W415-0919 / D / 03.27.13
48
18.4 DehUMIDIfICaTIon - eCM 2.3
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.
There are three jumper wires in front of the thermostat input terminal block that are used in different applica-
tions. These jumper wires may be cut or clipped when the option is not desired.
• The jW38 jumper connects y1 to y2 so that the ECm motor only recognizes one input. This is used with a
single stage thermostat to allow you to get 2nd stage heating.
• The jW39 jumper connects o to R for using a heat pump in the non-heat pump mode (cooling only).
• The jW40 jumper connects DEhum to R for dehumidification active all the time.
18.5 seTTInG bloWeR “on” anD “off” TIMInGs - eCM 2.3 MoDels onlY
blower on/off delays are handled by ECm motor programming. The control de-energizes the ECm heat signal
when the gas valve de-energizes. Features of this ECm variable speed motor are that it will deliver a constant
airflow within a wide range of external static pressures, and also includes:
Soft Start:
This ECm variable speed motor will slowly ramp up to the required operating speed. This feature in
the heating cycle allows the heat exchanger to reach operating temperature before the set heat speed, which
minimizes noise and increases comfort.
Soft Stop:
At the end of the heating or cooling cycle, the ECm variable speed motor will slowly ramp down.
This feature allows for increased energy efficiency, and reduced noise levels.
18.6 ConTInUoUs fan opeRaTIon
When the thermostat continuous fan (g) switch is on with-
out a call for heat or cooling, the indoor fan is immediately
energized up to 50% of the cooling speed. The fan remains
energized as long as the call for fan remains without a call for
heat or cooling. This feature allows continuous circulation of
air between calls for heating or cooling.
If a call for heat (W) occurs during continuous fan, the blower
will remain energized, the call for heat overides the call for
fan.
If a call for cool (y) occurs simultaneously with the call for fan
(g), the call for cool overrides the call for fan .
TABLE 12 - CONTINUOUS FAN CFM
Input
K/Btu/hr
Motor
HP
COOL
Jumper
ADJUST
Jumper
Continuous
Fan (CFM)
045-2
⅓
A
NoRm
600
060-3
½
A
NoRm
600
080-3
½
A
NoRm
825
100-5
¾
A
NoRm
865
120-5
1
A
NoRm
930
Note:
Moving the ADJUST jumper from the NoRM
position to the (+) or (-) position will increase or lower
the continuous fan CFM by 15%
5A FUSE
24 VAC MOLEX
ICM
INTERFACE
THERMOSTAT
TERMINALS
FAULT CODE
BUTTON
RED STATUS
LED
HEAT STAGING
JUMPER P5
120 VAC NEUTRAL
CONNECTIONS
120 VAC
MOLEX
POWER
HUMIDIFIER
ELECTRONIC
AIR CLEANER
PARK
TERMINALS
FIGURE 36 - INTEGRATED FURNACE IGNITION CONTROL
FIGURE 39
