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
registers 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.
ChangingBlowerSpeed
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in
personal injury or death.
Turn OFF power, lockout and tag switch with a
suitable warning label, to furnace before changing
speed taps.
NOTE: The speed taps that the manufacturer 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 application when the unit is installed.
If it is necessary to change speeds, refer to steps below.
REDUCED FURNACE LIFE HAZARD
Failure to follow this caution may result in reduced
furnace life.
Use ONLY the blower motor speed taps insert
indicated in the Circulation Air Blower Data for
setting air temperature rise.
Wire Color
Black
Orange*
Blue
Red
Blower Speed Chart
Motor Speed
High
Med-High
Medium
Low
* Med-High speed may not be provided on all models.
Refer to Furnace Wiring Diagram for location of the heating
and cooling speed taps located on the furnace control as
well as location of unused blower motor speed leads. Use
the chart (Table 14) to determine the blower motor speed
settings.
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 lead from the
"Unused Motor Lead" location. Connect the wire
previously removed from the "Heat" or "Cool" terminal to
the vacated "Unused Motor Lead" 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 Lead" location. Attach a jumper
between the "Heat" and "Cool" terminals and the remaining
motor speed lead.
Note: For motors with (4) speed leads, it will be necessary
to tape off the terminal of the motor speed lead removed
from the "Heat" or "Cool" terminal with electrical tape since
an open terminal will not be available at the "Unused Motor
Lead" location.
Continuous-Fan Operation using "G"
Energizing the "G" terminal on the furnace control provides
continuous fan operation. This is done by connecting the G
terminal of the thermostat to the G terminal on the furnace control.
When the FAN switch is turned from auto to ON the fan will operate
continuously at "HEAT" speed. EAC will be energized in this
mode.
NOTE: In heating, the fan will turn off during furnace ignition and
warm up then restart at heating speed.
Hard Wired ContinuousFan Operation
A terminal is provided on the furnace control board 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 wilt 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
operation.
Separatespeedselectionsfor Heat, Cool,and
ContinuousFan
Connect low speed lead from circulating motor to the "Cont."
terminal at the furnace control. The appropriate motor leads
should already be connected to the "Heat" and "coor' 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
between the "Heat" and "Cont." terminals on the furnace control.
Note: There should be only ONE motor lead going to the "Heat"
and "Cont." terminals.
44
Specifications are subject to change without notice
44001 102404
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