S9200U1000 UNIVERSAL HOT SURFACE IGNITION INTEGRATED FURNACE CONTROL
15
69-2075EF—01
Refer to Fig. 11 on page 18 for the control sequence
diagram.
Humidity Control
The line voltage humidifier output energizes anytime the
inducer energizes.
Electronic Air Cleaner
The line voltage EAC output energizes anytime the
circulator is energized.
II. CHECK SAFETY SHUTOFF
OPERATION
1.
Shut off the gas supply at the manual gas valve
ahead of the appliance.
2.
Set the thermostat to call for heat. System should
operate as indicated in Fig. 9 on page 17.
3.
Following lockout, open the manual gas valve and
make sure no gas is flowing to the burner.
Error Conditions
The following section lists the S9200U1000 operating
sequence for the stated error conditions.
Main Valve Sensing
The S9200U1000 monitors the valve output during the
following conditions:
— Idle Mode
— Non-fault related states of Ignition sequence
— States related to the pressure switch fault
— When limit switch is open and inducer is no longer
running, up to 180 seconds following the limit
switch opening
In other conditions/states, main valve feedback is not
monitored.
MAIN VALVE FEEDBACK PROCESSING
If the inducer is off or on while the pressure switch is still
open, and voltage is detected on the valve for longer than
the fault debouncing time (miswire):
— All outputs are turned off except for the inducer,
which is kept energized.
— The circulator energizes at the heat speed.
— If a call for cool occurs, the control energizes the
circulator at cool speed after the appropriate
delay.
— An error code flashes indicating there is a hard-
ware malfunction. See Table 12 on page 20.
— An EnviraCOM™ alarm is active and sent on the
bus. See Table 14 on page 22.
If voltage is no longer detected on the valve for more than
the fault debouncing time:
— If the number of detected gas valve welded/mis-
wire conditions have not reached 5 (since last
power-up), the S9200U1000 proceeds to Soft
Lockout. The S9200U1000 remains in Soft Lock-
out for the Auto Restart Delay.
— If the number of detected gas valve welded/mis-
wire conditions have reached 5 (since last power-
up), the S9200U1000 enters Hard Lockout, where
it remains until power reset.
An EnviraCOM™ alarm indicating that manual
reset is needed is active and sent on the bus. See
Table 14 on page 22.
If the inducer is energized or the pressure switch is closed
and the inducer is not energized (pressure switch is stuck
closed) and the main valve relay contacts are sensed
closed even though the relay is not energized (welded
contacts):
— An error code flashes indicating there is a hard-
ware malfunction. See Table 12 on page 20.
— An EnviraCOM™ alarm is active and sent on the
bus. See Table 14 on page 22.
— The inducer immediately switches off in an
attempt to open the pressure switch. If, after 5
seconds, flame is sensed or voltage is still sensed
on the main valve, the S9200U1000 energizes the
inducer and circulator on heat speed.
If flame is not sensed and voltage on the main valve is no
longer detected:
— The S9200U1000 proceeds to Soft Lockout if the
number of detected gas valve welded/ miss-wire
conditions have not reached 5 (since last power-
up). The S9200U1000 remains in Soft Lockout for
the Auto Restart Delay period. Otherwise, the
S9200U1000 will enter Hard Lockout where it will
remain until power is reset.
If voltage is not detected on the valve for longer than the
fault debouncing time during a period when the valve is to
be energized (contacts failed to make):
— the S9200U1000 proceeds as if flame is not
sensed. If Soft Lockout is entered due to this con-
dition:
• An error code flashes indicating failed
hardware. See Table 12 on page 20.
• An EnviraCOM™ alarm is active and sent on
the bus. See Table 14 on page 22.
Flame Out of Sequence
The S9200U1000 does not take action on flame sensed in
Idle Mode when there is no call for heat present.
If the S9200U1000 is servicing a call for heat and flame is
sensed when it is not expected to be present, the ignition
and fan sequences are not allowed to progress and the
S9200U1000 stays in its current state. The exception is
Igniter Warm-up, where the S9200U1000 proceeds to
Prepurge.
If the sensed flame goes away before the False Flame
Recognition Period, the ignition sequence proceeds as
normal.
If however the sensed flame lasts longer than the False
Flame Recognition Period:
— The igniter de-energizes, the inducer energizes,
and the circulator energizes at heat speed.
— An error code flashes indicating flame is sensed
out of sequence. See Table 12 on page 20.
— An EnviraCOM™ alarm is active and sent on the
bus. See Table 14 on page 22.
— When the sensed flame goes away, the
S9200U1000 proceeds to Postpurge, followed by
Idle Mode at which time the error code is cleared.
