Trane S9V2B040U3PSBB Installer's Manual page 103

4. When PS1 closes, the ignitor relay on the IFC will
close. The ignitor is energized and warm up is
approximately 20 seconds.
5. After the ignitor warm up, the 1
relay is closed, energizing the 1
solenoid to allow ignition.
6. The first burner will ignite and flame will crossover
to the remaining burners, establishing current to
the flame sensor. Flame sensing must take place
within 4 seconds.
N N o o t t e e : : There are two flame sense pads located on
the IFC, marked "FP". To measure the flame
current, use a VOM set to DC volts. 1VDC = 1
micro-amp. Flame current will vary
depending on the type of meter used. Typical
flame current ranges from 0.75 – 3.0 micro-
amps (0.75 – 3 VDC).
7. Once flame sense has been achieved, a timer on the
IFC starts and after the "Blower On" delay has
completed, the indoor blower will energize and run
st
at the 1 stage gas heating speed. The seven
segment LED for example will alternately read:
HT1 = Gas heating, Stage 1
ARF = Airflow
060 = 600 requested cfm (value shown x 10)
8. R-W2 contacts close on the thermostat sending
24VAC to the W2 low voltage terminal of the IFC.
Technician should read 24VAC from W2 to B/C. The
seven segment LED will read "HT2".
9. The IFC then energizes the 2
The inducer ramps to 2
gas valve relay on the IFC closes, energizing second
stage gas valve. The indoor blower motor will ramp
nd
up to the 2 stage gas heating speed. The seven
segment LED for example will alternately read:
HT2 = Gas heating, Stage 2
ARF = Airflow
123 = 1230 requested cfm (value shown x 10)
10. The IFC monitors PS2 for closure and if PS2 does
not close within 45 seconds, a PS2 open error will
be declared and the furnace will operate in 1
stage. If PS2 closes, 2
continue until the thermostat R-W2 contacts open.
N N o o t t e e : : If PS2 does not close within the 45 second time,
the IFC will wait 10 minutes and repeat step 9. If
on the third attempt during the same heating call,
PS2 does not close within the 45 second proving
time, the unit will lock out 2
heating calls are removed or the power is cycled
to the furnace.
11. When the temperature raises enough to satisfy the
thermostat setting, contacts R-W2 will open, 2
stage gas valve will close, the indoor blower motor
st
will ramp down to 1
continue to run until R-W1 contacts open.
12. When the temperature raises enough to satisfy the
thermostat setting, contacts R-W1 will open.
18-CE01D1-1M-EN
st
stage gas valve
st
stage gas valve
nd
stage inducer relay.
nd
stage, the second stage
st
nd
stage gas heating will
nd
stage until the
nd
stage, and the unit will
13. The gas valve relay will open, closing the gas valve.
The inducer will continue to run for approximately 5
seconds to remove any combustion byproducts
from inside the furnace.
14. The indoor blower continues to run to remove heat
from the heat exchangers. This blower off time is
field adjustable through the IFC menu setup option.
The seven segment LED will read "IDL" = Idle, no
thermostat demand.
S S i i n n g g l l e e S S t t a a g g e e C C o o o o l l i i n n g g
1. R-Y1-G contacts on the thermostat close sending
24VAC to the Y1 and G low voltage terminals on the
IFC. Technician should read 24VAC between Y1-B/C
and between G-B/C.
N N o o t t e e : : Factory supplied Y1-O jumper must remain in
place for proper seven segment LED readout. If
removed, seven segment LED will read " HP1 ".
2. 24VAC is sent to the OD unit via thermostat wiring.
3. The indoor blower ramps to the cooling airflow.
The seven segment LED for example will alternately
read:
CL1 = Cooling, Stage 1
ARF = Airflow
080 = 800 requested cfm (value shown x 10)
4. When the temperature is lowered enough to satisfy
the thermostat setting, contacts R-Y1-G will open.
5. The OD unit shuts off and the indoor blower shuts
off, unless a blower off delay has been enabled in
the IFC setup menu options. The seven segment
LED will read "IDL" = Idle, no thermostat demand.
T T w w o o S S t t a a g g e e C C o o o o l l i i n n g g
1. R-Y1-G contacts on the thermostat close sending
24VAC to the Y1 and G low voltage terminals on the
IFC. Technician should read 24VAC between Y1-B/C
and between G-B/C.
N N o o t t e e : : Factory supplied Y1-O jumper must remain in
place for proper seven segment LED readout. If
removed, seven segment LED will read " HP1 ".
2. 24VAC is sent to the OD unit via thermostat wiring
st
energizing 1 stage compressor operation.
3. The indoor blower ramps to the 1
airflow. The seven segment LED for example will
alternately read:
CL1 = Cooling, Stage 1
ARF = Airflow
080 = 800 requested cfm (value shown x 10)
4. R-Y2 contact on the thermostat closes sending
24VAC to Y2 low voltage terminal on the IFC.
Technician should read 24VAC between Y2 and B/C.
5. 24VAC is sent to the OD unit via thermostat wiring.
6. The indoor airflow ramps to 2
airflow. The seven segment LED for example will
read:
CL2 = Cooling, Stage 2
S S e e q q u u e e n n c c e e o o f f O O p p e e r r a a t t i i o o n n
st
stage cooling
nd
stage cooling
103