12
CONTROL VOLTAGE CONNECTIONS
Do not use any type of power--stealing thermostat. Unit control
problems may result.
Use no. 18 American Wire Gage (AWG) color--coded, insulated
(35 C minimum) wires to make the control voltage connections
between the thermostat and the unit. If the thermostat is located
more than 100 ft from the unit (as measured along the control
voltage wires), use no. 16 AWG color--coded, insulated (35 C
minimum) wires.
Remove knockout hole located in the heat section panel adjacent
to the service access panel. Remove the rubber grommet from the
installer’s packet and install grommet in the knockout opening.
Provide a drip loop before running wire through panel. Run the
low--voltage leads from the thermostat, through the inlet hole, and
into unit low--voltage splice box. Locate 18--gage wires leaving
control box. These low--voltage connection leads can be
identified by colors (See Fig. 11). Ensure the leads are long
enough to be routed into the low--voltage splice box (located
below right side of control box). Route leads through hole in
bottom of control box and make low--voltage connections (See
Fig. 11). Secure all cut wires, so that they do not interfere with
operation of unit.
Easy Select
t
-- 574B
EASY SELECT
t
CONFIGURATION TAPS FOR 574B
Easy Select taps are used by the installer to configure a system.
The ECM motor uses the selected taps to modify its operation to
a pre--programmed table of airflows.
The unit must be configured to operate properly with system
components with which it is installed. To successfully configure a
basic system (see information printed on circuit board label
located next to select pins), move the 6 select wires to the pins
which match the components used (See Fig. 12).
EASY SELECT
HEATER/MOTOR
GAS HEAT/CFM
090
1250
SEC1
SEC2
J1
AC/HP SIZE
036
030
024
018
AC
HP-COMFORT
HP-EFF
NOM
HI
ENH
LO
SYSTEM TYPE
AC/HP CFM ADJUST
ON/OFF DELAY
CONTINUOUS FAN
MED
HI
YEL
LO
AUX1
HUM1
AUX2
24VAC
GRY
HUM2
YEL
WHT
BLK
ORN
BLU
VIO
060
1100
040
800
0
90
30
90
0
0
N/A
TM
J2
D
H
R
W
1
W
2
Y
1
Y/Y
2
G
O
C
9 PIN CONNECTOR
ICM PRINTED CIRCUIT BOARD
12 PIN CONNECTOR
A
B
C
D
E
F
C01039
Fig. 12 -- Detail of SPP Printed--Circuit Board
a. GAS HEAT/CFM--SELECT GAS HEAT INPUT
SIZE Factory selected gas heat size should correspond
to unit label.
b. AC/HP SIZE-- SELECT SYSTEM SIZE
INSTALLED
Factory selected air conditioner size should correspond
to capacity of unit installed. Installer should verify air
conditioner size to ensure that airflow delivered falls
within proper range for the size unit installed. This
applies to all operational modes.
c. SYSTEM TYPE SELECT SYSTEM TYPE
INSTALLED
Factory selected on 574B for AC--Air conditioner.
For Gas Heat/Electric Cool Unit--AC must be selected.
d. AC/HP CFM ADJUST--SELECT NOMINAL, LOW,
OR HIGH AIRFLOW
The AC/HP CFM Adjust select is factory set to the
NOM tap. The CFM Adjust selections NOM/LO will
regulate airflow supplied for all operational modes,
except non--heat pump heating modes. HI provides 15
percent airflow over nominal unit size selected and LO
provides 10 percent airflow below nominal unit size
selected. Adjust selection options are provided to
adjust airflow supplied to meet individual installation
needs for such things as noise, comfort, and humidity
removal (See Fig. 12, D as indicated).
e. ON/OFF DELAY-- SELECT DESIREDTIME
DELAY PROFILE
Four motor operation delay profiles are provided to
customize and enhance system operation (See Fig. 12,
E as indicated).
Selection options are:
(1.) The standard 90 sec off delay (Factory Setting) at
100 percent airflow in cooling mode. In heating
mode, IGC will control 45 sec on delay with no
airflow and 45 sec off delay.
(2.) A 30 sec cooling delay with no airflow/ 90 sec
off delay at 100 percent airflow profile is used
when it is desirable to allow system coils time to
cool--down in conjunction with the airflow in
heating mode.
(3.) A no delay option used for servicing unit or
when a thermostat is utilized to perform delay
functions in cooling mode. In heating mode IGC
will control 45 sec on delay with no airflow and
45 sec off delay.
(4.) ENH-- Not recommended for 574B
f. CONTINUOUS FAN SELECT DESIRED FAN
SPEED WHEN THERMOSTAT IS SET ON
CONTINUOUS FAN
(1.) LO speed--Factory setting, 50 percent cooling
mode airflow.
(2.) MED speed--Move connector to MED, 65 percent
cooling mode airflow.
(3.) HI speed--Move connector to HI, 100 percent
cooling mode airflow (See Fig. 12, F as
indicated).
g. LOW--VOLTAGE CIRCUIT FUSING AND
REFERENCE
The low--voltage circuit is fused by a board--mounted
5--amp automotive fuse placed in series with the
transformer SEC2 and the R circuit. The C circuit of
the transformer is referenced to chassis ground through
a printed circuit run at SEC1 connected to metal
standoff marked with ground symbol.
574B
