SETUP PROCEDURES (ICM BLOWER MOTORS)
The ICM blower motor operating mode selections are made on EZ-SELECT airflow control with color-coded jumper wires. Factory jumper
settings have large bold circles marked around pins. (See Fig. 6.) BLUE, RED, and GREEN jumpers are shown at factory settings. Furnaces with
ICM blower motors are not approved for twinning.
I.
GAS HEATING
1. The VIOLET wire is factory-connected to 1 of the 4 pins (A, B, C, or D) on Airflow Selector. Pin selection can be checked by noting the
"PIN" marking in lower right-hand corner of furnace rating plate.
2. Gas heating air temperature rise is selected on EZ-SELECT airflow control with RED jumper wire. The selections are MID (midpoint of
temperature rise range marked on rating plate), HI (approximately the high end of rise range), and M-HI (about half-way between MID and
HI). Select rise by moving WHITE connector on RED jumper wire to desired pin position. This setting selects rises for high- and low-gas
heating.
II.
COOLING AND HEAT PUMP HEATING
1. Cooling and heat pump selections can be determined from Table 4. Selections are made by moving WHITE connector on appropriately
colored YELLOW jumper wire to desired pin position. Power must be cycled off and then on for Cool Size selection to take effect. Power
need not be cycled off and on for CFM/TON to take effect.
The YELLOW COOL SIZE jumper is used to select airflow CFM to match needed tons for cooling or heat pump system. The BLUE
CFM/TON jumper is used to select a slight adjustment to airflow CFM. The traditional cooling and heat pump airflow is 400 CFM/TON.
An airflow CFM of 350 CFM/TON is used to attain the best efficiency with BDP units. An airflow CFM of 315 CFM/TON is used for
improved dehumidification and/or with undersized ducts. Additional humidity control can be attained by using a humidistat.
As an alternative to selecting 315 CFM per ton for cooling airflow CFM, an active de-humidification mode can be invoked by connecting
a humidistat in series with GREEN wire marked DEHUM connected to the 1/4-in. quick-connect terminal at G on 2-stage furnace control.
The humidistat contacts should open on a rise in humidity. When humidistat contacts open, airflow CFM will be reduced to 80% of selected
airflow CFM, except airflow CFM will not be reduced to less than 280 CFM per ton.
2. The ORANGE jumper wire selects cooling-only (AC) or heat pump heating and cooling, and selects heat pump heating best efficiency (HP
EFFY) or enhanced comfort (HP CMFT). HP EFFY provides the same heating airflow CFM as used for cooling. HP CMFT reduces heating
airflow CFM to 90% of cooling airflow CFM for a higher air temperature rise and better comfort.
III.
CONTINUOUS FAN
The GREEN jumper wire selects airflow CFM for continuous fan. LO provides 50% of airflow CFM used for single-speed cooling or 2-speed
cooling. MED provides 65% of this cooling airflow CFM. HI provides 100% of this cooling airflow CFM for continuous fan operation.
NOTE:
If HI is selected with a 2-speed cooling or heat pump system, airflow CFM remains at 100% of high-cooling/heating when system is in
low-cooling and heat pump low-heating mode. Continuous fan selection has no effect on gas heating airflow CFM.
TABLE 4—COOLING AND HEAT PUMP AIRFLOW SELECTIONS
TONS (12,000 BTUH)
1-1/2
2
2-1/2
3
3-1/2
4
5
Unit Size
COOL SIZES (YELLOW WIRE)
036060
LO
M-LO
M-HI
HI
—
—
—
048080
—
—
LO
M-LO
M-HI
HI
—
060100
060120
—
—
—
LO
M-LO
M-HI
HI
Operating Mode
CFM/TON (Blue Wire)
NOMINAL AIRFLOW (CFM)
Single-Speed
G and Y/Y2
(100%)
400
600
800
1000
1200
1400
1600
2000
350
525
700
875
1050
1225
1400
1750
315
500*
630
788
945
1102
1260
1575
2-Speed HI
G, Y1, and Y/Y2
(105%)
420
630
840
1050
1260
1470
1680
2100
368
551
735
919
1102
1286
1470
1838
331
496
662
827
992
1157
1323
1654
2-Speed LO
G and Y1
(65%)
—
500*
520
650
780
910
1040
1300
500*
500*
569
700†
796
910
1138
500*
500*
512
700†
700†
819
1024
* 500 CFM minimum airflow is set for use with electrostatic air cleaner.
† 700 CFM minimum airflow is set for 060 furnace sizes only for use with electrostatic air cleaner.
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