Main Burner
10-10-78
TemperatureRiseCheck
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 blow-
er speed will lower the temperature rise. A lower blower
speed wil! increase the temperature rise.
ChangingBlowerSpeed
Electrical shock hazard.
Turn OFF power to furnace before changing speed
taps.
Failure to do 8o can result in death and/or personal in-
jury.
NOTE: The speed taps that the manufacturer sets from the facto-
ryfor this product are based on a nominal 400 CFM per ton cool-
ing 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.
1. Refer to Furnace Wiring Diagram for location of the heating
and cooling speed taps located on the electronic fan con-
trol as well as location of unused blower motor speed
leads. Use the chart (Table 9) to determine the blower mo-
tor speed settings.
Blower Speed Chart
Wire Color
Black
Orange*
Blue
Red
Motor Speed
High
Med-High
Medium
Low
* Med-High speed may not be provided on all models,
Change the heat or cool blower motor speed by removing
the motor lead from the "Heat" or "Cool" terminal and re-
place it with the desired motor speed lead from the "Un-
used Motor Lead" location. Connect the wire previously
removed from the "Heat" or "Cool" terminal to the vacated
"Unused Motor Lead" terminal.
If the same speed must be used for both heating and cool-
ing, 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 "Neat" or "Cool" terminal with electrical tape since
an open terminal will not be available atthe "Unused Mo-
tor Lead" location.
ContinuousFan 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.
Heatingand ContinuousBlowerSpeed 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.
[_ 440 01 101004
To Next Page
Loading...
Need help?
General
