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Single Stage Thermostat Operation
(A95DF2V and 95G2DFV Models )
The automatic heat staging option allows a single stage
thermostat to be used with two stage furnace models
(A95DF2V or 95G2DFV). To activate this option, move the
jumper pin (see Figure 53) to desired setting (5 minutes or
10 minutes). The furnace will start on 1st stage heat and
stay at 1st stage heat for the duration of the selected time
before switching to 2nd stage heat.
W1 on the control board must be connected to W1 on the
thermostat.
AUTOMATIC HEAT STAGING JUMPER
Figure 53
Humidifier
Terminals are provided on the integrated ignition/blower
control board for connection to a 120-volt humidifier. The
"HUM" terminal is energized whenever the thermostat
calls for heat. See the furnace wiring diagram for specific
connection information.
Electronic Air Cleaner
Terminals are provided on the integrated ignition/blower
control board for connection of a 120-volt electronic air
cleaner. The "EAC" terminal is energized whenever the
thermostat calls for heat, cooling, or continuous blower. See
furnace wiring diagram for specific connection information.
Variable Speed Features
This furnace is equipped with a variable speed circulation
air blower motor that will deliver a constant airflow within a
wide range of external static pressures. Other features of
this variable speed motor include:
Soft Start
The variable speed motor will slowly ramp up to normal
operating speed. This minimizes noise and increases
comfort by eliminating the initial blasts of air encountered
with standard motors.
507052-04
Soft Stop
At the end of a cooling or heating cycle, the variable speed
motor will slowly ramp down after a short blower "off" delay.
If continuous blower operation has been selected, the
variable speed motor will slowly ramp down until it reaches
the airflow for that mode.
Passive and Active Dehumidification
Passive Dehumidification
For situations where humidity control is a problem, a
dehumidification feature has been built into the variable
speed motor. At the start of each cooling cycle, the variable
speed motor will run at 82% of the rated airflow for 7.5
minutes. After 7.5 minutes has elapsed, the motor will
increase to 100% of the rated airflow.
Active Dehumidification
To achieve additional dehumidification, clip the jumper
wire located below the DEHUM terminal on the integrated
ignition/blower control board and connect a humidity
control that opens on humidity rise to the DEHUM and R
terminals. The DEHUM terminal on the control board must
be connected to the normally closed contact of the humidity
control so that the board senses an open circuit on high
humidity. In this setup, the variable speed motor will operate
at a 30% reduction in the normal cooling airflow rate when
there is a call for dehumidification.
Both the passive and active dehumidification methods
described above can be utilized on the same furnace.
Circulating Airflow Adjustments
Cooling Mode
The units are factory set for the highest airflow for each
model. Adjustments can be made to the cooling airflow by
repositioning the jumper plug marked COOL – A, B, C, D (see
Figure 52). To determine what CFM the motor is delivering
at any time, count the number of times the amber LED on
the control board flashes. Each flash signifies 100 CFM;
count the flashes and multiply by 100 to determine the actual
CFM delivered (for example: 10 flashes x 100 = 1000 CFM).
Heating Mode
These units are factory set to run at the middle of the heating
rise range as shown on the unit rating plate. If higher or
lower rise is desired, reposition the jumper plug marked
HEAT - A, B, C, C (see Figure 50) . To determine what
CFM the motor is delivering at any time, count the number
of times the amber LED on the control board flashes. Each
flash signifies 100 CFM; count the flashes and multiply by
100 to determine the actual CFM delivered (for example:
10 flashes x 100= 1000
Issue 1621
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Page 39 of 58
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