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100% CFM
OFF
50% CFM
½ min
•
Profile C ramps up to 82% of the full cooling demand airflow
and operates there for approximately 7 ½ minutes. The motor
then steps up to the full demand airflow. Profile C also has
a 1 minute/100% OFF delay.
82% CFM
OFF
7 ½ min
•
Profile D ramps up to 50% of the demand for ½ minute,
then ramps to 82% of the full cooling demand airflow and
operates there for approximately 7 ½ minutes. The motor
then steps up to the full demand airflow. Profile D has a 1/
2 minute at 50% airflow OFF delay.
82% CFM
OFF
50% CFM
½ min
7 ½ min
*
Ramping
Profile
Tap A
Ramping
Profile
Tap B
Ramping
Profile
Tap C
Ramping
Profile
Tap D
Ramping Profiles
(*indicates factory setting)
6. Select the heating speed from the heating speed chart in
the Product Data Book applicable for your model*. The
adjust setting (already established by the cooling speed
selection) determines which set of speeds are available.
The selected speed must provide a temperature rise within
the rise range listed with the particular model.
Example:
The 70 kBtu is set for 990 CFM on cooling,
the "ADJUST" is set to "-" (minus). The four heating speeds
available are "A Minus", "B Minus", "C Minus", and "D Minus".
"B Minus" has a rise of 56°F for both stages which is within
the 30-60°F rise range for the 70 kBtu. This setting will
keep electrical consumption to a minimum. Set the "Heat"
speed DIP switches to "A".
7. Select the desired "heating" speed tap by positioning
switches 7 and 8 appropriately. Refer to figure above. Turn
off power to furnace for a minimum of 10 seconds, allowing
motor to reset and recognize new speed selection. Turn
on power to furnace. Verify selected CFM by counting the
green CFM LED blinks.
In general lower heating speeds will: reduce electrical
consumption, lower operating sound levels of the blower, and
increase the outlet air temperature delivered to the home.
speeds available allow the blower performance to be optimized
for the particular homeowner's needs.
IO-247A
100% CFM
1 m in
Cooling Dem and
100% CFM
100% CFM
1 min
Cooling Demand
100% CFM
50% CFM
½ min
Cooling Demand
8
7 6 5 4
3 2 1
O
O
F
F
F
F
8
7 6 5 4
3 2 1
O
O
N
F
F
8
7 6 5 4
3 2 1
O
O
N
F
F
8
7 6 5 4
3 2 1
O
O
N
N
4 3 2 1
8 7
Cooling
Speed
Tap A
OFF
8 7
4 3 2 1
Cooling
Speed
Tap B
8 7
4 3 2 1
Cooling
Speed
Tap C
8 7
4 3 2 1
*
Cooling
Speed
Tap D
Cooling Speed Taps
*
(
indicates factory setting)
OFF
A
B
H
DJUST
LOWER
The integrated control module provides a selectable heat off delay
function. The heat off delay period may be set to 90, 120, 150,180
seconds using the DIP switches or jumper provided on the control
module. The delay is factory shipped at 150 seconds but may be
changed to suit the installation requirements and/or homeowner
preference. Refer to the following figures for switch positions and
corresponding delay times.
OFF
C
B
IRCULATOR
LOWER
NOTE: Items in this section refer to the air circulator blower fan,
NOT to the induced draft blower. The induced draft blower timing
sequence is not adjustable. The circulator blower fan timing is
adjustable only on models with optional "heating fan OFF delay"
adjustment pins or switches (Figure 28). It is NOT adjustable in
any other circumstances.
As shipped, the circulator blower fan will remain on for 150 seconds
after the gas valve closes. The circulator blower then ramps down
to "OFF" during the 30 seconds following the heat off delay period.
When a call for cooling occurs, the circulator fan comes on and
remains on for 45 seconds after the call for cooling ends. During
normal heating operation, the circulator fan will come on
approximately 37 seconds after the gas valve opens.
90
SECOND
DELAY
150
SECOND
DELAY
Switches viewed in an upflow installation.
The
25
8 7
4 3 2 1
*
Heating
Normal
Speed
Tap A
O
O
O
O
F
F
F
F
F
F
F
F
8 7
4 3 2 1
*
Heating
+ (Plus)
Speed
Adjust
Tap B
O
O
O
O
F
N
F
N
F
F
8
7
4
3 2 1
Heating
- (Minus)
Speed
Adjust
Tap C
O
O
O
O
N
F
N
F
F
F
Heating
Adjust Taps
Speed
*
(
indicates factory setting)
Tap D
O
O
N
N
Heating Speed Taps
*
(
indicates factory setting)
O
D
EAT
FF
ELAY
Heat Off
3
Delay
ON
2
90 Seconds
ON
1
3
Heat Off
Delay
ON
2
120 Seconds
OFF
1
*
3
Heat Off
Delay
OFF
2
150 Seconds
ON
1
3
Heat Off
Delay
OFF
2
180 Seconds
OFF
1
Heat Off Delay
(* indicates factory setting)
Heat Off Delay S
F
T
A
AN
IMING
DJUSTMENT
120
SECOND
DELAY
180
SECOND
DELAY
Adjustment Switches
8 7
4 3 2 1
O
O
F
F
F
F
8 7
4 3 2 1
O
O
F
N
F
8 7
4 3 2 1
O
O
N
F
F
8 7
4 3 2 1
O
O
N
N
12/04
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Troubleshooting
