30
Orange
High
Common/Neutral
Medium Low
Circulator Blower Speeds
Low
Red
Medium Blue
Black
White
XV
XV
XV
XV
XV. NO
. NO
. NO
. NO
. NORM
RM
RM
RM
RMAL SEQUEN
AL SEQUEN
AL SEQUEN
AL SEQUEN
AL SEQUENCE O
CE O
CE O
CE O
CE OF OPERA
F OPERA
F OPERA
F OPERA
F OPERATI
TI
TI
TI
TIO
O
O
O
ON
N
N
N
N
P
OWER
U
P
The normal power up sequence is as follows:
•
115 VAC power applied to furnace.
•
Integrated control module performs internal checks.
•
Integrated control module LED will light.
•
Integrated control module monitors safety circuits
continuously.
•
Furnace awaits call from thermostat.
H
EATING
M
ODE
(M
ODE
DIP
SWITCH
IS
SET
TO
“1 STG”
POSITION
)
The normal operational sequence in heating mode is as follows:
•
R and W thermostat contacts close, initiating a call for heat.
•
Integrated control module performs safety circuit checks.
•
Induced draft blower is energized for 15 second pre-purge
period causing pressure switch contacts to close.
•
Igniter warm up begins after 15 second prepurge expires.
•
Low and high stage gas valves open at end of igniter warm
up period, delivering gas to burners and establishing flame.
•
Integrated control module monitors flame presence. Gas
valve will remain open only if flame is detected.
•
Circulator blower is energized on high heat speed following
a fixed thirty second blower on delay. Electronic air cleaner
terminals are energized with circulator blower.
•
Furnace operates; integrated control module monitors
safety circuits continuously.
•
R and W thermostat contacts open, completing the call for
heat.
•
Gas valve closes, extinguishing flame.
•
Induced draft blower is de-energized following a fifteen
second post purge.
•
The circulator blower remains at high heat speed for thirty
seconds. The circulator blower then switches to low heat
speed for the remainder of the selected heat off delay period.
For example, the selected heat off delay period is 150
seconds. The circulator blower operates at high heat for 30
seconds and at low speed for 150 - 30 = 120 seconds.
(M
ODE
DIP S
WITCH
IS
SET
TO
“2 STG”
POSITION
)
The normal operational sequence in sequence is as follows:
•
R and W thermostat contacts close, initiating a call for heat.
•
Integrated control module performs safety circuit checks.
•
Induced draft blower is energized for 15 second prepurge
period causing pressure switch contacts to close.
•
Igniter warm up begins after 15 second prepurge expires.
•
Low and high-stage gas valves open at end of igniter warm
up period, delivering gas to burners and establishing flame.
•
High-stage gas valve closes after five seconds; low-stage
gas valve remains open.
•
Integrated control module monitors flame presence. Gas
valve will remain open only if flame is detected.
•
Circulator blower is energized on low heat speed following
a fixed thirty second blower on delay. Electronic air cleaner
terminals are energized with circulator blower.
•
Furnace is now operating in low-stage heating mode.
•
Furnace operates; integrated control module monitors
safety circuits continuously.
•
If low-stage delay period expires, control will shift operation
from low-stage heating mode operation to high-stage
heating mode operation. Control will energize circulator
blower high heat speed and high stage gas valve.
•
Furnace is now operating in high-stage heating mode.
•
R and W thermostat contacts open, completing the call for
heat.
•
Induced draft blower is de-energized following a fifteen
second post purge.
•
Circulator blower is de-energized following a heat off delay
period (selectable 100 or 150 seconds; factory set at 150
seconds).
If the furnace is operating in the low-stage heating mode
when thermostat contacts open, circulator remains at low
heat speed for the selected delay off period.
If the furnace is operating in high-stage heating mode when
the thermostat contacts open, the circulator blower remains
at high heat speed for thirty seconds. The circulator blower
then switches to low heat speed for the remainder of the
selected heat off delay period. For example, the selected
heat off delay period is 150 seconds. The circulator blower
operates at high heat for 30 seconds and at low speed for
150 - 30 = 120 seconds.
•
Furnace awaits the next call from thermostat.