26
441 01 5003 01
Specifications are subject to change without notice
Ignitor Location
in (mm)
Figure 31
NOTE:
Flame sensor has a different orientation in all 050 models.
2
1/
16
(52.39)
1
/
4
(6.4)
5
/
16
(8)
Air Temperature Rise Check
!
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.
CAUTION
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 for 10 minutes with all the registers and duct
dampers open by using a jumper wire on R to W thermostat
connections on the control board.
3. Take readings and compare with range specified on rating
plate.
4. If the air temperature rise is not in the correct range, the blower
speed must be changed. A higher blower speed will lower the
temperature rise. A lower blower speed will increase the
temperature rise.
5.
Remove the jumper wire after the adjustments are complete.
Changing Blower Speed
ELECTRICAL SHOCK HAZARD.
Failure to disconnect power could result in personal
injury or death.
Turn OFF power to furnace before changing speed
taps.
!
NOTE
: The speed taps that the manufacturer sets at the factory for
this furnace 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 predict the static pressure that
will be applied to the furnace, it is the responsibility of the
installer dealer/contractor to select the proper speed tap leads
for the application when the furnace 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 furnace control as
well as location of unused blower motor speed leads. Use the
chart (
Table 9
) to determine the blower motor speed settings.
Table 9
Blower Speed Chart
Wire Color
Motor Speed
Black
High
Orange
*
Med--High
Blue
Med--Low
Red
Low
*
Med--High speed may not be provided on all models.
2. Change the heat or cool blower motor speed by removing the
motor speed lead from the “
Heat
” or “
Cool
” terminal and
replace it with the desired motor speed lead from the
“M1” or
“M2
” location. Connect the wire previously removed from the
“
Heat
” or “
Cool
” terminal to the vacated
“M1” or “M2
”
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
“M1” or “M2”
location or tape off. Attach a jumper between
the
“Heat”
and
“Cool”
terminals and the remaining motor
speed lead.
Note:
When using the same speed on 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
“M1” or “M2”
location.
Thoroughly check the system after modification to ensure the
proper operation of the circulating air blower in all modes of
operation.
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 Continuous- Fan Operation
A terminal is provided on the furnace control board located in the
circulating air 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. EAC is not
powered in this mode.
Thoroughly check the system after modification to ensure the
proper operation of the circulating air blower in all modes of
operation.
Separate speed selections for Heat, Cool, and
Continuous- Fan
Connect low speed lead from circulating air motor to the
“Cont”
terminal at the furnace control board. The appropriate motor leads
should already be connected to the
“Heat”
and
“Cool”
terminals.
